In the August issue of GFM I covered the beginnings of winter cropping. Now I’ll finish with this large part of our farm’s operations by covering soil management, planting, and harvesting; saving cold-hardy seed; greenhouse management; human comfort and safety; and sales.

Soil management and planting
Proper soil management for successful winter cropping revolves around two core goals: drainage and tilth. Winter and spring across much of the U.S. are the times of year when soils have the greatest chance of being saturated with water. Sodden soils over long periods threaten plant roots with anaerobic conditions, a sure way to stunt the great majority of crops. And harvesting in poorly draining soils can become a discouraging waltz with mud.

Tilth is, very crudely, the degree of fluffiness, cloddiness, or aggregation that lets a soil drain and breathe. Good tilth and good drainage permit plants roots to properly thrive, respire, and search for nutrients. Both also promote faster departure of all that water from a winter system once the ground has thawed.

A sure way to make winter harvesting a misery and to increase the chances for full-blown crop failure is to ignore drainage and tilth while preparing your ground for planting. We, our tractors, and our misconceived notions of how smooth a seed bed should be are, in my view, prime enemies of good tilth and good drainage. Overwork your soils and you will greatly decrease your odds for a successful winter crop. For winter, we use an extensive approach out in the fields: minimal investment of tractor and human time per acre, and lots of acres planted with diverse crops in order to have plenty of plants to choose from after particularly hard freezes. Over 18 to 20 acres, we prep the 4’- 6’ wide crop beds by mowing the summer fallow, plowing, and lightly disking once or at most twice. We direct sow using a push seeder when the clods are small enough, or by broadcasting between the above two light diskings if the field is still really rough after our permitted tillage and if the cultivar isn’t picky about spacing. The 8’ wide traffic beds between the cash crop beds are not plowed, only disked, broadcast generously with an appropriate cover crop, and lightly disked once more. I decide on particular cover crops based on that soil’s needs (e.g., a blend to produce lots of biomass for our sandier soils) and on the specific warm-season crop that will follow seven or eight months hence in our planned rotation. If we weren’t certified organic and so barred from using herbicides, I’d till even less.

What does this acreage-extensive, rough-till approach do for us? It gives us aerobic soils in which plant roots can easily do their jobs. It gives us traffic beds that don’t puddle, that let the whole system drain superbly, and that are pleasing to harvest from when the fields are wettest. And the approach repairs and builds the soil tilth that can suffer under more intensive summer cropping. Driving this system are the soils and the plant roots, not the tractor nor any dangerous goal of smooth planting beds. I can’t sell beautifully weed-free, over-tilled soils; I can’t market lovely fine seed beds or their flip side, muddy anaerobic fields when we get too much rain. What I do sell are outstanding crops in more months and far more reliably than do any of my competitors.

The prices we pay are small indeed: uneven, cloddy walking through rough fields, and, in the traffic beds, mowed but unsightly summer weeds that persist until the freezes and the clovers finish them off. And we develop really strong ankles.

A different soil management system with high potential for cold-season success combines raised beds, intensive tillage, and lots of animal manures. The manures not only generously supply nutrients for crops but also build outstanding tilth in what would otherwise be an over-worked soil system. This was described by Henderson for very successful winter cropping more than a century ago. The most eloquent and insightful modern farmer that I know that uses the intensive system (not necessarily for winter cropping) is Polly Armour of Four Winds Farm in Gardiner, NY. Our farm would use this second approach for high-value crops if we had more ruminants and if our soils were lower in phosphorus. Nutrient excesses remain a threat in manure-based systems.

We no longer plant any outside winter food crops by transplant. All are direct sown. This is because the added work of transplanting seems to have a negative effect on over-wintering in experimental same-year, side-by-side plantings. In lettuces, cabbages, spinach, broccoli, and Brussels sprouts, the first deep soil freeze usually kills 30% to 80% of transplants. And winter has only just begun. I suspect that this higher mortality stems from a transplant’s frequent loss of the tap root, with its apical dominance and drive to go deep. Many transplants instead re-initiate root growth with laterals that are more superficial – a dangerous approach when the upper soil freezes early and often.

Harvesting
We harvest outside winter crops in four main ways. Smaller leaves for mesclun are cut-and-come-again on a weather-dependent 10-day to 35-day cycle. Whole-plant harvesting is reserved for baby lettuces, tat soi, and root crops. The vast majority of cooking greens are harvested selectively, leaf by leaf, choosing the best-looking leaves but never cutting more than 40% of each plant. The final technique is rogueing, the intentional destruction of runts and off-types, with sale of their leaves. This makes the crop pay for its own genetic improvement. Beds that will eventually be harvested for seed are always subjected both to rogueing and to between four and twelve cycles of either cut-and-come-again or selective leaf harvesting. Routine whole-plant harvesting would in contrast tend to remove the best individuals from a breeding population – a real mistake if you want superior parents for next year’s seed.

Saving seed
Seed saving and genetic management are keystones of our winter cropping system. Yes, we start with seed purchased from good companies. But then we harvest the seed, during April, May, and June, of the best plants among the larger group of survivors. I covered this in detail in GFM August 2002 through October 2002 (Editor’s note: The articles are now available in the 106-page compilation of 2002 issues; the cost is $20. Ordering information is on page 2.) and urge you to consider the arugula example as one template for improving seed for winter profits. I will here much more briefly outline the ideas and central details of genetic management of winter crops.

The core concept is that winter is tough, and after sowing unimproved seed you are going to see some and maybe a whole lot of plant death caused by freezes, ice, and wind. But if all conditions in your field were equal across that stretch of frozen ground, then any plants that survived would likely have some genetic advantage. You want to let these survivors breed, and save that seed. By doing so you are increasing the frequency of genes for winter survival in your new batch of seed. If the next winter is equally or less severe, the newly improved crop will have a higher level of survival. And of profit: genes for freeze tolerance enable harvests and harvests mean money. The results of such a simple process can be fast and dramatic: purple Asian mustard that came to our farm with 80% winter mortality now loses 0-5% in normal winters and about 10% in the most severe seasons. After 3 to 12 years of selection, our main kales, arugula, collards, and three other Asian mustards have 100% survival regardless of winter severity.

You can attain the same. The steps are:
1. Choose a cultivar likely to have some cold tolerance already built in, eg. curly kale, old-fashioned cilantro, or Rouge d’ Hiver lettuce, and choose a seed provider likely to sell you the best in winter-hardiness.
2. Isolate beds or fields for eventual seed harvesting by as great a distance as you can from potential cross-pollinators. We assume that the cresses form one pollination group (i.e., they cross-pollinate each other but won’t cross with other groups); arugula is not at all a contaminator; kales, collards, Brussels sprouts, cauliflower, and broccoli form a third group; typical mustards a fourth; and turnips can contaminate the third group readily.
3. Direct-sow a minimum of 1 oz. and preferably 8-16 oz. of this seed between late August and early October, depending on your zone.
4. Treat normally with irrigation, soil fertility, weed control, etc.: do not baby this crop. Do NOT destructively harvest any of this first crop before spring. Instead, harvest all plants using cut-and-come-again or selective leaf cutting (see Harvesting section), leaving the crown intact.
5. Once real spring occurs, assess survival. You’ll want a minimum of 30 to 50 superior plants to be the progenitors of your new improved line. Thousands of superior “mother plants” is better and is our farm’s path. Rogue (destructively harvest) the runts, the off-types, and any diseased individuals before flowering begins.
6. Once seed-setting begins, stop harvesting any leaves. Let them ripen their seed unharassed.
7. Save, process, and store this seed correctly (see reprints; not covered here).

What you can end up with is really fine seed adapted to the harshness of winter as well as to your local environment. These are agricultural assets far superior to seed-company materials grown where deep freezes and frequent leaf harvesting don’t hit most seed crops.

Greenhouse management
We manage our winter greenhouses by sticking to three simplifying principles: keep N low, use chickens to destroy large insects and slugs before any planting begins, and keep heating affordable.

We no longer overly fertilize our greenhouse lettuces. We used to want beds loaded with nitrogen to maximize yields, but aphids became a nightmare. Keeping N low means that we haven’t sprayed the greenhouse greens in over three years. The crops do get some residual fertilizer that presumably leached the preceding spring, from all the flats of warm-season transplants that we start. Briefly running chickens in the greenhouses also adds fertilizer, but we usually only give the birds 5-14 days of August access before the September lettuce sowing. We pay a high price if we skip this step: slugs and especially grasshoppers and crickets can whack many an emerging lettuce crop. And organic heirloom lettuce seed isn’t cheap. Keep in mind that chickens can bake in an unventilated August greenhouse: give the birds free access to the outside, and they’ll clear the greenhouse of many pests in the cooler morning hours.

Our final principle for profitable all-winter greenhouse use is to keep heating affordable. Our period for really intensive greenhouse heating is January to March, when we are starting the majority of our warm-season transplants. While we have huge propane heaters in our oldest greenhouse, wood has fully supplanted purchased fuels. We had our welder use a secondhand 280-gallon oil tank to make the body for an airtight, large-volume wood stove. A large industrial fan circulates the warmth. This is not nearly as efficient as more expensive wood-fueled systems that circulate hot water, but it cost less than $600. We have 50 acres of woods and our farm is beset by hurricanes and windstorms often enough that cleanup and firewood go hand in glove. Further, this thrift extends even to vital crop fertilizer needs: all potassium used by our crops over eight years has come from broadcast wood ash plus low initial residual K. Many tons of tomatoes leave our farm every summer to feed urban customers, but our soils test adequate for K if I keep the house and greenhouses warm. I avidly read and re-read the GFM article by Carl Benson (January 2004) on heating with converted old cooking oil. That is creative thinking and skillful resource management, and I urge any readers who want to run greenhouses all winter to consider all such alternatives to fossil fuels. Propane costs $110 per frigid night to keep one greenhouse as warm as does the wood stove, and January’s frigid nights can be followed by February ice storms.

Human comfort and safety
Winter cropping is glorious, invigorating, and rewarding. But dressing appropriately is the only way to look forward to each day. Above 38° F regular clothing will do. From 34° to 38° F, or in cold driving rains, we are addicted to Carhartt coveralls (the quilted full body suit). Knock-offs usually lack Carhartt’s long-lasting insulation and triple-stitching. Below 34°, we layer underneath the Carhartt’s, as well as wear stocking caps. Having no seam for the icy winds to plague one’s backside makes a huge difference. In Carhartt’s, I am impervious. I urge you to spend the money for such superior protection. We are all more efficient harvesters when we are toasty.

Gloves are crucial. We use both nitrile and leather. Nitrile gloves are tight-fitting surgical-type gloves much superior to latex. These act as do wetsuits for scuba diving. Nitrile gloves cost more (about $6.50/hundred) but last a lot longer than latex and are available at plumbing supply houses. Between 38° and 45° F, we use one per hand, maybe with a leather glove as well (fingertips cut off for dexterity). Below 38° F, we use two nitriles per hand. Below 30° F or in freezing rains, leather usually goes over the nitrile pair. Nitrile plus leather with fleece works nicely to about 22° F, but at that temperature you shouldn’t be harvesting greens. All this may sound obsessively preoccupied with layering, but the sheer grind of meeting January and February crop delivery deadlines needs to be softened by hand and body comfort.

Finally, greenhouses are not just for crops. They can warm you quickly when you are on the edge of freezing. I burn that wood furnace in part just to have a hot surface for iced fingers. Greenhouses let you thaw and be productive.

Marketing
The most cherished part of winter cropping for me is the walk back to the house from the greenhouses and barns. The sun has fully set, the velvet night sky is bejeweled with the constellations, and behind me, loaded for tomorrow’s delivery, are many many cases of about the best frost-bit greens grown anywhere.

The second-most cherished part of cold-season cropping is the market. We are utterly alone in the field: in our region, I know of no other farmers who, even in the gnarled heart of winter, do this on our scale. A thousand acres of winter greens could enter the production stream from every state in USDA zones 6, 7, and maybe 8 and the market would barely be dented. This contrasts most strongly with summer cropping, where glut is the dispiriting rule and we all race for diminishing returns in what is, by August, a buyers’ market. Summer is not very kind. But if you are willing to crop in winter, you should set your own terms. The customer can and should pay for your shivering and for those clearly elite greens.

What this means for us is that we do not negotiate or bend on prices for our core items, notably mesclun and arugula. While we strive to help our restaurant, grocery, and university accounts make money on all their purchases from us, this doesn’t mean that we are going to sink to the abysmal, economically untenable prices of Mexican or Californian low-end salad mix. This resonates with the observations of Alison and Paul Weidiger in the most recent issues of GFM. Grow an absolutely superior crop, price it fairly, and you should have little challenge in selling it.

So winter marketing is easy. But after years of being a wholesale operation, of being married to the vagaries of the restaurant scene, we have come to treasure our newest marketing approach, a winter subscription service for retail customers. Why? Because in spite of our greens being so clearly superior, in spite of being alone among local growers, the nationwide wholesale trend for organic and conventional mesclun prices is deflationary. Prices are sharply and consistently downward. This can drag down prices and profits for all of us, even those at the top of the quality spectrum. I see no such problems at the retail end. When the flood of $8/case Mexican mesclun hits our region’s wholesale markets in deep winter, I experience a two-week slack period when our mesclun sales decrease by 25% until everyone re-learns the joys of locally grown quality and shelf life. Retail customers, though, treasure anything and all things local. Unlike restaurants, they aren’t subject to the pressures of maintaining really low food costs or to the arbitrary mandates of distant corporate execs who care not a whit for outstanding quality. We will continue to sell to our most loyal, core wholesale accounts, who always want more, more, more. But the retail dollar is both present and appreciative in the winter. So I advise you to feel out your own market. Just remember that you negotiate from strength as the days shorten and your competitors become more and more distant.

I urge you to try a bit of winter cropping. At the worst you’ll have some dead collards and turnip jerky come spring. In the middle arena of success you’ll have generous regrowth of greens with the first real thaw, when neighbors cannot even get in their muddy fields to plant seed. And at the best you’ll come to treasure frost-bit harvesting, quilted coveralls, and a wide-open marketplace. Enjoy!

Brett Grohsgal co-owns Even’ Star Organic Farm with his wife, Dr. Christine Bergmark, in southern Maryland.