This is summer cabbage's much hardier relative -- sown later, ready later, and genuinely built to sit in cold ground as a working larder rather than needing to be cut and used all at once. Where summer cabbage gives you a solid few weeks of fridge storage after harvest, winter and Savoy types let the garden itself do the storing, often for months, through weather that would finish off most other standing crops. That's a real advantage for anyone planning past a single season: less depends on having storage space ready, and more of the decision about when to actually harvest can wait until you need it.
Water need
Needs steady water while the head fills out, but established plants are notably tougher and more forgiving than summer cabbage once autumn cold sets in.
Calories at a glance
250 kcal/kg -- low compared to calorie staples like potatoes or dried beans (scale is log-based across all 55 crops in the calculator, staples included, so vegetables don't all bunch at the bottom).
Temperature Range by Month
Month on the bottom, temperature up the side. The pale green background is what the plant can survive at all -- fatal above or below it, labelled directly on the chart where that applies to your zone. The coral band is its ideal range, and only fades in during the months this zone would actually have the crop in the ground -- reusing the exact same sowing/harvesting data as the calendar further down the page. The blue line is real monthly climate data (not a modelled estimate) for a representative rural/agricultural location in this zone -- a small farming town or agricultural research station rather than a major city, to avoid the warmer bias city weather stations have. For the actual verdict on how well this crop does in your zone, see the badge at the top of the page -- that's based on the site's own researched yield figures, not this chart.
Quick Start: Sowing to Harvest
- Sow. Sow later than summer cabbage, typically May-Jun, so plants are well-grown but not maturing before the cold sets in. Check the calendar below -- exact timing varies significantly by zone.
- Transplant & space. Move seedlings out once well-rooted, giving plants about 45cm (18in) of space. Protect young transplants from slugs, which find them especially attractive.
- Tend into autumn and winter. Water consistently while the head fills out, then ease off -- established plants are notably tougher than summer cabbage, and mulch around the base helps protect the root zone through hard frost.
- Cut heads through the winter as needed. This is the real advantage over summer cabbage: rather than cutting everything at once, take heads as you need them across autumn and winter, and let the cold ground do the storing. Cut before spring growth resumes and the plant starts moving toward bolting.
Sowing & Harvesting Calendar
Pick your zone under "Temperature Range by Month" above and this updates too. The Sow row: green is the normal safe sowing window, amber is pushing the season by roughly a month either side with basic outdoor protection (cold frame, fleece, cloche), blue is starting seed indoors or under glass for an even earlier transplant. The Harvest row has two shades: solid green is the crop database's own harvest window, already several months wide in most zones, while the striped tail is the further stretch before a head would realistically need to be cut ahead of spring bolting -- the same "living larder" idea as kale, just for one head per plant rather than repeat-cut leaves. Where that carries on past December, the calendar keeps going into a second year rather than cutting it off.
Calories & Yield
Winter cabbage is a storage crop first, not a calorie staple -- about 250 kcal per kg, the same as summer cabbage and well below true calorie staples. Its real value is being one of the few brassicas that genuinely functions as a reserve rather than a fresh-eating vegetable.
| Climate Zone | Yield per plant | Calories per plant | Viability |
|---|---|---|---|
| Tropical / Humid | 0.8 kg | 200 kcal | Viable |
| Subtropical | 1.0 kg | 250 kcal | Viable |
| Mediterranean | 1.0 kg | 250 kcal | Viable |
| Temperate Maritime | 1.0 kg | 250 kcal | Viable |
| Temperate Continental | 1.0 kg | 250 kcal | Viable |
| Cool / Boreal | 0.7 kg | 175 kcal | Viable |
| Arid / Semi-Arid | -- | -- | Not viable |
| Highland / Alpine | 0.6 kg | 150 kcal | Viable |
Figures per plant sown, from the site's own crop database. Unlike summer cabbage, which is merely "challenging" in Arid zones, winter/Savoy cabbage isn't viable there at all -- it needs a real cold season to work as intended. Subtropical, Mediterranean, Maritime and Continental all tie for the highest yield.
Varieties Worth Knowing
Winter cabbage varieties are bred first and foremost for storage life and cold tolerance. All the varieties below are open-pollinated (OP), meaning seed saved from them breeds true and is worth keeping under this site's seed-saving approach; none are F1 hybrids.
Seed Saving -- Quick Guide
Winter/Savoy cabbage crosses freely with kale, broccoli, cauliflower, Brussels sprouts, kohlrabi and other cabbages -- all one species (Brassica oleracea). It's biennial, so saving true seed takes a two-year cycle.
SERVINGS, NOT DAILY CALORIES This works out plate-sized servings of winter cabbage from your seed during its fresh harvest window only, not your group's full daily calorie needs. For that, use the main calculator.
BIENNIAL Winter cabbage is a biennial, not an annual -- it doesn't produce seed in its first year. Plants grow through year one, a few overwintered plants flower and set seed in year two, and that seed is only ready to sow in year three. If you're starting from scratch with no ongoing seed supply, that means having enough seed on hand for both year one's and year two's sowing up front. Plan for roughly double the seed quantity below if that's your situation.
Estimated for your selected zone above, using this site's own germination, loss and yield figures for winter cabbage -- a helping is roughly what you'd put on a plate as part of a meal with other veg. Treat it as a planning estimate, not a promise.
Storage & Preservation
The garden itself does most of the storing here, but once you do cut a head, winter/Savoy cabbage keeps considerably longer than its summer relative -- typically 4-12 weeks in cool, dark conditions (a cellar or unheated garage), with the longest figures in the coldest zones where it's genuinely grown as a winter reserve crop.
Beyond that, the same options as summer cabbage apply: fermentation into sauerkraut needs nothing but salt and time and keeps for months without refrigeration, and it can be blanched and frozen too, though texture suffers more than fermenting does.
Growing Winter Cabbage Without Bought Inputs
Winter cabbage shares the same pest profile as the rest of the brassica family -- cabbage white caterpillars, flea beetle, aphids -- and exactly which one causes trouble depends heavily on where you are. What works almost everywhere instead:
Floating row covers or fine insect netting are the single most effective input-free defence while plants are young -- they physically exclude the large majority of common brassica pests, with no identification needed. By the time cold weather sets in, pest pressure drops off naturally.
Companion planting helps too: aromatic herbs like dill, oregano or thyme interplanted nearby mask the scent brassica pests use to find their host, and nasturtiums nearby often draw pests away as a sacrificial trap crop.
Crop rotation matters as much as pest defence -- avoid growing any brassica in the same bed two years running. This breaks the life cycle of soil-borne problems like clubroot, which can persist in soil for years without a host to reset the clock.
Mulch around the base going into autumn is this crop's biggest zero-input lever -- it insulates the root zone through hard frost and is a large part of what lets these varieties keep standing (and stay harvestable) through weather that would finish off summer cabbage.
Frequently Asked Questions
How cold-hardy is winter/Savoy cabbage really?
Reliably down to around -4°C (25°F) across the board. The often-quoted -14°C (6°F) figure comes from a single well-documented event -- named varieties (Late Flat Dutch, Early Flat Dutch, Chieftain Savoy) survived one overnight low of 6°F at Acorn Community/Southern Exposure Seed Exchange, reported by market grower Pam Dawling. Treat it as evidence of what the hardiest named varieties can survive under the right conditions, not a guarantee for winter cabbage in general.
Can I really just leave it in the ground all winter?
Yes -- that's the whole point of this crop. Unlike summer cabbage, its harvest window in the crop database already spans several months rather than a single cutting point, and cold ground slows it down enough that you can cut heads as needed through autumn and winter. It eventually stops being safe to leave once spring warmth arrives and the plant starts moving toward bolting.
Do I need to do anything special to get it to flower for seed?
Yes -- the same trick as summer cabbage. A tight head is often too dense for the flower stalk to push through on its own, so cut a shallow cross into the top (an inch or two deep) before spring growth resumes, giving the stalk a route out.
Can I save seed if I'm also growing summer cabbage, broccoli or kale?
Only carefully, and summer cabbage is a special case here: it's the same species as winter/Savoy cabbage, not just a cross-pollination partner, so growing both for seed at the same time is really one crop flowering twice, not two. Both can also cross with kale (oleracea-type), broccoli, cauliflower, Brussels sprouts, kohlrabi and purple sprouting broccoli. Keep varieties about half a mile (800m) apart for home use, or only let one flower per season.
How long does it keep after cutting?
Considerably longer than summer cabbage -- typically 4-12 weeks depending on climate zone, with the longest figures in cooler zones where it's grown as a genuine winter storage crop. It's one of the better brassicas for actually building a food reserve rather than just eating fresh.
Is winter cabbage a good calorie crop for self-sufficiency?
No -- it provides about 250 kcal per kg, the same as summer cabbage and well below calorie staples like potatoes or dried beans. Its real value here is as a genuine winter storage vegetable and vitamin C source, not calories.
How long does the seed stay viable?
Around 4-5 years if kept cool, dark and dry, similar to other Brassica oleracea seed, though germination rates decline gradually each year even within that window. Test old seed before relying on it for a full planting.
Do I need pesticides to grow it?
No. Floating row covers or fine insect netting physically exclude most common brassica pests without needing to identify which one you're dealing with, and companion planting, crop rotation and hand-picking cover the rest for a home-scale planting.