Purple Mountain Organics – Sustainable Market Farming

Insect mesh, shadecloth, crimson clover, sowing corn, too much rain

The May issue of Growing for Market is out, including my article about protecting crops in the summer, using shadecloth and insect mesh (netting).

If you want to grow lots of summer crops in buggy places, net houses (hoophouses covered with insect mesh rather than poly) may be your answer. If the bugs are not tiny, small mesh shade cloth may be an even better choice than insect mesh, because it cools while keeping the critters out. Search for project FS13-275 at http://www.southernsare.org. The document High Tunnel Pest Exclusion System: A novel strategy for organic crop production in the south is available from a link in that report.

Shade cloth on a bed of lettuce in summer. Photo Nina Gentle — Shade cloth on a bed of lettuce in summer.
Photo Nina Gentle

I write about using shade cloth for cool weather crops like lettuce during the summer, and also about research into the improvements to yields of peppers when using shadecloth. 30% shade cloth can increase pepper yields by 100% (yes, double the yield!). See the University of Georgia paper Shading helps south Georgia pepper farmers beat the heat. For hot weather lettuce, we use 45-60% shade cloth on spring hoops 6-8 feet apart, with a plastic clothespin to attach it at each hoop. Shadecloth lets air through better than row cover does, so it’s less likely to blow away. We don’t use any weight to hold the edges down. We keep the shade cloth on for 2-3 weeks after transplanting, then move it on to the next planting, in a single operation. 2 or 3 people pull up the hoops with the shade cloth still attached, and parade it like a Chinese dragon procession. We cover our hoophouse from mid-May to mid-September with shadecloth. Photo Kathryn Simmons

We cover our hoophouse from mid-May to mid-September with shadecloth.
Photo Kathryn Simmons

Rowcover (white polypro or polyester non-woven fabric) is often used by growers in cold weather to extend the season. There are also lightweight rowcovers for insect exclusion. These can be fragile, and holey row cover doesn’t keep insects out! We switched to only buying thick rowcover and use it for some crops even in summer. It doesn’t heat up as much as people fear. Johnnys Seeds has a helpful row cover comparison chart

ProtekNet over kale transplants in August. Photo by Bridget Aleshire — ProtekNet over kale transplants in August.
Photo by Bridget Aleshire

But even better for protecting plants against bugs in summer is ProtekNet, a translucent polyamide (nylon) fabric which comes in different mesh sizes. it allows better airflow than rowcover, and better light permeability (from the plants’ perspective) – visibility from the human perspective. Dubois offers free shipping on online orders over $200. ProtekNet is also available from Purple Mountain Organics in Maryland, and Johnnys Seeds in Maine.

Also in this issue of Growing for Market Jane Tanner writes about the benefits of no-till farming, in building topsoil, encouraging soil micro-organisms and reducing weed pressure. She writes about several farms, all following the model of small acreage, intensively farmed, mostly with manual tools. This system, advocated by Jean-Martin Fortier in The Market Gardener, includes “occultation”, the practice of covering damp soil with heavy black plastic for several weeks to kill weeds. This article includes photos of occultation and a clear explanation. Cover crops are another important feature of this system. I found this a particularly information-packed article, one I will return to.

9221576_orig Karin Tifft writes about IPM tools (Integrated Pest Management) for small and organic farms, making the topic accessible to those of us with only a short amount of reading time! We can read enough now to make some actual differences to our pest levels. Later we’ll want to read more, as results pile up.

Nikki Warner writes with advice for managing a farmers market, and Ralph Thurston and Jeriann Sabin write about starting a flower farm (Excerpted from their book Deadhead: The Bindweed Way to Grow Flowers with their permission.)

We sowed our first corn on Thursday. the soil temperature was 60F, so we were OK on that score. But then it rained and rained. The soil is saturated. I wonder if the corn seed will rot in the ground? Also the bean we sowed last week. Was I too hasty? We’ll see.

Meanwhile, a cheery sight has been the flowering crimson clover cover crop

Crimson clover cover crop Photo by Bridget Aleshire — Crimson clover cover crop
Photo by Bridget Aleshire

This patch is where our fall broccoli was last year. We under-sowed with a mix of crimson clover, Ladino white clover and medium red clover. If you look closely you can see the white patterned leaves of the red clover and the tiny leaves of the white clover in the understory. Also the seeding chickweed, which will disappear as soon as we bush hog the patch. Our goal here is to maintain the clovers all year, adding nitrogen to the soil for next year’s food crop and swamping the weeds. We’ll mow every time it looks weedy.

Winter rye and crimson clover cover crop Photo by McCune Porter — Winter rye and crimson clover cover crop
Photo by McCune Porter

In this second picture, you can see a patch where we sowed winter rye mixed with crimson clover in late October as a winter cover crop. In most places the rye is taller than the clover, so it’s not as overwhelmingly pretty as the first patch, but it’s packing a lot of biomass to feed the soil. It will get disked in soon (when the soil dries enough!), in preparation for later sweet corn sowings.

Three cheers for Ruby Streaks!

This week I’ve been marveling at Ruby Streaks, a beautiful ferny dark red leafy salad vegetable growing in our hoophouse. It brings a smile to winter salad mixes, a refreshing change from all the earnest shades of green. It’s beautiful, fast-growing, productive, easy to grow, cold tolerant, sweet-tasting,slightly pungent, and the seed is not expensive, what more need I say?

Ruby Streaks is so much more colorful and interesting than actual purple mizuna. For the botanists of Asian Greens among us, Ruby Streaks is a Brassica juncea, not B. rapa var japonica, like actual mizuna.

It can be grown and used as a microgreen (cut at small seedling stage), or a baby green after 21 days, and full size after 40 days. You could lightly braise it if you wanted it cooked. The leaves are finely serrated at the baby size and very similar to mizuna at full size. The stems are green and the leaf color ranges from dark green with red veins in warmer weather, to dark maroon in winter. Right now the color is incredible.

We harvest full size leaves by “crew-cutting” one side of each plant with scissors, then chopping them into short lengths. The plants regrow quickly.

It germinates quickly. Fedco warns that it bolts more readily than mizuna. We only grow it in the winter, when nothing is inclined to bolt, so this hasn’t been an issue for us. If you want to sow for spring, I’d recommend starting early in flats or pots indoors, and then transplanting at 4-5 weeks of age, about a month before the last frost date. Use rowcover for a few weeks.

To start in summer for a fall outdoor crops, you could again use flats, or you can make an outdoor nursery seed bed, protected with hoops and rowcover or ProtekNet insect netting from Fedco or from Purple Mountain Organics in Maryland. In hot weather it’s easier to keep outdoor beds damp compared to flats with a small amount of soil in them. We start ours 6/26 – the same dates we use for sowing fall broccoli and cabbage. The last sowing date is about 3 months before the first frost date. Transplant at 3-4 weeks of age, preferably not older. We haven’t tested out the cold-hardiness of Ruby Streaks, but I would expect it to survive at least down to 25F (-4C), the temperature mizuna is good to.

But the hoophouse in winter is where Ruby Streaks really shines! Double layers of inflated plastic provide enough protection in our climate for Ruby Streaks to grow all winter. And I do mean make actual growth, not just rest up waiting for spring! For winter salad mixes, we sow on 9/24 in an outdoor nursery bed, then plant into the hoophouse 10/24 (4 weeks old). We harvest that 11/1-1/25, by only cutting down one side of the plant at a time. After we clear that crop, we sow radishes in the space. We sow a second round of Ruby Streaks and mizuna inside the hoophouse 11/9, thin it into the salad, and then harvest from it 1/27-3/6.

Seed is available from Fedco, Johnny’s Seeds, Territorial, High Mowing, Kitazawa, and other seed suppliers. Fedco sells 1/2 oz Organically Grown seed for $5.20.

Ruby Streaks from Johnny's Seeds — Ruby Streaks from Johnny’s Seeds

There are relatives of Ruby Streaks, such as Scarlet Frills, Golden Frills, Red Splendor (Johnny’s) and Red Rain,and the beautiful Wild Garden Pungent Mix

Peak Watermelon Day?

This morning we picked 99 watermelons. I hope this is the peak day of harvest! We’ve been harvesting on Monday and Thursday each week since 7/30 or maybe 7/26, I’ve already forgotten! Numbers have leapt up: 10, 34, 37, 99. We need 22 melons a day during hot weather, to keep 100 people happy. So for all of August, September and a few days of October, we need 700-800.

But today’s 99 is not our all-time record. In 2010 we picked 120 on 7/31. And in 2008 we picked 320 on 8/20. That was too many and too late in the year. I’ve only got records back to 2000.

2000 was a bad watermelon year. We used to transplant into hay mulch, for weed control. Of course, we knew hay would cool the soil, and watermelons love heat. But we just couldn’t deal with the weeds any other way. We hadn’t started using drip tape irrigation back then, so our overhead sprinklers watered all the weed seeds in the aisles between the rows too. We used a vast space, with 10′ between the rows. We didn’t get ripe melons till well into August. 2001 wasn’t much better.

In 2002 I did some research into plant spacing and found we didn’t need to give the plants (and weeds) so much space. So we cut the row spacing down to 5.5′ and planted twice as many melons. 5.5′ is just the right width for unrolling big round hay bales between the rows. We started harvesting 8/3. Much better! We got 60/week in the middle of August and 100/week by the end of August. Still peaking much later than sensible. Watermelon in October is like yesterday’s newspapers – there’s not much demand.

2003 had a wet spring, we planted into mud. The harvest peaked 9/16. In 2004 transplanting dragged out. Our new rowcover had a manufacturing defect and disintegrated like wet toilet paper all over the field. We got our money back but the plants were set back by the lack of cover when they needed it. We started saving our own seed that summer, selecting for early ripening and good flavor. Also presumably for spring cold-hardiness as they were from plants that didn’t die.

In 2005 I did more research into spacing, and we planted 2.5′ apart in our 5.5′ rows. It seemed wiser to plant closer and go for more plants and so more first melons (one on each plant), as it is early ones that we want. Keeping geriatric vines alive to produce a third melon or so seemed to be missing the whole point of eating watermelon in hot weather.

At this point in our history, we were still harvesting up until frost (average mid-October here). We were planting about 1260′. We started to track how many melons we had on hand and what rate we were consuming them, so we could decide when we had enough and stop picking.

In 2008 we had no hay mulch available. From this disaster came a wonderful thing: we discovered biodegradable plastic mulch. We have used two brands: Eco-One Oxo-Biodegradable mulch (made in Canada) and Bio-telo (made in Italy). This product is made from non-GMO corn and it starts to disintegrate after a couple of months in the field. It’s very thin and easily torn if the soil underneath is not smooth. It’s perfect for vining crops, because it stops the weeds growing and doesn’t disintegrate much until after the vines cover the whole area. And the big plus is that the bio-mulch warms the soil, rather than cooling it. Biodegradable mulches are now available in smaller pieces for backyard growers, from Johnnys Selected Seeds and Purple Mountain Organics.

We planted 1800′, more than usual because the area the rotation brought them to was a bowl shaped garden where crops sometimes drown in wet years. We started harvesting 7/31, and numbers rose rapidly.We didn’t get any floods. By 8/20 we had harvested 1000. That was the year we decided not to wait for frost, but to disk the patch in early and get a good cover crops established for the winter.

2009 had a peak harvest of 174 on 8/15. I think we stopped at 835 total on 9/2. 2010 records show an early start with 2 harvested on 7/18. We stopped at 665 on 9/8. We tried to experiment with various row spacings and plant spacings, but once the vines all meshed together and the weather got hot, our enthusiasm for science waned! We were planting 1060′. August had an inhuman workload, and we decided to see what we could do to reduce August tasks for future years.

In 2011 we decided to plant less, as were short of workers. We planned on 1080′ but then cut back further, and only planted 900′. This year we only planted 800′, with plants 36″ apart, so a lot fewer plants than in the old days of 1800′ and 30″ spacing. The melons are huge this year – I bet we don’t eat 22 of these a day!

So, having looked at the numbers here in the relatively cool office, I deduce that we haven’t picked anything like enough yet, and need 5 more 99-harvest days before we think about quitting. Time to start using the truck rather than the garden carts, for hauling them away. We’ve found the hard way that even though we can get 20 or so melons in a garden cart, it damages the carts and wrecks the tires. So now we keep to a 16-watermelon limit and save the carts.

Sowing greens for fall

Senposai 2 — Senposai – a delicious, cold-tolerant leaf green

One of my tasks this week has been sowing fall greens. I start sowing in the third or fourth week of June, and set aside time once a week for about six weeks, to sow more and weed and thin the older seedlings. The first two weeks are the most intense, and if I’m successful with those, I have a lot less work in the weeks following. If something goes wrong, I resow whatever didn’t come up, or died.

For fall greens, we don’t sow in flats but directly in a nursery bed, covered with rowcover on hoops to keep the harlequin bugs and flea beetles off. It’s less work, easier to keep them all watered, and they are not cramped in small cells: they make good roots and are more tolerant of hot conditions.

This year we are growing twelve different varieties of broccoli and eleven of cabbage! We hope to compare them and next year just grow the best few varieties of each crop. We are growing to feed the hundred members of Twin Oaks Community, not to sell to a wholesaler, so we want a long broccoli season, and sideshoots are as important to us as main heads. We want cabbage that stores, as well as cabbage that is ready quickly. Our broccoli patch is part of the Novic trials, so we hope others will learn from our plants too.

To organize all these different sowings I have a spreadsheet and a map of the nursery beds. I prepare the bed, make the furrows, write a plastic label for each variety, measure the rows, set the labels in place, then water the furrows very thoroughly before sowing the seeds and covering them with (dry)soil from the sides of the furrows. This is a good way to help seeds germinate during hot dry weather: the seeds sit in the mud, where they have enough water to germinate and get up above ground. It’s much more successful than watering after sowing, when you sprinkle water on a dry surface and hope in goes down deep enough and doesn’t evaporate. And, contrary to some myths, brassica seeds can germinate very well at high temperatures. They just need the water right there where the seeds are.

We’ll transplant our seedlings when they are 3-4 weeks old, watering first, then

Kohlrabi young plant — Kohlrabi is another of the less-common brassicas. We like to mix the purple plants with the green ones

digging them up and setting the bare-root transplants out in their rows. We’re planning 2000 ft of broccoli, 1300 ft of cabbage, 540 ft of senposai (a delicious tender leaf green with some frost tolerance), 360 ft of kohlrabi, and 90 ft each of Chinese cabbage and Yukina Savoy (a cold-tolerant giant tatsoi). That’s plenty of plants to rehouse in a short time and keep alive and happy.

This year we are trying two new things. One is Proteknet in place of rowcover. It’s a fine mesh nylon fabric that keeps bugs out, but lets more light in than most spun-bonded rowcovers, and has much better airflow. We think we’ll have healthier plants. Also, we can see them through the mesh, so we know they’ve germinated and can spot problems early. One year we checked under our rowcover and found fleabeetles had got in and had a busy week, chomping along the rows. We got the ProtekNet from Purple Mountain Organics in Maryland, suppliers of good tools with the personal recommendations from the company.

The second new thing we’re trying is drip irrigation in the field. We use drip for some of our crops, but previously we used overhead sprinklers for the fall greens. We’ve had trouble in recent years with the extremely hot weather in late July and early August when we transplant. We think setting out the drip irrigation and running the water while we plant will help the plants get over their transplant shock. And we’ll be able to give them an hour of water in the middle of each day for the first week, to help them face this brutal weather we’re having. And the best bit is: they can get their mid-day watering without me walking up and down dragging a hose. I can be indoors blogging!