May 18, 2007

A unique combination of cold-hardiness, size and edibility, puts five Brassica crops at the heart of our winter vegetable diet: kale, cabbage, cauliflower, sprouting broccoli and Brussels sprouts. We begin seeding Brassicas for late-fall harvest in May, with sowing for the key mid- and over-wintering harvest largely concentrated in June. Here's a synopsis of timing, cultural information, and varietal availability as of May 2007.

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Kale

Kales are the bedrock winter vegetable of our bioregion. �If you have tried kale in the summer and not liked it, you have been eating it at the wrong time of year � it sweetens markedly with the onset of cold weather and farmers who have difficulty giving it away in the summer months can�t grow enough of it for local palates once the chill arrives. This most space-efficient of food crops, highly nutritious and allowing repeated harvests, is far more forgiving of fertility requirements than other Brassicas such as cabbage and cauliflower. Most unusually, our bioregion is particularly strong in locally bred and stewarded varieties � the diversity on offer reflecting our bioregion's place as the de facto heartland of OP kale breeding in the English-speaking world. (A triumvirate of the country�s foremost independent plant breeders eat out of our landscape and the big commercial breeders worldwide give kale very little attention at all � one reason why kales stand at the heart of Territorial Seeds� �locally sourced material.)� We are especially strong in offerings of Russian and Siberian kales (Brassica napus) which are completely ignored by Big Seed and not typically grown in Europe. B. napus kales are better suited to montane soils off the Willamette Valley floor than any other Brassica.

Red Russian kale appears to be the mainstay kale of choice in the PNW. Highly palatable, it can nevertheless fluctuate from year to year in terms of vigor � some seasons it can size up as a picture of robust good health going into a winter: others, it will go into the winter looking somewhat ragged and won�t fully find its feet until the burst of Spring growth lends color, sheen, vitality and mass to its leaves. Some accessions have more leaf than others. Russo-Siberian varieties also include �White Russian�, �Winter Red�, �True Siberian�, �Red Ursa�, �Improved Dwarf Siberian�, and �Western Front�. Frank Morton�s �Wild Garden Mix� (Wild Garden Seeds), originating as a cross between �Red Russian� and �True Siberian�, is a rich, still-hybridizing population affording much in the way of diversity � and genetics for farmers wishing to select strains suiting their tastes and farm environment. All these kales are exceptionally hardy, with Tim Peter�s �Western Front� (Peters Seed & Research) most likely to weather the once-in-25-years-below-zero-sucker-punch, and �White Russian� (Wild Garden Seeds) picking up praise on a year-to-year basis for its relative good looks. B. napus kales are little grown in Western Europe � with, surprisingly, most of their accessions sourced out of N. America - although the Irish Seed Savers are now actively stewarding an heirloom variety, the confusingly-named �Delaway Cabbage�.

Brassica oleraceae kales, sometimes referred to as European kales, are a different species than Russo-Siberian kales, and include the Lacinato/Dinosaur/Nero Di Toscana/Palm Tree kales, Marrow-stemmed kales, variations upon the Dwarf/Vates/Baby/Curled/Scotch kales, �Oregreen� (Peace Seeds) and �Lacinato Rainbow� (Wild Garden Seeds). Alan and Linda Kapuler�s �Steel Green Kale� (Peace Seeds), not yet fully segregated, and available only in small lots, is a striking new kale archetype � a large-leaved, �savoy� glaze kale originating from a �Cascade Glaze Collards� x �Lacinato� cross. �Pentland Brig� has only recently come available again in the US � in impressively stewarded but tiny, expensive lots from Bountiful Gardens. �Green Glaze Collard�, the result of a breeding collaboration between Corvallis-based Carol Deppe, Alan Kapuler and Harry MacCormack, may be one of the finest-tasting leaf Brassicas of any type. In the author's experience, collards (B. oleraceae) are not as hardy as kales.

The slowdown/halt of vegetative growth in the darkest winter months of November through January requires that we grow sufficient numbers of plants to allow for a steady supply of leaves in the period when plant growth slows significantly. This seeding over-compensation for the ecological rigors of winter swings the other way in March through mid-April when kales put on an enormous flush of leaf growth and, soon thereafter, side-shoots, as they begin running to seed. Local farmers have wised up to this tendency and harvest the delicious shoots to sell as �kale raab� or �napini�. Varieties bred specifically for raab production, �Thousand-headed� and �Asparagus� kale, for example, are still available in Europe. Both B. oleraceae and B. napus varieties bred for this characteristic will often have �Hunger Gap� in their names or catalog descriptions.� The sprouting broccolis also fit this archetype. Farms serving Eugene and Portland chefs regard collard as the tastiest �raab� of all.�

While the palatability of locally stewarded material is difficult to beat, B. oleraceae �Winterbor� F1 and �Redbor� F1 are strong winter performers, appearing readier to shake off the rigors of the bitterest winter conditions than most other kales. With a fiercely upright habit, holding the leaves high above the wet ground, with much in the way of air circulation and light afforded, the leaves are easy to harvest. The deep purple leaves of �Redbor�, in particular, lend a strikingly colorful addition to a winter salad, or to a bunch of mixed kale leaves offered at market. The author has no experience with �Darkibor� F1. All three of these F1s are Bejo varieties. (To determine the breeder provenance of any vegetable variety commercially offered in Europe, see the �European common catalog of varieties of agricultural plant species�, on the web.)

Tim Peter�s B. rapa x napus cross of the Russian kales and oriental mustards, an attempt to breed a lighter kale/hardier salad green, and still hybridizing with great abandon in his �Gulag Stars� mix (Peters Seed & Research), holds immense promise for segregating out a mind-boggling array of new crop types, broad leafed Russo-Siberian kales and big, bushy mizunas, for example. They flourish in the outdoors and although extreme conditions will wind the �saladier� of their type, they will bounce back. The Seed Ambassadors Project (SAP) returned from their seed search in Europe this winter with 20 unique varieties of kale, none offered in US catalogs and the majority never before seen Stateside - including five red-leafed varieties. These are largely sourced from German-speaking areas where kale-culture is indigenous. Help with seed increases is sought.

Kale is best sown July � Aug 15, and toward the early end of that window where possible. A later sowing will not reliably size up into a winter. Crops sown in a timely manner, but delayed in planting out in the weeks of mid-Fall when daylight is declining noticeably each day, will rob plants of momentum at a crucial juncture in their development � a week to week and a half delay transplanting into peak growing conditions can make a significant difference in the size of a later sown kale going into a winter. Likewise, many if not most years, warm temperatures into the first rains can lead to intense aphid pressure. Seasonal predation tends to intensify only after Brassicas are sizing up, but if the weather encourages aphids (and snails to play tag-team) earlier and/or longer than usual, transplants in the field will slow. Some Brassicas attract more aphids than others � Brussels sprouts will seem to disappear under the onslaught but, surprisingly, reliably bounce back � others, such as kales, are more inclined to stagger under heavy pressure, especially during their early stages of growth. Flea beetle seems to be the most ravenous predatory danger. This past Fall�s outbreak disappeared as quickly as it appeared � a good thing, because after 4-5 days of sudden, heavy infestation, all our Brassicas were reeling. For this and other reasons, succession sowing into a winter can lend a surprisingly varied difference in harvest maturities. As with all Brassicas sown into the high heat of summer, shade your seedlings/starts. Where possible, avoid transplanting into the most wind-exposed locations: the dessicating affects of a strong, dry, bitter, winter wind can smash a leaf Brassica in two to three hours, where it has breezed through a week of constant subfreezing temperatures.

Cabbage

In European climates colder than ours, cabbage has been the mainstay winter vegetable crop, traditionally grown and 'lifted' for winter storage around mid-October. In the PNW, they will store or �stand� in the field through the winter. But varietal choice is critical. Unlike the traditional �California fresh market� cabbages which more closely resemble a head lettuce, �storage� cabbages are denser, heavier, have more wax on the leaves and are altogether hardier characters. The later-maturing varieties tend even more toward the big, long-legged type, with strong frames and high stems keeping heads off the ground and its associated troubles. There exists greater choice in cabbage diversity than any other winter crop, even as organic farmers locally have come to rely on the �January King� (OG) series, and �Tundra� F1 as their most reliable mainstays. Browsing US commercial, and European catalogs reveals a wealth of choices. Enormous potential exists to explore the staggered maturity of varieties affording constant harvest all the way through fall, winter and very late spring.

We have little experience locally with red cabbages even as it a spectacular addition to the winter palate � fresh red cabbage and carrot �slaw is difficult to beat as a sweet and festive constant of a winter diet. Red cabbages tend to break down more in the winter than the greens. �Rodynda�, a European BD mainstay available from Abundant Life is the most promising OP candidate. �Red Drumhead� and �Marner Lagerot�, also OP, are available organically. �Ranchero� F1 matures on the early side but will hold. �Buscaro� F1, certified organic, can be harvested by October but will stand in the field all winter. �Lectro� F1 is a late season red cabbage. 

Savoy cabbages are recognized by their often blueish, �lacinato-ish� leaves and have traditionally been considered the hardiest of the cabbages, The �Vertus� series is perhaps the most popular savoy in Europe and is available organically, as is the BD �Winterfurst�. A glance at commercial catalogs reveals a cornucopia of savoy hybrids on offer � �Famosa� F1� is organically certified; �Melissa� F1 is more commonly offered. The savoy type has traditionally been favored by French and Italian gourmands, hence specialist seed houses such as Italian Seed and Tool provide a proportionately broader selection.

A common refrain from PNW farmers who are exploring winter cropping is how their transplant spacing continues to widen for most crops, Brassicas especially. Cabbages, in particular, benefit from increased air circulation, and the space to size up. It is surprising how expansive they can get. Spacing is dependent on a variety of factors - especially soil fertility, which can differ markedly from farm to farm. Begin on 24� to 30� spacing and see where it gets you. Leave room for a walk between rows otherwise a traipse down the aisles will leave a trail of brokenness in your wake.

The author trialed 30 hybrid and OP cabbages this past winter, with timing of seeding and transplanting dictated by supporting literature and a leaf taken out of Bejo�s 10-year experience trialing locally, which suggested mid-May seeding and transplanting in early- to mid-July. The cabbages went into good soil amended with chicken manure and produced cabbages far too large (about 8-10lbs) to over-Winter well. An organic regimen? Too much fertility? Later-sown material over-wintered satisfactorily. As with all the heading Brassicas, too lush a plant going into the winter creates increased susceptibility to the elements and disease. Advice for beginners, then: in mid-May, sow cabbages to fully size up for Fall harvest; sow late-May through early-June for mid-Winter harvest, and by mid-July July for over-Wintered varieties harvested up until March.

The picture complicates for more experienced hands working with an array of varieties with staggered maturities, and who have a sense of how long it will take individual varieties of, say, large- or small-headed storage cabbages to �finish� by the time the weather closes in, so that yield and palatability are optimized. One recommended approach: later-maturing or �full-season� varieties can be seeded in mid- to late-May and transplanted by late June; the earlier maturing varieties can be sown 2-3 weeks later, and transplanted in mid- to late-July. Maturities can differ by as much as 120 days. Typically, we aim to have an array of plants maturing by early October through November and then holding in the field to be harvested as needed through February or March, depending on the year. Knowledgeable seed dealers who have seen varieties trialed will be able to speak to the behavior of specific varieties. Shade seedlings from high summer temperatures.

Brussels Sprouts

A defining cold season character, its habit is tailor-made to shed the worst winter weather. We possess little in the way of access to Brussels sprout diversity in the US with most catalogs not even providing a spectrum of early-, mid- and late-season maturities (which can span 100 days). Despite the name, this crop has long been associated with British agriculture � until quite recently the majority of Brassica acreage in the United Kingdom was given to over to Brussels sprouts, even as the varieties commercially grown were largely of Dutch origin. British breeders aver that the precipitous national decline in demand for Brussels sprouts was prompted by Dutch focus on yield at the expense of taste � the bitterness gene got in. Even as Bejo and Syngenta still dominate the global Brussels sprout market, UK breeders claim that their efforts to restore the sweetness of British heirloom genetics (notably in the Bedfordshire series), have restored the crop to its former glory. Browse English catalogs for intel.

Although depth in OP material remains in Europe, barely a token presence can be found hereabouts. �Roodnerf�, and �Long Island Improved� which was the main commercial OP variety Stateside until the more uniform hybrids arrived, are still available. Hybrids such as �Oliver� F1 and �Diablo� F1 now dominate the offerings. Most varieties we have encountered in the PNW appear reliable. However, efforts by local growers to persuade the red Brussels Sprout, �Red Rubine�, to mirror the supporting vernacular of seed catalogs have repeatedly failed. Our suspicions were confirmed recently by a SAP visit with the Swiss Breeder Friedemann Ebner who remarked that even as the variety is still carried by many seed companies throughout Europe and the United States, it has declined over the past several decades and now often fails to produce anything resembling Brussels sprouts. He is attempting to reinvigorate the line. Another red variety, �Red Bull�, also OP has recently come available Stateside and hails from a reputable breeder.

Spaced at 3� the upright habit allows intercropping with a fast-growing crop such as lettuce. Mounding soil up around the stems can reduce the tendency for the plants to topple in the face of exceptional winds in exposed locations. As with all widely-spaced winter crops, as you hoe weeds in early- to mid-August, consider sowing crimson clover. The cover crop will remain stunted through the winter, but in the Spring will produce a beautiful mat which is easy to turn in and break down. The maturity spread between early- and late-Brussels sprouts can be about 100 days. To maximize yield, sow in May to transplant mid-June through early July. The earlier varieties will be ready in September-October, with the later varieties harvestable through February-March depending on the year. June sowings and July transplantings will still produce sprouts, although the plants will be smaller.

Sprouting Broccoli

Cold season broccolis are divided into two types: Fall broccolis harvestable through to the cooler weather of early winter (make the switch from sowing Spring/Summer calabrese varieties to Fall calabrese varieties in mid-June), and over-wintering or sprouting broccolis harvestable in late-Winter through late Spring. No calabrese broccoli (as the broccoli type we commonly know, is referred to in Europe), has yet been bred to be reliably harvestable in PNW mid-Winters: the weather does the florets in. Sprouting broccoli is perfectly hardy, however, and can be left on the plant until it is harvested.

Sprouting broccoli has some potential to emerge as a significant crop hereabouts. In the UK, in particular, in recent years, it has come to dominate the �premium broccoli� market and the four major produce suppliers, who feed Britons 70% of their food, can�t get enough of it. In the PNW, we know almost nothing about it even as its characteristic of maturing a harvest across the entire �hungry gap� through to May, lends it a potentially very useful place in our harvest calendar. Hybrid varieties are almost unknown (even as �Bordeaux�, an F1 from Bejo's English breeding partner, Elsoms, is available organically) but a great deal of variety and strength exists in OP material.

The dominant force in sprouting broccolis is the highly regarded English breeder Tozers, responsible for �Extra Early Rudolph� (harvested Dec thru Feb depending on planting and known to local growers), �Red Spear� (Feb thru Mar), �Red Arrow� (Feb thru Apr), �Redhead� (Mar thru Apr), �Cardinal� (Mar thru May), �Late Purple Sprouting�, �Early� and �Late White� Sprouting varieties. �Nine-Star Perennial� is another white broccoli �harvesting the broccoli spears has the affect of reverting the plant to a �juvenile state�, hence its ability to perennialize (do not leave excess heads on this or any other sprouting broccoli to flower).

The pressure to take sprouting broccoli hybrid are fast intensifying. One of the largest UK supermarkets is pushing aggressively into the American market and will carry the �premium broccoli� phenomenon with it. American growers demand hybrids. Territorial carries some OP material, otherwise source it from the UK. These are very large plants requiring at least 3� spacing. The author hasn�t experimented with timings seeded in different months: July works.

Cauliflower

Pacific Northwestern farmers may know less about winter cauliflower than any other major vegetable crop � most catalogs we are familiar with won�t even separate out Spring/Summer from Fall/Winter varieties: demand for the seed simply hasn�t merited it. But cauliflowers are one of the finest examples of crops that do better in fall and winter than they do in the warmer months. (Winter types require some vernalization, that is, the so-called winter cauliflowers are not ready until the Spring.) Put simply, this is a crop that prefers cold, wet, short days.

The British breeder Tozers, which specializes in cauliflowers, offers a mix of 35 or so hybrid and OP winter cauliflowers which stagger maturities seamlessly January through June. To the author�s knowledge, none are available Stateside and nobody comes close to offering such a selection hereabouts � even to commercial growers.

Locally, we can find �Caprio� F1, an impressive performer coming on in early March from a mid-August transplanting. �Medallion� F1, and available organically, will mature in the second half of March. Purple Cape, an OP purple-headed variety that crops in March-April is available organically. Although cauliflowers are among the most immensely rewarding of crops, growing them is not the easiest of tasks, which is one reason why interest has been largely concentrated among the largest professional growers and why access to varietal choice can be challenging, even for small farmers in Europe. The Europeans do, however, have access to some solid OP varieties. In the US, the material is universally hybrid.

Cauliflowers are considered challenging because they enjoy high fertility and are especially sensitive to stress. If you stress your transplants on an occasion, compost them. Never let the soil they are in, dry. But once over these potential hiccups, they will relish the challenges of the season. Conventional growers will side-dress in early spring but grown in an organic regimen, hybrids or OPs appear able to do just dandily without the extra push. Although winter cauliflowers have been bred to handle harsh weather conditions, some are distinctly less hardy than others. Winter cauliflowers are sown much later than other major Brassicas: transplanting in mid-August is recommended by experienced hands.

For complicated reasons, over-wintering cauliflowers are a particularly challenging plant to breed and also lend themselves very well to the commercial imperatives of hybridization. The disappearance of OP material is therefore especially significant. Territorial has said it is attempting to grow out and reintroduce the OP �Armado� series (dropped by their supplier) over forthcoming seasons, but the breeding and economic challenges to reinvigorating a well-stewarded varietal spectrum of staggered maturities remain immense. The UK appears to be a center for cauliflower diversity, and the small foothold of OP material there is fast evaporating. An independent US-based breeder recommends urgently sourcing OP material out of the UK wherever possible. Otherwise we may simply lose the option of access to this superb OP crop once and for all.

 

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Recommended reading:

Year-Around Harvest: Winter Gardening on the Coast by Linda Gilkeson 2005

Packed with tips on how to keep fresh food on the table all year in the coastal regions of the Pacific Northwest. Includes detailed information on over 30 kinds of winter hardy vegetables, what to grow, when to plant and simple cold protection methods. Chapters on curing and storing fresh fruit and vegetables, managing common pests (organically) and saving seeds.

68 pages 8 1/2 x 11”

The book is $15 CDN so at current exchange rates, Linda makes that about $13.50 US + $5 postage. Linda takes US cheques as she can deposit to a US account. Here is the mailing address for orders:

L. Gilkeson
PO Box 648
Salt Spring Island, BC V8K 2J6
Canada

 

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Nick Routledge manages the nursery for the School Garden Project of Lane County at the Food For Lane County Youth Farm in Springfield, OR.