Root Crops in September

 

Root Crops in September

Cherry Belle radishes in the fall.
Photo Pam Dawling

Root Crops to Plant in Central Virginia in September

In September the days get shorter and we get our last chance to plant crops to feed us during the winter. Much more of our garden time will be spent harvesting this month!

In early September we can direct sow several root crops.

  • Daikon and other winter radish (in very early September);
  • Turnips (by 9/15);
  • Kohlrabi only takes 60 days from sowing to harvest. They can be direct sown or transplanted from flats or an outdoor nursery seedbed at the beginning of September. Kohlrabi is hardy to about 15°F (-9.4°C). Our night temperatures will be higher than that until the beginning of November;
  • Small radishes by mid-September. We usually squeeze these in on the south shoulder of a bed of kale, because they grow quickly and we don’t need a whole bedful. By the time the kale needs the space, the radishes will be gone.
  • In the hoophouse, we start our winter crops by sowing radishes and leafy greens on 9/6 or 9/7.
A bed of young growing turnips.
Photo Pam Dawling

See Root Crops in August for more details on these.

It’s too late for any slow-growing crops like carrots. We can just squeeze in some beets at the beginning of September, if we take good care of them. Hoeing, weeding and thinning at the first opportunity will help them grow a bit faster and make up for lost time. We could cover them with rowcover to warm their airspace and soil, once we have got them established and tidied up. I hate to cover weedy crops with rowcover – you just know it encourages weeds to grow faster! Beets won’t die of cold until 12F for my favorite, Cylindra, so they have quite a while yet. See Root Crops in August for more about fall beets.

Radish succession crops

In our winter hoophouse, we sow radishes six or seven times. It is a science and an art to time the sowings to provide a succession of delectable little radishes with no gaps in supply and no overlap of plantings and gnarly big roots. I have made a graph of radish sowing and harvesting dates to help us even out our supply.

Here’s a chart. 1/25 is our last worthwhile sowing date for hoophouse radishes.

Radish #1 sown 9/6 Harvest 10/5 – 11/15
            #2 sown 10/1 Harvest 11/6 – 12/25
            #3 sown 10/30 Harvest 12/16 – 2/7
            #4 sown 11/29 Harvest 1/16 – 2/25
            #5 sown 12/23 Harvest 2/19 – 3/16
White Icicle radishes in our hoophouse in winter. Photo Pam Dawling

Root Crops to Harvest in Central Virginia in September

During September, the root crops we can harvest include beets (and beet greens), carrots, radishes, turnips and horseradish (which I have more to say about below). We hold off on parsnips, if we have grown those, as the flavor improves a lot after a frost.

We could harvest potatoes, which I have written about in Potato Harvesting and Root Crops in June. We hold off on sweet potatoes until October, and I’ll write about them in a post of their own in a few weeks. If you need to harvest earlier, read the chapter in Sustainable Market Farming.

Special Root Crop Topic for September in Central Virginia: Horseradish

Horseradish plant.
Photo Harvest to Table

Horseradish, Armoracia rusticana, a perennial, is very easily propagated from pieces of root. It can be hard to get rid of if you change your mind! It’s wise to plant your perennial food crops in a special place that isn’t part of your annual crop rotation space. Remove all perennial weeds before planting horseradish or any other perennial vegetable. Ours is beside our grape vines, near our rhubarb. Full sun or partial shade will work. Horseradish looks like a big bad dock growing, but is in fact a brassica. Horseradish can provide value-added products for out-of-season sales, as well as a pungent treat in cold weather.

Horseradish root.
Photo GrowVeg

Buy or beg crowns or root pieces, and plant them 4-6 weeks before your average last frost date. Horseradish grows best in cool, damp regions with temperatures between 45°F (7°C) and 75°F (24°C). But in central Virginia, temperatures go from 0°F (-18°C) and 100°F (38°C) and we have more than enough horseradish, so don’t worry too much about that temperature range.

Plant crowns just at soil level. Plant root pieces with the top just below the surface and the bottom end covered with 2-3’ (5-8 cm) of soil. Space horseradish plants 24-36” (60-90 cm) apart. If you are worried about it spreading into important nearby plants, create a metal, wood or stone barrier 24” (60 cm) deep around the bed.

Keep the soil damp, add some compost once a year. You are unlikely to have any pest or disease problems with this crop. Young plants should not be harvested until the leaves are at least 12” (30 cm) long.

Horseradish plant.
Photo Nourse Farms

Horseradish is traditionally harvested September-April (the months with R in them!). The roots go as much as 2 ft (60 cm) deep and are very strong (but not as sturdy as gobo, Chinese burdock). Use a strong shovel, spade or digging fork, and start loosening the roots from 6” (15 cm) away. If you hear or feel a root snap, be glad! The goal is to extract some of the roots and firm up whatever remains, to continue growing. Water the plants after harvest if the weather is dry.

Collect the harvested root parts in a bucket, and wash them right away. You can store them dirty, but it is harder to get them clean later. Harvested roots can be refrigerated for several months until used – they seem fairly impervious to rot.

When you process horseradish do it outdoors, with googles on. I kid you not! This can be a good porch activity in sunny chilly weather. After thoroughly washing and scrubbing the roots, peel them carefully. Throw the peelings in the trash, not the compost pile, as they easily regrow from tiny pieces!

The peeled roots can be ground up in a food processor, to make relish or sauce. Or if you prefer, use a fine grater.

Harvested horseradish roots.
Photo Wikipedia Kren_Verkauf

If you want to buy plants, try Nourse Farms

If you’d like to read more about horseradish, including container plants grown as an annual, there’s info on Harvest to Table

If you’d like to read how to make the condiment, see Barbara Pleasant’s article on GrowVeg

Other Root Crop Tasks in Central Virginia in September: Washing, sorting and storing root crops

Harvesting

How you harvest roots depends on the scale of your farm and the equipment you have. For example, with carrots, you can mow or tear off the tops, then undercut with machinery, then lift. Or you can use the tops to help get the carrots out of ground, as we do, loosening them with a digging fork, then trim.

Ensure gentle treatment and no bruising of roots while harvesting. As we all know, it is important to avoid bacterial contamination. Wounds and abrasions can lead the crop to pick up new bacteria from the environment. Crops can be punctured by sharp edges of containers as well as the more obvious knives and fingernails.

The wash-pack house at Finca Marta, Artemisa, Cuba
Photo Pam Dawling

Trimming

Our method is to bring the harvested roots to a shady spot to trim, wash, sort and bag. We have a printed sheet, optimistically called “Perfect Vegetable Storage” to help us remember from year to year the tips we have learned. Usually we need scissors or knives for a clean cut, and usually we aim to leave about ¼” (0.5 cm) of leaf-stems attached to roots. It might be quicker to tear the leaves off, but this doesn’t give such good results and can cause the crop to need extra storage space. When we harvest carrots for immediate use, we snap the tops off right at the junction of the foliage and the root. When we harvest for storage, we trim with scissors to leave a small length of greens.

Washing and rinsing

After washing, and perhaps before, comes cooling. Make full use of all possibilities, such as damp burlap, or high percentage shade cloth, or the shade of trees, buildings, or a truck. At the washing station, crops may be sprayed down on a mesh table, or dunked in troughs or buckets of clean water. Washing can also act to cool the crop.

Draining away the water is important. Drain on a mesh table or in a holey bucket, a suspended mesh bag or laundry basket. Barrel root washers have the draining stage built in. We don’t have a rotary barrel root washer, much as we’d like one. Here’s our manual method.

  1. As you cut, gently drop the roots into buckets of water. This lets the dirt wash itself off to some extent, as you continue to cut more. Use whatever size and type of container seems most efficient.
  2. When the wash container is full, switch from trimming to washing: rub each root with your hands and drop it gently into a container of clean rinse water. Depending on the cleanliness of the roots after washing, it may be possible to reuse the rinse water. Or else make it be wash water for the next round. Once the water is quite dirty it needs to go. Gently pour it round a tree, or on the ground somewhere else. Avoid causing a washout by flinging a bucketful all in one place. Rinsing needs pretty clean water.
  3. When the rinse container is full, get two clean holey buckets. Take the roots one at a time out of the rinse water (don’t rub then any more, just lift them out). Sort as you go.
Harvested Purple Top Milan and White Egg turnips.
Photo Pam Dawling

Sorting storable roots from non-storable

  1. Decide if the root is Storable or is Use First (cull, or home use). Storable are sound, reasonably large. Use First may be small (less than ¾” diameter, less than 3” long, maybe) or damaged (deep holes, soft spots, fresh complex cracks). Open dry cracks or snapped-in-half roots may heal over and store just fine.
    Bucket lid with holes for sorting root vegetables for storage.
    Photo Wren Vile

    We made different sized holes in a special bucket lid, to help new people get an idea of size.

  2. Put the storable ones in one holey bucket and the non-storable (Use First) in the other. It helps to have 2 different colored buckets. It’s better to err on the side of calling doubtful ones Use First, but it’s even better to learn good sorting, as too many Use First roots can’t all be used quickly.
  3. When a Use First bucket is full, set it aside, or put on the cart or truck. Once a Storable bucket is full, set it aside to drain thoroughly before bagging. Do not confuse categories. Do more trimming, washing, rinsing, sorting.
  4. When the Storable roots have drained, get a well-perforated plastic sack. Ensure there are enough holes and big enough ones. Buy perforated bags or perforate your own. If you need more holes, the safest method is to lay the bag on the grass, stand on diagonally opposite corners, then stab the bag with a largish knife. Make about 3 cuts across the width of the bag and about 6? 7? 8? down the length. Or fold the bag and use a 3-ring paper hole punch in several places. Refold and repeat.
  5. Gently pour the Storable roots into the well-perforated bag. We usually use 50 pound bags. Tie the neck with a short length of rope and make a masking tape “flag” label with the date and the type of vegetable.
Sweet Potatoes in storage.
Photo Pam Dawling

Storing

When all the bags of storers have been gathered up, record the number going to the cooler on an Inventory clipboard. If there is no official tally sheet, make one on a full size sheet of paper.

We store bulk roots in a walk-in cooler, up on a high loft/shelf. Use pallets in the loft for better airflow under the bags. Start a new pallet for each different type of vegetable and for a substantially different date, eg fall carrots separate from spring carrots. Keep inventory: once a month, someone takes stock of what we have and updates the list.

See Root Crops in August for details on sorting newly stored potatoes

Back-up plans for winter hoophouse crops

Lettuce “filler” transplants to fill gaps.
Photo Pam Dawling

Because crops grow slowly in cold weather, if something goes wrong at the beginning of the winter, or in the fall, the consequences can cast a long shadow. It is not easy to make up for lost time. In spring, the weather is getting warmer, the daylight is lengthening, and you may have noticed that later sowings can catch up with ones a week or two earlier, allowing for a second chance. In the fall, the rate of growth is moving in the opposite direction, and later sowings will stand no chance of catching up. Even worse, they may get “trapped” like Persephone in the Underworld during the dark Persephone Days. But don’t despair – there are things you can do ahead of time to be prepared for plans going awry, and there are even a few things you can do instead of your original plan, to ensure you get some crops to harvest.

Transplant seedlings under insect netting outdoors.
Photo Pam Dawling

Starting outdoors in September

We sow a lot of our winter crops outdoors in September, and transplant them into the hoophouse in October. This gives us an extra few weeks to prepare the hoophouse beds, and gives the seeds the cooler outdoor conditions to germinate in. We have three sowing dates.

On September 15, we sow 10 varieties of hardy leaf lettuce and romaines; pak choy, Chinese cabbage, Yukina Savoy, Tokyo Bekana, Maruba Santoh and chard

On September 24, we sow another 10 varieties of lettuce; Red and White Russian kales, Senposai, more Yukina Savoy, mizuna and arugula, and we resow anything that didn’t do well in the 9/15 sowing

On September 30, we resow anything that didn’t do well in the 9/24 sowing, or substitutes.

Emergency back-up seedlings for the hoophouse.
Photo Pam Dawling

This year, we had poor germination of a lot of the 9/15 sowings and too many of the 9/24 sowings. As a back-up for the back-up plans we sowed some crops in Winstrip trays, and spotted lettuce in open flats, which we kept inside the hoophouse. By that point, conditions in the hoophouse were more crop-friendly than outdoors. We did need some of these, and the rest we harvested for salad mixes right out of the flats! We were short of salad items because of the late establishment of the plants, so every plant was a help!

A flat of lettuce transplants in the path in the hoophouse.
Photo Pam Dawling

Our goal is to keep the space filled with useful crops.

Success with this goal relies on a cluster of strategies

  1. The fall transplant program I describe above.
  2. Follow-on crops: A sequence of different crops occupying the same space over time. It’s important to know when crops will bolt, and how to plant sensible quantities
  3. Filler crops: As well as scheduled plantings, in October we sow a few short rows of spinach, lettuce, Senposai, Yukina Savoy, Maruba Santoh, Tokyo Bekana to transplant into gaps as soon as they occur. We simply dig them up, replant where needed and water well. Bare-root transplants are much easier than many fear. They save time and money, compared to growing starts in flats, and save on greenhouse space. They are very sturdy plants, as they have the full depth of soil to develop big roots. Little extra care is needed, as they are less prone to drying out than seedlings in flats. Alternatively you could keep some plug flats of these plants handy. We fill gaps with Asian greens, spinach or lettuces as appropriate, until Jan 25. From Jan 25 to Feb 20 we fill all gaps everywhere with spinach From Feb 20, we only fill gaps on the outer thirds of the beds, leaving centers free for tomatoes, etc.

    Filler brassica transplants in our hoophouse in November.
    Photo Pam Dawling
  4. Interplanting: After 2/20, we harvest the winter crops from the center rows first, plant the new early summer crops down the center, then harvest the outer rows bit by bit as the new crop needs the space or the light. This overlap allows the new crops to take over gradually. Our winter and spring crops end in April
  5. Fast Catch Crops. Some cool-weather crops mature in 60 days or less. Mostly these are greens and fast-growing root crops. Useful if a crop fails, or you have a small empty space. Details on some of these follow the list.
  • Ready in 30–35 days in fall, longer in winter: arugula, many Asian greens (Chinese Napa cabbage, Komatsuna, Maruba Santoh, mizuna, pak choy,.Senposai, tatsoi, Tokyo Bekana and Yukina Savoy), brassica salad mixes, chard, kale, radishes, salad greens (lettuce, endives, chicories) spinach and winter purslane. Peashoots in late winter or spring.
  • Ready in 35–45 days in fall: chervil, corn salad, land cress, parsley and sorrel.
  • Ready in 60 days in fall: beets, small fast cabbage, collards, kohlrabi and turnips.

 Asian Greens

Asian greens are better able to germinate in hot weather than lettuce, and are faster growing than lettuce. Transplant 2-3 weeks after fall sowing, or direct sow.

Asian greens are nutritious as well as tasty – flavors vary from mild to peppery – read the catalog descriptions before growing lots. Colors cover the spectrum: chartreuse, bright green, dark green and purple. A diversity of crops without a diversity of growing methods!

Brassica (Mustard) Salad Mixes

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 10/2 and 11/14 for winter harvest and from 12/4 to 2/12 for March and early April harvests. We’re zone 7, central Virginia.

Chard and Beet Greens

Green chard is hardier than the multi-colored Bright Lights. Days to maturity: 61 – 103 days, a big difference, depending when you sow. Sow 9/15, harvest 11/15 – 5/10; Sow 10/26, harvest 2/6 – 5/10.

Radishes in our hoophouse in February.
Photo Pam Dawling

Radishes

Varieties we like: Easter Egg, White Icicle, and Cherry Belle.  Sparkler got too fibrous for us, as did Cherry Belle after mid Oct. We make 6 sowings 9/6 – 1/26. Small radishes take 27–52 days to maturity, not counting days too cold to grow.

Scallions in our hoophouse in late November.
Photo Pam Dawling

Scallions

We sow 9/6 for harvest 12/1 – 3/1; 11/18 (following radishes) for harvest in early spring. This winter we are trying a sowing 10/20 also (we happened to have a space at that time, in a spot where it fitted our rotation). Evergreen Hardy White and White Lisbon scallions are hardy down to 0°F (-18°C)

Spinach

We loved Tyee and now grow Escalade, Reflect, Acadia and smooth leaf Renegade. Renegade makes good Nov/Dec growth; Acadia, Escalade yield well Jan – April; January sown Reflect does well.

  1. Succession Planting for Winter Hoophouse Crops

We do 2 sowings of chard, scallions, tatsoi and yukina savoy; 3 sowings of  mizuna, turnips and bulb onions; 4 sowings of baby lettuce mix and brassica salad mix; 5 sowings of spinach and radish. Our goal is to provide a continuous supply.

As temperatures and day-length decrease in the fall, the time to maturity lengthens – a day late in sowing can lead to a week’s delay in harvesting. As temperatures and day-length increase after the Winter Solstice, the time to maturity shortens – later sowings can almost catch up with earlier ones. To get harvests starting an equal number of days apart, vary the interval between one sowing date and the next accordingly. Here’s the most dependable method:

Making a Close-Fit Plan Using Graphs

  1. Gather sowing and harvest start and finish dates for each planting of each crop you are growing as successions.
  2. Make a graph for each crop: sowing date along the horizontal (x) axis; harvest start date along the vertical (y) axis. Mark in all your data. Join with a line. Smooth the line.
  3. From your first possible sowing date find the first harvest start date.
  4. Decide the last worthwhile harvest start date, mark that.
  5. Divide the harvest period into a whole number of equal segments, according to how often you want a new patch.
  6. Mark in the harvest start dates and see the sowing dates that match those harvest dates
Overgrown hoophouse filler greens in our hoophouse in December.
Photo Wren Vile

Working around the Persephone Days

In Indiana (in Zone 5b) Ben Hartman (The Lean Farm) sows salad greens & spinach for winter harvests every week Sept 15–Oct 15. Baby lettuce sown before Oct 22 takes 5–6 weeks until harvest. If sown Oct 24–Nov 16, it takes 8–17 weeks to harvest. In Zone 5b, if you want baby lettuce mix before December, sow before Oct 22.

Spinach sown before Oct 11 takes 4–6 weeks to harvest. If sown from Oct 20–Nov 1, it takes 12–15 weeks. To harvest spinach before December, he sows before the middle of October.

For new year harvests he sows every week Oct 15–Nov 1. He then takes a two month break from planting (Nov-Dec). Jan 1–Jan 15 he sows both salad greens and spinach for late winter.

In Zone 7 we can harvest outdoor lettuce and spinach in December, and we have less urgency about early hoophouse sowings (and we get no winter break!).