Cooking Greens in January

Morris Heading collards, a reliable winter crop. Photo Kathryn Simmons

Cooking Greens to Harvest in Central Virginia in January

Harvest in time! Freezing or Bolting Greens!

Outdoors, the temperatures continue to get colder in January. In our garden outdoors, there are collards, kale, spinach, and sometimes chard,  senposai, and Yukina savoy, and over-wintered cabbage (not for much longer!).

Hopefully there is also cabbage stored in the cooler. The most cold-hardy greens are what we depend on for the next two months.

Tatsoi in our hoophouse in December.
Photo Kathleen Slattery

From the hoophouse we continue harvesting chard, Chinese cabbage, kale, frilly mustards, pak choy, senposai, spinach, (including thinnings from the newer sowings),   tatsoi (thinnings from the newer sowings, whole plants from the September 7 sowing), Tokyo bekana/Maruba santoh plants, turnip greens, yukina savoy.

In the hoophouse, the extra warmth combined with the lengthening days causes some of the brassicas to start bolting. After the Winter Solstice the order of bolting of our hoophouse greens is: tatsoi #1 (meaning, our first sowing 9/6), Tokyo bekana, Maruba santoh (all in early January); pak choy, Chinese cabbage, Yukina Savoy #1 (late January); turnip greens #1 (mid-February); Komatsuna, Yukina Savoy #2, tatsoi #2, spinach #1, turnip greens #2 (early March); Senposai, turnips #3, (mid-March); Russian kales (early April); chard, beet greens, later spinach sowings (late April or even early May.)

Tokyo bekana in our hoophouse in late December.
Photo Pam Dawling

Our knowledge of what will bolt first informs our plan of where to put the new crops we want to plant. To make space to sow spinach on 1/16, we need to clear the Tokyo bekana (and Maruba santoh) and the first tatsoi by 1/14. We keep a close eye on the Chinese cabbage and pak choy. Normally these will bolt in January, and we harvest the whole plants this month. They will be followed by sowings of kale and collard starts for outdoors on 1/24.

Chines cabbage in November, not yet fully headed.
Photo Ethan Hirsh

It might seem sad, at first glance, that these big greens will bolt this month if we don’t harvest them in time, but in fact, it all works out rather well. The rate of growth of the “cut-and-come-again” leaf greens slows down in December and January, and while we eat the big heads of Tokyo bekana, Maruba santoh, Chinese cabbage, pak choy and the not-tiny tatsoi, we ignore the leaf greens, giving them more time to grow.

Pak Choy in our hoophouse in late December.
Photo Pam Dawling

December 15-February 15 is the slowest growing time for our hoophouse crops.

When the daylight is shorter than 10 hours a day, not much growth happens. The dates depend on your latitude. In Central Virginia, at latitude 38° North, this Persephone period (named by Eliot Coleman) lasts two months, from November 21 to January 21. We have found in practice, that soil temperature also affects the growth rate. And so we have a three week lag in early winter before the soil cools enough to slow growth, and then another 3 week lag  in January before it warms up enough again.

Transplanting spinach from a Speedling flat.
Photo Denny Ray McElya

Cooking Greens to Sow in Central Virginia in January

Outdoors, we sow nothing.

In the greenhouse we tidy up the workspace, “fire up” the germinator fridges (germination chambers made from the carcasses of dead fridges), and prepare our new Seedlings Schedule (see Special Topic for January below)

Around 1/17 we sow some fast early cabbage, such as the OP Early Jersey Wakefield and the hybrid Farao. (We sow lettuce and scallions then too, to keep them company.) At the end of January we sow spinach in Speedling flats if our hoophouse sowings have been insufficient. We have trialed the bare-root spinach against the Speedling spinach and both do equally well.

In the hoophouse, in mid-January we sow Spinach #4, to transplant in gaps in the hoophouse. We usually clear Tatsoi #1 to make space for this. Of the varieties we tried, Reflect does best for this planting, followed by Acadia and Escalade. This winter we have had difficulty buying Acadia and Escalade and are going to try Abundant Bloomsdale alongside Reflect.

Spinach seedlings in our hoophouse for bare-root transplanting.
Photo Pam Dawling

We also sow Spinach #5 for bare-root transplanting outdoors in February or early March under rowcover. This follows the Tokyo bekana or Maruba Santoh as noted above. Reflect and Acadia do well for this purpose, with Escalade close behind. We’ll have to improvise this spring.

In late January (1/24, 1/25), we sow kale and collards for transplanting outdoors in March. I have written before about how well these bare-root transplants work for us, compared to starting these seeds in flats in the greenhouse. It doesn’t work for lettuce at this time of year though – the tiny plants are too fragile and tender.

Vates kale seedlings in our hoophouse for bare-root transplanting outdoors.
Photo Pam Dawling

Follow-on Winter Hoophouse Crops

This is a  sequence of different crops occupying the same space over time. We try to keep the hoophouse fully planted all the time, and one aspect of this is knowing what we are going to sow when we pull an old crop out. Here’s our winter list:

  • 11/17: We follow our 1st radishes with 3rd  scallions
  • 12/23: 1st baby brassica salad mix with 5th radishes
  • 12/31: Some of our 1st spinach with our 2nd  baby lettuce mix
  • 1/15: Our 1st tatsoi with our 4th spinach
  • 1/16: Our Tokyo Bekana with spinach #5 for planting outdoors
  • 1/24: Our pak choy & Chinese cabbage with kale & collards for outdoors
  • 2/1: Our 2nd radishes with our 2nd baby brassica salad mix
  • 2/1: Our 1st Yukina Savoy with our 3rd mizuna/frilly mustards
  • 2/1: Some of our 1st turnips with our 3rd baby lettuce mix
  • 2/1: More of our 1st spinach with dwarf snap peas

Cooking Greens to Transplant in Central Virginia in January

Outdoors, we transplant nothing.

In the hoophouse, we fill gaps that occur in the beds. We replace spinach with spinach, brassicas with brassicas wherever possible. We use the Filler Greens which were sown October 10 and October 20 (brassicas such as senposai, Yukina savoy and the frilly mustards) and October 24 and November 9 (spinach). In December I mistakenly said that December 25 is our official last date for using the brassica fillers because there is not enough time for them to make worthwhile growth before they bolt. But I really meant January 25! Sorry!

  • Until January 25, fill gaps with Asian greens, spinach or lettuces as appropriate to match their neighbors.
  • From January 25 to February 20 fill all gaps everywhere with spinach transplants, except for places that will be sown in new crops in February.
  • From February 20, only fill gaps on the outer thirds of the beds, leaving the bed centers free for tomatoes, etc. in mid-March.

Other Cooking Greens Tasks in Central Virginia in January

We continue to harvest the hardier greens, and if (when) low temperatures are forecast, we might decide to clear the vulnerable crops and put them in the cooler.

See Cooking Greens for November for more details on winter-kill temperatures

During December we had two nights at 17°F (-8.5°C). The Koji are looking quite damaged. We grew more of this than we could eat before temperatures got too cold. Next year I hope for a return to the more cold-tolerant Yukina Savoy instead. We have not covered the spinach, because of issues with rowcover fibers getting in the food, and we’ll see how much production we get without rowcover. I’m expecting it to be a lot less, as spinach (like kale and lettuce) makes some growth whenever the temperature is 40°F (4.5°C) or more. That happens much more often under rowcover on sunny days than in the open. Savoyed spinach which we prefer) is hardier than smooth-leafed varieties. 10°F (-12°C) could kill the larger leaves and 5°F (-15°C) could kill it off entirely. This would be unfortunate as we expect to harvest a lot from out over-wintered spinach in the spring. Maybe temperatures won’t get that cold this winter, but I’m not holding my breath. Some spinach (Bloomsdale Long Standing, Bloomsdale Savoy, Olympia) is hardy down to 0°F (-18°C). We, however, have not been focused on growing the variety with the best absolute cold-tolerance.

Our chard is pretty much dead. The green is hardier than the multi-colored, which died a while back. Green chard is hardy to 12°F (-11°C), but ours is already weather-beaten. Because we have nice chard in the hoophouse, we no longer try to preserve the outdoor crop in winter.

I’m expecting January temperatures to bring the outdoor Koji and senposai to an end.

Spotting cabbage seedlings from a seed flat into a transplant flat.
Photo Wren Vile

Special Cooking Greens Topic for January: Lots of Planning!

We get our Crop Review, Seed Inventory and Seed Orders out of the way before the end of the year, then dive in during January to line everything else up for the next growing year. We use a lot of spreadsheets, and also maps and lists. First we prepare our new Seedlings Schedule, then our complex Fall Brassica Spreadsheet and Map, Field Planting Schedule, Hoophouse Schedule for March to September crops (those are not cooking greens!), and then our Raised Bed Plan and our monthly Garden Calendar.

The Seedlings Schedule Spreadsheet is most pressing, as we start greenhouse sowings in mid-January. Updating the spreadsheet from last year’s to create the new spreadsheet takes us three hours, plus proofreading and corrections. As we go, we make a list of questions or points to fix later, and we use highlighter on cells with unsure data to go back to. Our seedlings schedule has a column for the planned sowing date, one to write in when we actually do that sowing (in case it’s different), columns for the germination date, and the hoped-for transplant date, the vegetable, variety, how many row feet we want to plant, how many plants we will transplant in 100ft, and then a column with a calculation of how many plants we want to grow (allowing 20% extra on most crops). We will be spotting our transplants into flats of 40 plants, so next we calculate how many spotted flats we will need (simply the number of plants divided by 40). From that we calculate how many seed flats to sow. We reckon on getting 6 spotted flats from one seed flat, so again it’s a simple division. And we round up.

For crops that we sow in cell-packs (plug flats) we add another 20% to the Plants number. Lots of things can go wrong in January and February and we want to be sure to have enough plants. Also a lot of these early cell-packs are tomatoes for the hoophouse and we might want 15 different varieties.

All our spreadsheets have a Notes column, either with a pre-recorded reminder or hint, or with space to write in anything unusual or a different idea for next year. We check this and revise the sowing and transplanting dates accordingly.

Once we have the new spreadsheet set up, we get ready for the slow part of the job. One nice thing about spreadsheets is that you can sort the data each time you want a different perspective. We want to end up with a schedule in date order, but as far as feeding in the crop data, an alphabetical list by crop is much easier.

First we go through the current year’s Seed Order updating Varieties and Row Feet. Then we go through the Seed Order line by line, cross-checking to ensure that everything ordered gets sown (crops for transplanting only).

When we’re satisfied with that, we resort the data by transplant date, then by Vegetable, then Variety. We take the previous year’s Outdoor Planting Schedule (Field Planting Schedule) and revise the Seedlings Schedule accordingly.

Before we’re done, we check the highlighted cells and resolve any unresolved issues on our piece of paper. We check germinator shelves in use on any one day: We have space for 24 flats at once. Check the number of Speedlings in use at one time, we have 27. We refer to last year’s Seedlings Schedule for days to germination.

With all that work done, we can resort the data by Sowing date, then by Vegetable, then Variety. We proofread for sense before tidying up the formatting, and making sure all the columns fit on one sheet. We revise the instructions before we forget!

Hoophouse video interview, plus 2019 Round up of favorite topics and posts you missed

No-Till Growers and Josh Sattin collaborated to post this Hoophouse Tips video interview of me talking about our hoophouse:

 

After a Best Ever day on November 7, 2019, when 876 people viewed my website (4,855 that week), December has been quiet. It’s not a big gardening month for most of us, and the month is full of holidays. And then there’s the urge to hibernate.

Nonetheless, I have been reliably posting every week, and you might have accidentally missed something, while entertaining the visiting aunts and uncles, or rushing to get the carrots harvested, or something involving food and drink. Here’s a chance to  find the lost treasures!

December 24, I posted a Book Review: Grow Your Soil! by Diane Miessler

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Three potato forks to the left, four digging forks to the right.
Pam Dawling

On December 18, I posted Making Use of Greenhouse Space in Winter and Getting the Right Fork

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Purple ube grown in North Carolina by Yanna Fishman

December 10, did you miss Yanna Fisher’s splendid purple ube?

And Josh Sattin’s video interview with me? Legendary Farmer on a Legendary Commune  https://youtu.be/vLzFd4YP9dI

And Jesse Frost’s interview with me on his podcast No-Till Growers ?  You can listen to it here and it’s also on You Tube: https://www.youtube.com/watch?v=p75gRIl0Hzs


Reflect spinach in the open got damaged but not killed at -9F.
Photo Pam Dawling

On December 3, I posted Cooking Greens in December

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On November 26, I offered you a Book Review: Will Bonsall’s Essential Guide to Radical, Self-Reliant Gardening


My Top Six. no Seven,  posts of all time:

Winter-kill Temperatures  of Winter-hardy Vegetables 2016 with 23,776 views, peaking in November. Clearly lots of people want to know which crops will survive and which to hurry and harvest, or protect with rowcover.

Garlic scapes with 11,202 views. Garlic and sweet potatoes are the favorite crops on this site. Garlic scapes used to be under-appreciated and under-used. Not now!

Winter-kill Temperatures of Cold-Hardy Vegetables 2018 with 9,979, also peaking in November. My list gets updated each year as I learn new information. But the older ones come higher on internet searches.

Soil Tests and High Phosphorus Levels close behind at 9,503. High phosphorus is a worry for organic growers, especially those using lots of compost, as it can build up each year.

How to Deal with Green Potatoes at 8,613, with sustained interest through August, September and November. Obviously we are not the only growers with this problem, caused by light getting to the tubers.

Tokyo Bekana at 2,199 (who knew that was so popular?)

In 2019 other popular posts included Hunting Hornworms and the newer Winter-Kill Temperatures of Cold-Hardy Vegetables 2019. It takes a while for newer posts to gain on the older favorites.

Cooking Greens in November

A cabbage, with curled back leaf on the head, showing maturity.
Photo Bridget Aleshire

Cooking Greens to Harvest in Central Virginia in November

Beet greens – we get our last chance for greens as we harvest all our beets for storage. Sometimes the greens are in too poor shape to eat. Beets are hardy down to 15-20°F (–7 to –9.5°C) outside without rowcover.

There’s also cabbage, chard, Chinese cabbage (perhaps), collards, kale, komatsuna, senposai, , spinach, tatsoi, and Yukina savoy. Eat-All Greens harvests can continue, if you sowed some in September. When we sowed some on September 16, we got several harvests in November.

From the hoophouse we continue harvesting spinach, tatsoi thinnings and leaves, as well as leaves of Tokyo Bekana and Maruba Santoh. We can start to harvest chard, senposai, Yukina Savoy leaves and perhaps kale, although it is a slow grower.

At the end of November we keep a close eye on the Tokyo Bekana and Maruba Santoh, for signs of bolting. Normally these will bolt in December, so we harvest the whole plants that month. But we have sometimes needed to terminate the plants November 26 or so.

Cooking Greens to Sow in Central Virginia in November

Young spinach plants (and henbit) in our hoophouse in December.
Photo Pam Dawling

Outdoors

we sow spinach (for spring harvesting) in early November if we have not been able to do it already.  Hopefully we will have got this done during October. Here it’s too late for any more outdoor sowings till spring, although there will be garlic planting.

In the hoophouse

on November 9 we sow spinach #3 to fill any spinach casualties that happen during the winter, and “Frills“ #2 (mizuna, Ruby Streaks, Scarlet Frills, Golden Frills). This is one of our favorite winter crops to suppress nematodes. We sow tatsoi #2 on November 15. We could sow Eat-All Greens in hoophouse in November, but so far we haven’t tried that.

No Cooking Greens to Transplant in Central Virginia in November!

Other Cooking Greens Tasks in Central Virginia in November

While watching the temperature forecasts, we continue to harvest the hardier greens, such as chard, yukina savoy, collards, kale, spinach and tatsoi.

Pak Choy outdoors should be harvested before night temperatures of 25°F (–4°C) or covered with thick rowcover.
Photo Ethan Hirsh

As night temperatures drop, we clear some crops

In this order:

25°F (–4°C) Most broccoli, some cabbage, Chinese Napa cabbage, Maruba Santoh, mizuna, most pak choy, Tokyo Bekana.

22°F (–6°C): Bright Lights chard.

20°F (–7°C): Less-hardy beets, broccoli heads (some may be OK to 15°F/-9°C), Brussels sprouts, some cabbages (the insides may still be good even if the outer leaves are damaged),  cauliflower, most turnips.

15°F (–9.5°C): The more hardy beet varieties and their greens, some broccoli, some cabbage, red chard (green chard is hardy to 12°F (-11°C)),  Russian kales, rutabagas if not covered, turnip leaves, most covered turnips.

Each winter I update my Winter-kill Temperatures of Cold-Hardy Vegetables. This year I’m watching the Koji carefully, to get some good data.

Washing Cylindra beets for storage.
Photo Wren Vile

Killing temperatures outdoors

Here are some more numbers for killing temperatures outdoors (without rowcover unless otherwise stated). In my Cooking Greens in October post, I gave the Veggie Deaths in the  35°F (2°C) to 15°F (–9.5°C) range. Here’s the next installment, which I am prompted to post by the forecast 16°F (-9°C) here for the night of Friday November 8. This list only includes the cooking greens. Your results may vary!  Let me know!  Click the link above to see the complete list.

12°F (-11°C): Some beets (Cylindra,), some broccoli, Brussels sprouts, some cabbage (January King, Savoy types), most collards, covered rutabagas (swedes), some turnips (Purple Top).

10°F (-12°C): Covered beets, Purple Sprouting broccoli for spring harvest (too cold here for us to grow that), a few cabbages (Deadon), chard (green chard is hardier than multi-colored types), some collards (Morris Heading can survive at least one night at 10°F/-12°C), probably Komatsuna; Senposai leaves (the core of the plant may survive 8°F/-13°C), large leaves of savoyed spinach (more hardy than smooth-leafed varieties), Tatsoi, Yukina Savoy.

5°F (-15°C): some kale (Winterbor, Westland Winter), smaller leaves of savoyed spinach and broad leaf sorrel. Many of the Even’ Star Ice Bred greens varieties are hardy down to 6°F (-14°C).

0°F (-18°C): some collards (Blue Max, Winner), Even’ Star Ice-Bred Smooth Leaf  kale, some spinach (Bloomsdale Long Standing, Bloomsdale Savoy, Olympia).

 Reminder: The temperatures given are air temperatures that kill those outdoor unprotected crops.

Ruby chard.
Photo Kathryn Simmons

Overwintering chard

To keep chard in good condition overwinter, either cover with hoops and rowcover (in milder areas, Zone 6 or warmer), or else mulch heavily right over the top of the plant, after cutting off the leaves in early winter.

Covering spinach

Once the frost has killed the galinsoga we go ahead and put rowcover over the spinach beds. That happened this weekend (November 2 and 3) – we got temperatures of 27°F (–3°C) and 25°F (–4°C). Spinach will make growth whenever the temperature is 40°F (5°C) or more, which happens a lot more often under rowcover than exposed to the elements. We don’t want to provide rowcover for the galinsoga!

Weeding rowcovered spinach in winter.
Photo Wren Vile

Special Cooking Greens Topic for November: Seed Inventory

November is a good month for us to start our big winter planning process. For all the crops, not just cooking greens! The first step is the Seed Inventory, in preparation for ordering the right amounts of the right varieties of seeds for next year. We do ours fairly accurately, because we also use the process to fine tune the amount of seed  to buy for each row we plan to sow. Some growers simply buy plenty and throw away all the leftover seed each season, but for us the time spent paying attention to what we need is very worthwhile. See the Planning section in my book Sustainable Market Farming for step by step details on how we do it.

We use a spreadsheet and a cheap little digital scale (for the small amounts, up to 100g). Ours is an AWS-100. It’s not legal for trade, but we are not using it to weigh seeds for sale, just to give ourselves a good idea of what we have left. For large quantities, we use our business shipping scale.

We take a few seed buckets and the scale into a pleasant-temperature room, and take out a bundle of seed packets of a particular crop. First we weigh a packet at a time and write down the amount. The scale can be tared for the empty packet.

Seed Viability

Next we assess whether the seed will be viable next year. Storage conditions make a big difference, the best storage being cool, dark, dry and airtight. Make your own decisions based on how carefully you stored the seeds, the information on each packet about percentage germination when you bought it, and the economic importance to you of that particular crop.

We have a simplified chart:

  • Year of purchase only: parsnips, parsley, salsify, scorzonera and the even rarer sea kale;
  • 2 years: corn, peas and beans of all kinds, onions, chives, okra, dandelion and
    martynia;
  • 3 years: carrots, leeks, asparagus, turnips and rutabagas;
  • 4 years: spinach, peppers, chard, pumpkins, squash, watermelons, basil, artichokes and cardoons;
  • 5 years: most brassicas, beets, tomatoes, eggplant, cucumbers, muskmelons, celery, celeriac, lettuce, endive and chicory.

If the seed is still recent enough to grow well, we keep it. If it is too doubtful we “write it off” on the spreadsheet and consign the packet to a special “Old Seeds” bucket, which we keep for a year in case of mistakes or desperation!

This is the time we adjust the “seed rate” (seed/100′ or /30 m) column on our spreadsheet using our new information from our year.

After completing the inventory we have our annual Crop Review which we combine with popping garlic cloves for planting.

Popping garlic cloves in preparation for planting
Photo credit Southern Exposure Seed Exhcange

Hoophouse Sliding Doors, Vegetable Weevil Larvae – Seasonal Challenges!

September 6 sowing of tatsoi and our August 28 sown catch crop of Tokyo bekana. We harvested the last of this catch crop October 14 and sowed turnips, Photo Pam Dawling

October is the busiest month in our hoophouse! The bed prep, sowing and transplanting keeps us busy for 3 or 4 hours a day. Add in harvesting (peppers, radishes, salad crops) and hand-watering of new plants, and we’re there for a good half of each day. And then there are extra challenges. Yesterday, in tightening one of the strings that mark the bed edges, I managed to hammer a 6” sod staple right through the irrigation main line tubing, which was below soil level. I can hardly believe I did that! I even thought “Be careful not to stab the water pipe!” So I had to dig it up, find a coupler and fix it right away. Because at this time of year, we rely on the irrigation for all the new plants.

And the nights are getting colder. We intend to close the doors every night when the temperature will be below 50F (10C), and the windows if the temperatures will be below 45F (7C). We have been converting the doors at one end from hinged to sliding doors. They’re hanging on their tracks, but one door is jamming in the track, and we need more than a cursory look to fix the problem. So meanwhile, only 3 of the 4 doors close!

One of the new sliding doors on our hoophouse.
Photo Pam Dawling

Hoophouse Doors

My book The Year Round Hoophouse, has a chapter on making end walls, including doors and windows. Writing that helped me decide to change our east doors. Here’s an excerpt from that chapter:

 “For our 30′ (9.1 m) wide gothic hoophouse, we have a pair of hinged double 4′ x 8′ (1.2 x 2.4 m) doors at each end. Our doors open out and have to drag over the grass outside. We have found “rising butt” hinges to be helpful here. As the door opens, it rises on the curved base of the hinge, giving a little extra clearance above the ground. Each door fastens with a hook and eye to the wall when open (it will get windy!).  I recommend considering sliding doors, with the track and hardware on the inside, if the tunnel is wide enough for the track needed to carry the size of doors wanted. This avoids problems in many weathers: rampant grass-growing season, snow season, strong winds. Some people purchase storm doors and use those, but they are not very big. Anyone with basic carpentry skills can make simple door and window frames, as they will be covered both sides in lightweight plastic and not need to be extremely strong.”

View through the old hinged hoophouse doors in a previous December.
Photo Kathleen Slattery
Close up of a roller bracket attaching our hoophouse door to the track.
Photo Pam Dawling
  •  Matt Kleinhenz of the Ohio State University Vegetable Production Systems Laboratory, has a slide show of end wall designs High tunnel end wall and door types images,
  • ·        David Laferney of The Door Garden, in Building Greenhouse Doors,, 2008 has clear photos of hinged door construction for beginner carpenters.
  • ·        Hightunnels.org has various articles on construction, including a slideshow Images of High Tunnel Doors.
  • ·        For more to read, see M D Orzolek, High Tunnel Production Manual. See Chapter 3: High Tunnel Construction

Vegetable Weevil Larvae

A new Tokyo bekana transplant attacked by vegetable weevil larvae October 10
Photo Pam Dawling

Sometimes in the cool weather we have problems with this secretive pest chewing holes in brassica leaves at night. The larvae live in the soil and stay underground or deep in the heart of the plants during the day, so if your leaves are holey, but you can’t find any culprits, you can suspect vegetable weevil larvae. They especially like turnips, pak choy and the flavorful mustardy greens. We sprayed with Spinosad last Monday, then again on Friday, and this week (Monday and Tuesday) I’m not seeing any new holes.

Debbie Roos of Growing Small Farms wrote about this pest in “The Bok Choi Problem” which has good photos and a Description and Biology of the Vegetable Weevil

Vegetable weevil larvae in action. From Growing Small Farms
Photo Debbie Roos

 

Cooking Greens in October

 

Vates kale in the fall.
Photo Bridget Aleshire

Cooking Greens to Harvest in Central Virginia in October

Beet greens, broccoli, cauliflower, cabbage, chard, Chinese cabbage, collards, kale,  komatsuna, Maruba Santoh, pak choy, senposai, spinach, tatsoi, Tokyo Bekana turnip greens and Yukina savoy can be available here all month (and perhaps longer, depending on the temperature). OP Yukina Savoy seems more cold-hardy  and bolt-resistant than the hybrid Koji.

The new outdoor greens this month are tatsoi, kale, spinach, collards, and mizuna (if we have that outdoors).

Eat-All Greens harvests can start, if you sowed some last month. When we sowed some on September 16, we got two harvests in October and several in November.

From the hoophouse we start to harvest spinach, tatsoi, and leaves of Tokyo bekana.

Cooking Greens to Sow in Central Virginia in October

This month we finish sowing spinach and kale for overwintering outdoors (10/30 is our last chance). No more outdoor sowings until spring!

“Filler Greens”

Filler greens: short rows of Tokyo bekana, Yukina Savoy and senposai used to fill gaps in the winter hoophouse.
Photo Pam Dawling

On October 10, we sow Brassica fillers #1. These are short rows of senposai, Tokyo bekana, Yukina Savoy, Maruba Santoh,  to use to fill gaps later during the winter as soon as they occur. We simply dig them up, replant where needed and water well. Alternatively you could keep some plug flats of these plants handy. Bare-root transplanting is much easier than many fear.

During December we use the “Filler” greens plants to replace casualties and harvested heads of Tokyo bekana, Maruba Santoh, Chinese cabbage, Pak choy, Yukina Savoy and tatsoi daily. We stop filling gaps in these early harvest crops on December 25, as they will bolt in the hoophouse conditions in January at the latest.

We continue to fill gaps elsewhere with senposai until January 25. Asian greens don’t make good growth before bolting if transplanted after January 25. From January 25 to February 20 we fill all gaps everywhere with spinach transplants

Hoophouse Bed preparation and Planting

In the hoophouse we have a lot of bed preparation (all the beds except the Early Bed which we plant in September), as well as transplanting and sowing.

On October 14, we sow turnips #1: Red Round (1 row on North), Hakurei (2 rows South). Oasis, White Egg.

On October 20, we sow Filler Greens #2.

By October 23, we clear and prepare two more beds and sow spinach #2; tatsoi #2, turnips #2, chard #2 and perhaps Frills (Frilly Mustards) #1.5.

Brassica (Mustard) Salad Mix

Interesting mustard mixes are sold for salad mixes. We often mix our own Brassica Salad Mix from leftover random brassica seeds. For a single cut, almost all brassicas are suitable – just avoid turnips and radishes with prickly leaves! We sow between October 2 and November 14 for harvests during the winter, and from December 4 to February 12 for March and early April harvests.

We could, but so far we haven’t, sow Eat-All Greens in hoophouse in October.

Catch crops

Useful if a crop fails, or you have an empty space. Don’t delay, as rates of growth slow down as the temperatures and daylight decrease. Don’t expect much from sowings during the Persephone Days (less than 10 hours daylight).

Tokyo bekana is a quick-growing Asian green, for cooking or salads.
Photo Twin oaks Community

This year we grew an early catch crop of Tokyo bekana when we realized we had space that wouldn’t be needed till mid-October (for turnips). We direct sowed it August 28, weeded and thinned to 1” (2.5 cm) on September 5; weeded and thinned to 3” (7.5 cm) on September 16, using the small plants for salad. We need to clear this crop by the middle of October to sow the turnips, and the Tokyo bekana has got to a fine size.

  • Ready in 30–35 days in fall, longer in winter: brassica salad mixes, spinach, chard, salad greens (lettuce, endives, chicories), winter purslane., kale, arugula, radishes (the fast small ones and the larger winter ones), many Asian greens: Komatsuna, Maruba Santoh, mizuna, frilly mustards, Senposai, tatsoi, Tokyo Bekana and Yukina Savoy.
  • Ready in 35–45 days in fall: corn salad, land cress, sorrel, parsley and chervil.
  • Ready in 60 days in fall: beets, collards, kohlrabi, turnips

Cooking Greens to Transplant in Central Virginia in October

September sown White Russian kale (transplanted in October).
Photo Wren Vile

In our hoophouse in early October, we transplant Tokyo Bekana, Chinese cabbage, Pak choy, Yukina savoy #1,  using plants which we sowed outside under insect netting.

By October 13, we transplant chard #1, Frills #1, and Red and White Russian kales, from our outdoor nursery seedbed.

By October 21, we clear and prepare another bed and transplant 1/2 bed kale, plus Yukina Savoy, and frilly mustards. (This is our favorite crop selection to suppress nematodes),

By October 23, we clear and prepare two more beds and transplant senposai and Yukina Savoy #2 from the outdoor nursery bed.

Other Cooking Greens Tasks in Central Virginia in October

October is our month to weed and thin the fall crops in the outdoor raised beds, especially spinach and kale. We thin kale to 12” (30 cm); perhaps more space would be better, although Vates is a dwarf variety.

We put rowcover over any beds of pak choy, Chinese cabbage or Tokyo bekana we have that year. Later we weed (again!) and cover the spinach for faster growth, but leave the kale uncovered after a bad experience of Vates kale with rowcover fibers mixed in. The cooks didn’t love us!

Galinsoga dies with the frost.
Photo Wren Vile

We prefer to wait to cover spinach after frosts kill the galinsoga. As well as raised beds, we plant spinach in our cold frames, making good use of the space until the frames are needed in spring for hardening off transplants.

We roll, label and store drip tape from the fall broccoli and cabbage

Special Cooking Greens Topic for October: Get Soil Tests; Be Ready for Cold Nights.

October is a good month to do soil tests, when the soil is not too wet, and the soil temperatures are still warm (the soil life is active).

Weather Forecasting

We use Wunderground, but subtract 5F° from their forecast night lows for our nearest town, and mentally downgrade the chance of rain by 10%, as rain often passes us by as it scoots along the river valley north of us.

See Weatherspark.com for the typical ranges of weather in your area:

Savoy cabbage with frost.
Photo Lori Katz

Predicting Frost

Frost is more likely at Twin Oaks if:

  • The date is after 10/14 or before 4/30 (our average first and last frost dates).
  • The Wunderground forecast low for Louisa Northside is 37°F (3°C) or less.
  • The daytime high temperature was less than 70°F (21°C).
  • The temperature at sunset is less than 50°F (10°C).
  • The sky is clear.
  • The soil is dry and cool.
  • The moon is full or new (maybe to do with tides and gravity?).
  • If temperatures are falling fast, the wind is from NW and the sky is clear, then polar air may be moving in, and we’ll get a hard freeze.
  • The dew point forecast is low, close to freezing. Frost is unlikely if the dew point is 43°F or more.

Watch for cold night temperatures and decide which crops to harvest, which to cover, which to abandon:

In a double-layer hoophouse (8F/5C warmer than outside) plants can survive 14F/8C colder than outside, without extra rowcover; with thick rowcover (1.25 ozTypar/Xavan) plants can survive at least 21F/12C colder than outside.

The hoophouse winter crops are an important part of feeding ourselves year-round

Each winter I update my Winter-kill Temperatures of Cold-Hardy Vegetables.

Here are some early winter numbers for killing temperatures outdoors (without rowcover unless otherwise stated). Your results may vary!  Let me know!        

35°F (2°C): Basil.

32°F (0°C): Beans, cucumbers, eggplant, melons, okra, peppers, tomatoes.

27°F (–3°C): Many cabbage, Sugarloaf chicory.

25°F (–4°C): Some cabbage, chervil, chicory roots for chicons and hearts, Chinese Napa cabbage, dill, endive, some fava beans, annual fennel, some Asian greens (Maruba Santoh, mizuna, most pak choy, Tokyo Bekana), some onion scallions (many varieties are hardier), radicchio.

22°F (–6°C): Some arugula (some varieties are hardier), Bright Lights chard, large leaves of lettuce (protected hearts and small plants will survive colder temperatures), rhubarb stems.

20°F (–7°C): Some beets, broccoli heads (some may be OK to 15°F/-9°C), Brussels sprouts, some cabbages (the insides may still be good even if the outer leaves are damaged), celeriac, celtuce (stem lettuce), some head lettuce, some mustards/Asian greens, flat leaf parsley (curly parsley is hardier), radishes, most turnips.

15°F (–9.5°C): Some beets, beet greens, some broccoli, some cabbage, rowcovered celery, red chard (green chard is hardy to 12°F (-11°C)), cilantro, endive, some fava beans, Russian kales, kohlrabi, some lettuce, especially medium-sized plants with 4-10 leaves, curly parsley, rutabagas if not covered, broad leaf sorrel, turnip leaves, most covered turnips, winter cress.

Frosted daikon radish.
Photo Bridget Aleshire

Frilly Mustards in our Winter Hoophouse

 

Hoophouse frilly mustard, mizuna and lettuce mix in our hoophouse in December.
Photo by Kathleen Slattery

I have written before about our love of Ruby Streaks, a beautiful dark red frilly mustard. We also like Golden Frills and Scarlet Frills. We like Mizuna too. It was our “gateway frilly mustard”!

Green mizuna in our hoophouse in November.
Photo Pam Dawling

Mizuna – the Gateway Mustard.

Mizuna is a very mild flavored crop, with thin juicy white stems and green ferny leaves which add loft in salad mixes. (“Loft” is the word for the “puffiness” of frilled salad crops, helping them occupy space and not collapse in the bottom of the bag or bowl like wet green corn flakes.) This tolerant crop is very easy to grow, tolerates cold wet soil, and variable weather. It is fairly heat tolerant (well, warm tolerant), and cold tolerant to 25°F (-4°C).

We used to just grow just one planting, sowing it outdoors September 24, transplanting it into our hoophouse October 22. It regrows vigorously after cutting and we harvest leaves from November 27 to January 25 or even to March 7, when it becomes a mass of small yellow flowers (edible!). In the winter, once the plant gets bigger and bushier, we switch from harvesting individual leaves to a method we call the “half-buzz-cut.” We gather the leaves on one side of the plant and cut them with scissors about an inch above the soil. Then we chop them into our salad mix harvest bucket. The plants look odd with half their leaves still full-size and half shorn, but this method seems to help the plant regrow quicker. The big leaves can photosynthesize and feed the regrowing leaves.

Next we tried Purple Mizuna, but we were disappointed with the weak color and a constitution less-robust than green mizuna.

Ruby Streaks and other Frilly Mustards

After a few years of growing mizuna, we discovered Ruby Streaks. It has a much stronger color, and I admit, a much stronger flavor. Our diners don’t generally like pungent greens, but this one, cut small and mixed with other salad greens, gained wide approval. We have moved on to include Golden Frills and Scarlet Frills, and for a while Red Rain. We find the Scarlet Frills and Golden Frills bolt (go to seed) later than Ruby Streaks and Mizuna.

Ruby Streaks beside green mizuna.
Credit Ethan Hirsh

Adding a Second Sowing

We added a second sowing, this one direct-sown in the hoophouse, on October 30, and the next year shifted the date to November 9. These direct-sown mustards can be used for baby salads after only 21 days (when thinning the rows, for instance). Thin to 8″–12″ (20–30 cm) apart, to grow to maturity in 40 days. We sow mizuna and the spicier mustards at the same time, usually 6 rows to a 4’ (1.2 m) wide bed, maybe a total row length of 50’ (15 m). This sowing gives us harvests from February 26 to March 24, several weeks later than the September 24 sowing.

Golden Frills and Ruby Streaks in our hoophouse.
Photo Pam Dawling

Fighting Nematodes

When we learned our hoophouse soil had nematodes some years ago, we searched for resistant crops and were happy to learn that Brassica juncea greens were resistant. Although mizuna is not B. juncea, the more pungent frilly mustards are, so we focused on growing those, and ignored mizuna for several years.

Adding a Third Sowing

We were looking for a late winter nematode-resistant crop to follow our Koji, which I think bolts up to a month earlier than my long-time favorite Yukina Savoy. We tried the frilly mustards, sown February 1, and they were very successful. We got harvests from March 24 to April 23, a very worthwhile month of greens! I like greens that are harvestable in March and April, because this is really our Hungry Gap, the time when the stored crops are running out and the outdoor spring-planted ones haven’t really got producing much yet. I’m a bit suspicious of our record-keeping on the April 23 date – I suspect it was really over before that. It seems unlikely that this sowing lasts 30 days when the second one only lasts 26 days.

 

By trial and error, we found that our last worthwhile hoophouse sowing date for frilly mustards is February 12.

Bye bye mizuna! Bolting mizuna (our third planting) in our hoophouse in mid-April.
Photo Pam Dawling

Trying a Fourth Sowing

As part of a renewed effort to manage the nematodes, last year we added in a fourth sowing, on October 30. I haven’t got any records for that harvest to hand. I do remember though, that we had about as much “Frills” (as we now call them) as we could eat. We planted 30’ (9 m) in the first sowing, 50’ (15 m) in the new extra planting, 48” (14 m) in the November 9 sowing, and a whopping 120’ (36 m) in the February 1 sowing.

Dragonfly Swarms, Mother Earth News, and Heritage Harvest Festival

Dragonfly photo courtesy Staunton News Leader

Swarms of dragonflies are popping up  in Virginia

Leanna Smith, in the Staunton News Leader reported that meteorologists in Ohio had spotted something unexpected on the radar on September 10 — a swarm of migrating dragonflies. The radar maps are impressive! The Common Green Darner dragonflies (Anax junius) were reported swarming in Maryland (Sep 11 evening), New Jersey (Sep 12 nighttime) and Virginia (Sep 11 and Sep 12 morning).

She reported that it is common for dragonflies, especially green darner dragonflies, to migrate south in the fall to find warmer weather, but the swarming is unusual. Ohio State University Entomology Professor Norman Johnson spoke to CNN and said that weather conditions can cause the traveling insects to swarm. In 2018, the Washington Post reported that the migration of green darner is typically unremarkable because the insects rarely travel in packs. Although much is still unknown about the migration of dragonflies, we do know that they are very sensitive to temperature. “Climate warming could really disrupt the presence of this migration,” Colin Studds, an animal ecologist at the University of Maryland Baltimore County, told the Post.

It is fairly common for radar to pick up biological movement, especially around sunrise and sunset when warmer air above us can bend the radar beam toward lower elevations where the movement is occurring, according to meteorologist Chris Michaels.

On September 10, the National Weather Service of Cleveland, Ohio tweeted about the new development.

Clouds of dragonflies.
Photo NWS Cleveland @NWSCLE

Ohio State University entomologist Norman Johnson said the dragonflies are likely Green Darners, which migrate south in the fall. “The insects don’t usually travel in flocks,” he told CNN, “but local weather conditions can cause them to bunch up.” “The big swarms have been recorded a lot over the years, but they’re not regular,” Johnson said.

Details of dragonfly migration are still unclear; researchers have found the winged creatures travel an average of 8 miles per day, but can fly as far as 86 miles.

For up to the minute sightings, see the Migratory Dragonfly Partnership Search page

TOWARD THE UNKNOWN  A common green darner can migrate hundreds of kilometers each year. A new study reveals details of the insects’ annual migration for the first time. Photo Mark Chappell

Susan Milius in Science News reports that Green Darner dragonflies migrate a bit like monarch butterflies, with each annual migratory loop taking multiple generations to complete.

Ecologist Michael Hallworth and colleagues wrote the migration of the common green darner, described December 19, 2018 in Biology Letters, using data on forms of hydrogen in the insects’ wings, plus records of first arrivals spotted by citizen scientists. Citation https://doi.org/10.6084/m9.figshare.c.4320911.v2

“A first generation of insects emerges in the southern United States, Mexico and the Caribbean from about February to May and migrates north. Some of those Green Darners reach New England and the upper Midwest as early as March, says Hallworth, of the Smithsonian Migratory Bird Center headquartered in Washington, DC.

Those spring migrant darners lay eggs in ponds and other quiet waters in the north and eventually die in the region. This second generation migrates south from about July until late October, though they have never seen where they’re heading. Some of these darners fly south in the same year their parents arrived and some the next year, after overwintering as nymphs.

A third generation emerges around November and lives entirely in the south during winter. It’s their offspring that start the cycle again by swarming northward as temperatures warm in the spring. With a wingspan as wide as a hand, they devote their whole lives to flying hundreds of kilometers to repeat a journey their great-grandparents made.

Tracking devices that let researchers record animals’ movements for more than a week or two haven’t been miniaturized enough to help. The smallest still weigh about 0.3 grams, which would just about double a darner’s weight, Hallworth says. So researchers turned to chemical clues in darner tissues. Conservation biologist and study coauthor Kent McFarland succeeded at the delicate diplomacy of persuading museums to break off a pinhead-sized wing tip fragment from specimens spanning 140 years.

Researchers checked 800 museum and live-caught specimens for the proportion of a rare heavy form of hydrogen that occurs naturally. Dragonfly wings pick up their particular mix of hydrogen forms from the water where the aquatic youngsters grow up. Scientists have noticed that a form called hydrogen-2 grows rarer along a gradient from south to north in North America. Looking at a particular wing in the analysis, “I can’t give you a zip code” for a darner, Hallworth says. But he can tell the native southerners from Yankees.

An adult darner, regardless of where it was born, is “a green piece of lightning,” says McFarland, of the Vermont Center for Ecostudies in White River Junction. Darners maneuver fast enough to snap insect prey out of the air around ponds across North America. The front of an adult’s large head is “all eye,” he says, and trying to catch samples for the study was “like hitting a knuckleball.”

Although the darners’ north-south migration story is similar to that of monarch butterflies (Danaus plexippus), there are differences, says evolutionary biologist Hugh Dingle of the University of California, Davis, who has long studied Monarchs, which move northward in the spring in successive generations, instead of one generation sweeping all the way north.

Also, Dingle says, pockets of monarchs can buck the overall scheme. Research suggests that some of the monarchs in the upper Midwest do a whole round trip migration in a single generation. As researchers discover more details about green darners, he predicts, the current basic migration scheme will turn out to have its quirky exceptions, too.”

MASS MIGRATION

At least three generations make up the annual migration of common green darner dragonflies. The first generation emerges in the southern United States, Mexico and the Caribbean starting around February and flies north. There, those insects lay eggs and die, giving rise to second generation that migrates south until late October. (Some in that second generation don’t fly south until the next year, after overwintering as nymphs.) A third generation, hatched in the south, overwinters there before laying eggs that will start the entire process over again. These maps show the emergence origins of adult insects (gray is zero; red is many) captured at sampling locations (black dots).

Diagram by Matthew Dodder, M.T. Hallworth et al/Biology Letters 2018

Geek.com reports that this isn’t the first insect invasion of 2019. In June, the National Weather Service’s radar in San Diego picked up a giant crush of ladybugs about 80 miles across in each direction, over southern California. On June 27, residents of northeastern Ohio found themselves dealing with invasive mayflies, which covered cars, houses, and lampposts across Cleveland, Sandusky, and other areas.

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Mother Earth News Fair

I had a great time at the Mother Earth News Fair at Seven Springs, Pennsylvania. My first workshop, Lettuce Year Round, was on Friday lunchtime and attendees were still arriving. For those who wanted to hear all about it, but missed it, here is the slideshow:

And here is the extended version of Hoophouse Cool Season Crops. It has a lot of bonus material compared to the short workshop I gave last weekend.

Note that all the offers of pdfs of my books to download are scams and nothing to do with me! I cannot stop people posting them. It’s almost enough to stop me posting my slideshows, but I know people appreciate another chance to see the slides.

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Heritage Harvest Festival

This coming weekend, Saturday September 21, I’ll be presenting Winter Gardening: No Tech to High Tech with Ira Wallace at the Heritage Harvest Festival at Monticello in Charlottesville, VA. Ira will talk about outdoor winter gardening, and I’ll talk about hoophouse growing (which isn’t really that high tech!) It’s Saturday, Sept. 21 at 10:30am in the Heritage Tent. Here’s the LINK. The workshop is for gardeners to learn tips on growing cold-hardy vegetables (and not just kale!) out in the open and with varying degrees of protection from rowcovers, low tunnels, coldframes and hoophouses.

Read more about the Heritage Harvest Festival here

Buy tickets in advance here

Weeding rowcovered spinach in winter.
Photo Wren Vile

September in the hoophouse: sowing spinach, replacing bubble foil insulation, removing shadecloth

Two jars of sprouted spinach seeds and grits to prevent the damp seeds clumping.
Photo Pam Dawling

Sowing Spinach

We sow our first hoophouse spinach in the ground around September 7. Because it’s too hot in the hoophouse at this time for spinach seed to germinate, we pre-sprout the seed for a week in the fridge before sowing. This is very easy, much easier than growing beansprouts!

We measure out the amount of seed we’ll need and soak it overnight in a jar of water. We use 1oz (28 g) of seed per 90ft (27.4 m) row. We use a cup measure or a tablespoon that we keep in the spinach seed bucket. 7T = ½ cup. 1T=15 ml. It’s very roughly ½ cup per row. We use Mason jars and replace the flat metal lid with a piece of screen of some kind, metal or plastic, with holes smaller than spinach seeds. The Mason jar lid band holds this in place.

In the morning we drain off the excess water, and set the jar in the fridge on its side. Once a day we rotate the jar to even out the moisture and therefore hopefully the rate of growth of the shoots. After about a week the seeds have grown a short white root 1/8” (3 mm) long and are ready to sow.

Spinach seedlings from pre-sprouted seed in the hoophouse in September.
Photo Pam Dawling

When there is extra moisture with the seeds they can tend to clump together. One solution to this problem is to mix in a dry inert material like corn grits, as in the first photo, to make the seeds easier to sow individually. This year I tried a different approach. I spread out a scrap of rowcover on the ground and spread the seeds out on that to dry the surfaces. This made the seeds easy to sow, but I noticed that several white rootlets were left behind on the rowcover. I don’t know if the rowcover Velcro effect caused this or if it was a higher rate of damage than the grits treatment. It wasn’t a significant amount.

Replacing bubble foil

Beyond time to replace this torn and crumbling bubble foil insulation.
Photo Pam Dawling

We have a 3 ft (1 m) length of a foil and bubble-plastic roll material along the base of the north wall in our hoophouse. The north side is the coldest, and not a lot of direct light comes in there, that low down, so we decided to insulate from radiation losses and also get some light reflection back there. I think it works well, although I have not measured anything to see if my impressions are backed up by reality! We put the hoophouse up in 2003 and we have replaced this “bubble foil” once since. Definitely we left it too long since we last changed it. As well as big rips, we had micro-crumbs of plastic flaking off. Not what we want in our food!!

An office staple remover is the perfect tool for removing the batten tape (old driptape).
Photo Pam Dawling

I pulled off the old stuff, using an office staple remover to extract the old staples. I reused the scrap driptape we had been using as batten tape (still years of life left for it in that role!) My approach to agricultural plastics is to buy the most durable and treat them gently to make them last as long as possible. We had two partial rolls of the bubble foil material in the shed, so I used those, but found myself 14 ft (4 m) short, so we had to buy some more. I don’t know about durability, but the Reflectix product was the sturdiest at the start. How long would this stuff normally last? Two changes in 2003-2019 = 16 years. 8 years is too long! 6 or 7 seems like it might be OK. Ask me in 2025!

A quick crop of Tokyo bekana Asian greens for salad, in front of the new bubble foil.
Photo Pam Dawling

Removing the shadecloth

The 15 year-old shadecloth on our hoophouse is still serving us every summer.
Photo Pam Dawling

In the summer we cover our hoophouse with a large sheet of shadecloth. We pack it away in the second week of September. (It helps if the first bed of winter crops (planted September 6-7) has had a chance to germinate before we make it hotter in there by pulling off the shadecloth.) Our shadecloth is 50% knitted polyethylene. I think 45% would be better than 50%, next time we buy. And I think buying 100 ft (30 m) would be better than just the 96 ft (29 m) length of the hoophouse. See the way the shadecloth pulls away from the ends in the photo.

Our hoophouse in 2008 when the shadecloth was in better condition.
Photo Pam Dawling

We are still using the shadecloth we bought in 2004, 15 years later. It has a few mouse holes that happened in storage, and the fabric is starting to lose its strength and rip. We used to fix  snap-on grommets to the center-line of the shadecloth at the ends and tie with ropes onto the end wall structure. But nowadays the shadecloth is too weak to withstand the firm pull we need to give to get those ends in place. So we get a hot spot at each end of the hoophouse. We’ll need to buy new shadecloth in the next couple of years. Probably we can cut the old piece up into 7 ft (2 m) strips to use over beds of lettuce outdoors. It won’t need much tensile strength for that task.

We use snap-on grommets, big hooks in the baseboard and a long piece of rope, to hold the shadecloth along each long side of the hoophouse.
Photo Pam Dawling

Potato Research, Mother Earth News Fair PA and Heritage Harvest Festival

Crates of potatoes in our root cellar.
Photo Nina Gentle

Potato Research on Harvest and Storage

Last week I mentioned that while researching potato yield figures, I found an interesting publication, The Potato Association of America, Commercial Potato Production in North America 2010. I’ve been reading that and learning more about potatoes. Here I’m going to focus on harvest and storage, because that’s the bit we’re currently challenged by. I also learned more about planting in hot weather, but that’s for another time.

Potato harvest.
Photo Nina Gentle

In England we planted in spring and harvested in October, waiting for the frost to kill the vines. In Virginia we plant in March and June, harvesting in July and October. We have grown Red Pontiac, Yukon Gold and Kennebec here, mostly. They all seem to be determinate varieties. I only just learned there are determinate (varieties with naturally self-limiting growth, generally “early” varieties) and indeterminate varieties (such as “Russet Nugget,” “Nicola,” “German Butterball” and “Elba”). The distinction is explained in Potato Bag Gardening. Growers using towers, grow bags, and cage systems want indeterminate potatoes, which continue to produce more layers of tubers on the stems as they are progressively covered with more soil. Growers wanting a fast reliable crop in the field mostly choose determinate types, which grow as a bush, then flower and die. The Wild Woolly Web does seem to have some contradictory statements about which varieties are determinate and which indeterminate, and some dedicated container growers make assertions not supported by experienced commercial growers. So Reader Beware! I trust Extension and here’s a link to their Ask an Expert page on potato types, and the University of Maryland Extension Home and Garden Info Center Potatoes.

June-planted potatoes in early September
Photo Kathryn Simmons

Whether the vines die naturally at the end of their lifespan, or they die of disease, or the frost kills them, or you kill them yourself by mowing or flaming, the potatoes will store better if you then wait 2-3 weeks before harvesting. The potato skins thicken up (becoming more resistant to scrapes and bruises) and the potatoes become higher in dry matter. Harvesting is easier if the vines are well dead. We generally bush-hog ours. Decades ago, in England, we had late blight in the middle of the season, and we cut the tops off and made a very smoky bonfire. (I wouldn’t participate in that much air pollution nowadays!) After waiting for a couple of weeks for the late blight spores to die, we dug the potatoes. The idea was to prevent spores getting on the tubers. As I remember, it all worked out OK.

If at all possible, harvest when the soil moisture is 60-80% of field capacity. Not too dry, not too wet. This reduces damage from scraping. If using a digger, don’t set it digging too deep, or too much soil will be damped on the harvested potatoes.

Tuber temperature will also impact bruise and rot susceptibility. Ideally soil temperature will be 45-65F (7-18C).  Because soil temperature lags 3-4 hours behind air temperature rise each day, in cold weather, try to harvest around 6 pm or a bit later. In hot weather, harvest in the morning.

When freshly harvested, potatoes are tender, breathing things. Avoid bruising, which is damage that does not break the skin, by not dropping potatoes more than 6” (15 cm), or throwing them towards a container. Don’t bang them to knock off extra soil.

When harvesting in summer, we stack the crates of potatoes under a big tree overnight to lose some of the field heat before moving them to the root cellar early next morning. Potatoes you take from storage can be no better than the quality of the potatoes you put into storage!

The first part of the storage period is the curing. The potatoes are still actively respiring, so they need a good oxygen supply. Failure to ventilate the cellar enough can lead to Black-heart, where the inner tissue of the potatoes dies and turns black. During the curing period, the skins further toughen up, and cut surfaces and superficial wounds heal over, enabling long term storage. The temperature should be as close to 50-58F (10-14.4C) as you can get. The lower end of the range is best for fresh eating (as opposed to junk food manufacture). Hotter temperatures will promote more rot, and age the potatoes faster, leading to early sprouting. Relative humidity should be 90%, but not 100%! If there is too much condensation, use a fan and open the cellar doors, when temperatures are closest to the goal. Curing takes 10-14 days.

Sorting potatoes .
Photo Wren Vile

We find that a single thorough sorting after 14 days can remove almost all of the storage problems that are going to happen. Not sorting at this point lets rots spread.

After the curing period, the potatoes become more dormant and do not respire so actively. They don’t need as many air changes as during curing, but if the cellar is too warm, you will need to aerate more. The temperature during the storage period should be 40-50F (4.4-10C), and closer to the lower end of the range is best. Constant temperatures or a steady decline is the goal, not dramatic fluctuations. Humidity should still be 90-95%, to keep weight loss to a minimum.

Potatoes have a natural dormancy of 60-130 days (depending on the storage temperature). After that period, they will start to sprout. Some plant extracts, including clove oil, can add 20-30 days storage, and will then need to be reapplied. I do not know anything about this myself, and do wonder how you remove the clove flavor from the potatoes!

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Speaking Events

I have two speaking events coming up in September
Mother Earth News Fair

2019 Mother Earth News Fair Pennsylvania.

September Friday 13- Sunday 15, 2019
Location: Seven Springs Mountain Resort, 777 Waterwheel Dr., Seven Springs, Pa. 15622

I am giving two 60 min workshops

Hoophouse winter lettuce: Green Forest, and Red Salad Bowl, two of our fifteen varieties.
Photo Wren Vile

Lettuce Year-Round on Friday 9/13 12.30-1.30 pm at the Grit Stage

This presentation includes techniques to extend the lettuce season using row covers, cold frames, and hoop houses to provide lettuce harvests in every month of the year. The workshop includes a look at varieties for spring, summer, fall, and winter. Pam Dawling considers the pros and cons of head lettuce, leaf lettuce, baby lettuce mix, and the newer multileaf types. She also provides information on scheduling and growing conditions, including how to persuade lettuce to germinate when it’s too hot.

Cool Season Hoophouse Crops on Saturday 9/14 3.30-4.30 pm at the Building and Energy Stage

Learn how to fill your hoop house with productive food crops in the cool seasons. Pam Dawling discusses suitable crops, cold-hardiness, selecting crops, calculating how much to harvest and how much to plant, crop rotation, mapping, scheduling, seasonal transitions, succession planting, interplanting, and follow-on cropping.

Book-signing at the Bookstore Saturday 4.30-5 pm. Buy new books at the Bookstore and bring your grubby used copies to be signed too!

Demos at New Society Publishers booth, of tomato string-weaving and wigglewire system for fastening hoophouse plastic to framework
Friday 3 -3.30 pm, 4.30-5 pm; Saturday 10-11 am, 1.30-2.30 pm; Sunday 9-10 am. 1-2 pm, 3.30-4 pm

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Heritage Harvest Festival, Monticello, Charlottesville, VA

September Friday and Saturday 21-22, 2019
Buy tickets online
Workshop with Ira Wallace
10:30 – 11:30 am Saturday in the Heritage Tent

Winter Gardening: No Tech to High Tech 

Learn tips on growing cold-hardy vegetables (not only kale!) out in the open and with varying degrees of protection from rowcovers, low tunnels, coldframes and hoophouses (high tunnels). We’ll consider crop choices, planting dates and harvesting so there’s always something to eat for everyone from winter market gardeners to small backyard growers. We’ll explain ways to maximize production with succession planting and follow-on cropping.

 No extra fee for the workshop, included with the price of general admission

Booksigning: SATURDAY, SEPT. 21st, 11:45am – 12:15pm, MONTICELLO SHOP TENT (WEST LAWN). Buy new books at the Bookstore and bring your grubby used copies to be signed too!

December view in our hoophouse, showing lettuce mix and turnips.
Photo Wren Vile

Modern Homesteading Interview, Things I’ve Changed My Mind On

Hoophouse squash, tomatoes, and cucumbers.
Photo Alexis Yamashito

In April I did a pleasant phone interview with Harold Thornbro of the Modern Homesteading Podcast  about how year round gardening in a hoophouse can increase yields and the quality of vegetables and extend the growing season.

You can listen to it here:

https://www.stitcher.com/podcast/modern-homesteading-podcast/e/60326060?autoplay=true

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The rest of this post is about the agricultural things I’ve changed my mind on in recent years.

Sowing Leeks
Leek seedlings growing in an outdoor nursery bed.
Photo Kathryn Simmons

The first one that comes to mind is where and how to sow leeks. In Sustainable Market Farming I describe sowing leeks in outdoor nursery seedbeds. We grow leeks for eating from October to March, so even though leeks grow very slowly and need 12 weeks to transplant size, we don’t need to sow them super early in the year. Also because they are so cold-hardy, they don’t need greenhouse conditions. To save greenhouse space, and the bother of watering so many flats, we took to sowing them outdoors. To make this work, you do need weed-free beds. Leeks compete poorly with weeds. Sometimes things went wrong. One year someone decided to “seed-bomb” the fresh bed with poppy seeds. Weeding those tiny leek seedlings was torture! Another time, an overenthusiastic worker ran our new exciting wheel hoe too far onto the bed and eradicated part of a row.

Leek seedlings in flats in April.
Photo Pam Dawling

One year the leek seedling bed wasn’t ready in time to sow, and we sowed rows of seeds in a coldframe, after removing the winter spinach (or maybe we were still growing lettuce in the coldframes then.) This worked well. The next year we tried sowing the seeds in 4” (10cm) deep flats, and putting the flats into the coldframes right away (rather than germinating them in the greenhouse). Still no wasted greenhouse space! On very cold nights, we cover the coldframes, so it was a bit warmer than if we’d just sowed directly into an outdoor bed. The plants grew a bit quicker and we realized we didn’t need to start so early. They were easier to take to the field in the flats, compared to digging up the starts and carrying them in little buckets with water. We had reduced losses of seedlings, so we reduced the amount of seed sown in future years. It’s an easier system, with a more satisfying success rate.

Sunnhemp as a Cover Crop
Sunnhemp cover crop at Nourishing Acres Farm, NC.
Photo Pam Dawling

 Sunnhemp (Crotalaria juncea) is a warm weather leguminous cover crop that I’ve been admiring at various farms in the Southeast in recent years. I’ve been thinking it would be valuable ion our hoophouse and in our gardens. It fights root knot nematodes! I mentioned it recently at a crew meeting, only to be reminded that I previously spoke against growing it as the seed is poisonous! I’d completely forgotten my earlier opinion!

This summer cover crop can grow to 6’ (2m) in 60 days. It thrives in heat, tolerates drought, fixes nitrogen, suppresses nematodes, makes deep roots that pull nutrients from deep in the soil, and it dies with frost. It sounds fantastic, I really want to try it!  It looks a bit like small sunflowers, and according to Southern Exposure Seed Exchange  it  won’t make mature seed above 28 degrees N latitude , so won’t become a self-sowing invasive  in Virginia. Sow in rows 2’-3’ (0.6-1m) apart. If it gets too big, mow when plants reach 5’-8’ (1.5-2.5m) to prevent the stalks from becoming tough and hard to deal with. ¼ lb sows 250 sq ft. (¼ lb = 114 g, 250 sq ft = 23.2m2)

Sowing Sweet Corn
Young sweet corn with a sprinkler for overhead watering.
Photo Bridget Aleshire

I mentioned earlier here, that I’ve changed my mind about the necessity to put up ropes over corn seed rows to keep the crows off. I suppose there are fewer crows these days, sigh. Not needing the ropes makes the benefits of sowing with the seeder greater than the benefits of sowing by hand, so long as we can irrigate sufficiently to get the seed germinated. When we sowed by hand we watered the furrows generously, which meant we did not need to water again until after the seedlings emerged. If we hit a serious drought, the old method could still be best. Overhead watering does germinate lots of weeds, including in the wide spaces between the corn rows, so we need to factor in the extra hoeing or tilling when we weigh up the pros and cons. So, I’m a “situational convert” on this question!

How to Kill Striped Cucumber Beetles
Striped cucumber beetle in squash flower.
Photo Pam Dawling

I wrote about these beasties here. We handpick the beetles in the hoophouse squash flowers, hoping to deal with the early generation and reduce future numbers. One year we had our first outdoor squash bed very close to the hoophouse and the beetles moved there. In desperation I used Spinosad, an organically approved pesticide. It is a rather general pesticide, and harms bees, so I carefully sprayed late in the day and covered the row with netting to keep bees off. It worked brilliantly, taking a fraction of the time that daily handpicking takes. I became a convert to that method, but no one else on the crew did, so we went back to hand-picking.

Pruning Tomatoes
Hoophouse tomatoes in early May
Photo Bridget Aleshire

I used to maintain that life is too short to prune tomatoes, which grow at a rapid rate in our climate, and get fungal diseases, necessitating sowing succession crops. The past couple of years I have removed lower leaves touching the soil, and this year I reduced the sideshoots on our hoophouse tomatoes, which are grown as an early crop here.(We’re about to pull them up in early August, as the outdoor ones are now providing enough). I do think we got fewer fungal diseases, and the diseases started later compared to other years, so I am now convinced that removing the lower leaves is very worthwhile. We also got bigger fruit this year, which logically fits with reducing the foliage some amount.

Is There Such a Thing as Too Much Compost?
Too much compost?? A commercial compost windrow turner.
Photo by Pam Dawling

I used to think the more compost the better. Now I am more aware that compost adds to the phosphorus level in the soil. I wrote about that here. I am not as alarmist as some people about high P in our situation, but I do now think it is worth paying attention and not letting the levels build too fast. I have got more enthusiastic about growing cover crops at every opportunity, and finding legumes to include in cover crop mixtures at every time of year (see above about sunnhemp). I was already a cover crop enthusiast, but as my experience increased, I got my mind round more possibilities.

Using Plastics
Rolling biodegradable plastic mulch by hand
Photo Wren Vile

In my youth I was anti-plastic, If I were growing food just to feed myself, I’d probably still find ways to avoid almost all plastics, but growing on a commercial/professional scale (and getting older) has led me to appreciate plastics. I still don’t want to do plastic mulch, except the biodegradable kind, but I’ve come to accept durable light weight plastics for their benefits. Drip tape saves do much water, reduces weed growth. Plastic pots and flats are so much easier to lift! I do still pay attention and try to make plastics last a long time, and frequently salvage plastic containers others discard. I’m awed by the possibilities of silage tarps or old advertising banners, to keep down weeds without tilling and pre-germinate weed seeds so that when the covers are removed, few weeds grow. This was called by the awkward name of “occultation”, but is now more often referred to in English as tarping.

Hornworms

Lastly, I have a post on Mother Earth News Organic Gardening about hornworms, but you read it here first!