The Extreme Gardener

Experiments in permaculture and
other gardening adventures in northeastern Vermont

Overwintering cabbage

October 26th, 2008

I worry about brassicas and onions. They are such important plants, and very few seed savers are working with them. The rate that the commercially available open pollinated varieties are disappearing is really scary. Brassicas and onions can be pretty fussy to grow seed and maintain purity, so it’s not hard to figure out why seed savers grow lots of tomato and bean varieties, but very few cabbages for seed.

I have a couple of good strains of kale I’ve been working with for about 10 years, and have had some success growing broccoli seed, though not consistently. I haven’t had any success with growing seed from heading cabbage – I can’t seem to maintain the plants in a root cellar over winter in good enough condition to get healthy seed the next year. So, I have had a strong interest in finding a hardy enough heading cabbage to overwinter here in the garden. The bummer is, I’ve finally found one, and now I can’t find a source for the seed in the US or Canada. The most recent edition of The Garden Seed Inventory has it on the no longer commercially available list. Yet, there seem to be plenty of commercial offerings for this variety in the UK.

cabbage July 2007

Cabbage Offenham July 2007. It was the only seedling that survived the first winter from an in situ sowing August 2006. The plant yielded one nice, sweet, medium sized conical head in October 2007. (Sorry, I forgot to take a photo of it.) The heads have a strong resemblance to Early Jersey Wakefield, though Offenham plants are larger framed.

cabbage July 2008

July 2008, the plant had survived a second Vermont winter with no protection. I was impressed. I then expected it to bolt in 2008, but low and behold, it made 5 or 6 lovely little pointed heads this September and October, and it is continuing to throw shoots up from the roots and stalks.

cabbage Sept 2008cabbage multi head detail

Over wintering cabbages are also called spring cabbages. In warmer climates than ours, they are sown in August for heads in the late spring, and the smaller heads cut again in the fall. So, I’m wondering if I hadn’t cut the first head (in Sept. 2007) if it might have sent up a seed stalk last spring. It’s kind of a moot point because there’s only the one plant. (I like to have at least 6 plants for brassica olearica seed production). One way or another, I’ll have to find some more Offenham seed to plant next August…

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18 Responses to “Overwintering cabbage”

  1. Jeremy says:

    I’ve never had much problem growing onions for seed in the past. I generally lifted them and stored them overwinter and then planted out about 16 or 20 plants in the spring. The big problem for me was cleaning the seed; for some reason the dust was far and away the most irritating I ever dealt with.

    Cabbages are, I agree, much more difficult, especially if you cannot over-winter them in the ground. That was not something I had to worry about, as the ones I was interested in all over-wintered fine. Is there no way you could use a polytunnel or similar to leave them in the ground? And grow more than six, if you can. Thirty-six is more like it. You’ll get pounds of seed, but it stores brilliantly and you can spread it around.

  2. Søren says:

    You could consider propagating your Offenham by cuttings the next years, until you can grow more plants and have them through the winter.

  3. the extreme gardener says:

    Jeremy – yeah – the onions are easy enough to overwinter. The problem I have with them is fungal disease and the narrowness of what’s available commercially here in the US for a long day length storage onion. I’ll post more about my onion project soon.
    What cabbage varieties that you have grown seemed to be the hardiest? It would be great to be able to have 3 dozen or so parent brassica plants, but unfortunately, I just don’t have the space. The polytunnels would probably work, but I’m terribly fussy about using plastic and purchasing garden fixtures. I’m not a total luddite, but in my gardening and breeding projects I am always looking for plants that require as little input as possible.

    Soren – they do look like they would sprout from cuttings well. Yesterday I covered the plant with a deep leaf mulch, which may help to keep it through the winter without rotting – and hide it from the deer.

  4. Ottawa Gardener says:

    I have had mammoth red rock cabbage come back in my garden after cutting for two years but it has yet to form a seed stalk. I leave it there waiting to find out what happens. If you really only need to save 6 plants (I thought it was more for brassicas?) then I’d been willing to give cabbages a try. As it is, I’m trying kale. We do have good snow cover here most years though the ground freezes solid. Also I seem to recall that onion self pollinates. If that’s so then maybe I could only grow one variety or cage it? They, at least don’t take much room to grow! At the moment, I’m only working on vegetatively propogating alliums like shallots.

    (How do you make cuttings of cabbage? – intriguing)

  5. Patrick says:

    Sending seeds into the US seems to be no problem again. If you can’t find a UK seed company to send you some, I’ll be happy to forward a packet of seeds to you. I’m travelling to the US in December, and I could hand carry it through customs with some other seeds I’m bringing if you like.

  6. the extreme gardener says:

    Ottawa Gardener – Thanks for the tip on Mammoth Red Rock – I’ll have to try it and put it to the extreme gardener torture test. I love getting info from other gardeners about hardy varieties! I think you’re a little warmer than we are, but pretty similar – frozen ground with reliable snow cover. I’ve gotten good seed crops for brassicas with just six plants, but more is better, if you can. It helps if the parent plants are all big and robust. I plant them in blocks in beds so the plants are branching into each other when they bolt.
    Onions are insect pollinated, and it’s quite a bit more difficult (at least for me) to get good seed from them. The seed also doesn’t remain viable for very long at all – I don’t trust any allium seed that’s more than 2 years old.
    Growing just one onion variety is probably the best thing to try at first, assuming you’re not within a mile of anyone whose letting their onions or shallots bolt. They can be hand pollinated, but that’s a tedious labor of love.

  7. Ottawa Gardener says:

    It is good to correspond with a gardener in a similar climatic zone (I’m Can. Zone 5a / US Zone 4a though I feel in the city I can get away with more than my zone suggests). Are you on Homegrown Goodness the plant breeder forum? http://alanbishop.proboards60.com/index.cgi

  8. the extreme gardener says:

    Pardon the tardiness of my replies – for some reason our spam filter started blocking the e-mail from this blog.

    Thanks, Patrick for the offer of seed procurement – I’ll send you an e-mail.

    Ottawa Gardener – thanks for the Homegrown Goodness link – I hadn’t come across it before – it’s great! Once the ground freezes, I’ll have more time to explore it. Last week was excellent for gardening. Several days I was able to work bare handed weeding perennials – one of my least favorite tasks, but much more pleasant without November’s typical bone chilling cold soil.

  9. Doug says:

    Hello!
    Great site. I was wondering if anyone has found a source for the Cabbage Offenham. I would like to try onerwintering some here in Idaho. Is it possibe to order seeds from England?

  10. the extreme gardener says:

    Hi Doug! You could try http://www.gourmetseed.com and contact them about it. They don’t list Offenham this year, but I originally purchased my seed from them. (Maybe they could do a special order?) They import a lot of fascinating European varieties, and the seed is very good quality.
    I organized my seed stash this past winter and found enough Offenham seed to plant for August ’09, but please let me know if you can find a US vendor, I’ll certainly buy some more and I know of quite a few other US and Canadian gardeners who want to get their hands on this.
    It’s a little early to say for sure, but it looks like this plant survived its third winter here. I hope to follow up on Soren’s suggestion and take cuttings.

  11. Doug says:

    I just received 30 grams of Cabbage Offenham 2 Flowers Of Spring and 30 grams of Cabbage Offenham 3 Wintergreen from England. Moles Seeds in Stanway, Colchester Essex, will be happy to send it to U.S. Contact Robert Aldsworth, Moles Seeds. UK
    I can’t wait to get them going and see if I can overwinter for seed production here in southern Idaho. My goal is to be self sustaining for all my favorite veggies.
    Thank you for your infomative article on overwintering cabbage. I was not aware of the different cabbages that will over winter and produce seed until I read your site.
    Another varity for consideration would be January King. I have some seed comming from West Coast Seeds in Canada.
    Wish Me luck! 🙂
    Thank You. Doug

  12. Doug says:

    Oh, By the way, I also ordered cabbage Filderkraut seed from Robert at Moles Seeds. It is comming in a separate package with another Offenham variety. They had to order the Filderkraut in.
    Do you know anything about Cabbage Filderkraut and how cold hardy it is? Will it overwinter in your neck of the woods?
    All I can find out is that it is the cabbage of choice by the Germans when they make saurkraut. Thin, tender leaves makes all the difference. It is also a beautiful plant. Large and pointed. Any info would be greatly appreciated.
    Thank you Doug.

  13. the extreme gardener says:

    Good work Doug, and thanks! I’m headed over to Moles http://www.molesseeds.co.uk .
    The seed I have is Offenham 3. Are you going to do multiple sowings? It’s normally sown in August, which is what I did. I’m wondering if the time of year it’s sown has an effect on whether it bolts or stays in a leafy (perennialish) mode. It might vary with climate or latitude (day-length) (or both) or?…
    I have grown January King (sowed in May-June), but have not had it survive the winter. Maybe I’ll try sowing some in August.
    I’ve not grown Filderkraut, though it caught my eye in the catalogues – I love the extreme conical shape, like an elf’s hat.
    Moles has good variety comparison info on their website, and Wheelers Imperial looks like another good overwintering cabbage candidate.
    For a very cool discussion of perennial cabbages check out this thread http://alanbishop.proboards.com/index.cgi?board=brassica&action=display&thread=1930

  14. Doug says:

    I have my home garden, two different plots at two different friends farms and the lot next door. I am going to start seedlings tomorrow, and every two weeks from there on out. I am going to plant once a month, 20 plants each time, until about 2 weeks before the first frost. Prior to the first frost, I, unlike your extreme practices, :), will construct low pvc type hoop frames with greenhouse covering over them. I will tuck them in with shredded straw up to their chins and crawl in among them twice a week to add a little water if needed and sing them Irish folk songs.
    I want to grow one plot with the different types and go extreme. No cover or anything else…just to see what will grow to seed or not.

  15. Doug says:

    BTW, Home Grown goodness is a good site. Believe I’ll hang around in the shadows and learn something. I am really interested in doing some crossing. I am reading Breed Your Own Vegetable Varieties by Carol Deppe. Once I figure out which ones will do the best in our cold winter, I may breed them to get a cabbage that will grow in my refridgerator. Just open the door, pull some leaves and pop them into the white bean and sausage soup!

  16. the extreme gardener says:

    Yer hardcore Doug!
    If you’re thinking about dong some crossing, you might want to check into couve tronchuda – we have a thread going about that at Homegrown Goodness in the brassica section. Anyway, it’s a more primitive b. oleraca type with a lot of interesting genetics and adaptability (heat, cold, salt). Very good eating too. I’ll post more here soon.
    I look forward to hearing about your experiements.

  17. Doug says:

    I have Couve Tronchuda I bought from Redwood seeds. They are about 2 to 3 inches now. I read on Homegrown goodness where you stated that Redwoods Tronchuda is a generic type. Is it not the real deal? I was considering crossing it but I also understand that the cold hardyness is lacking.
    Also, let me know if you are planning on buying Offenham seed in bulk from England or just need a smaller amount. When my other package gets here I can send you some of each. If you want to trade I could use some cold hardy Chicory…anything cold hardy. Do you have an abundance of those pole beans?

  18. the extreme gardener says:

    The one Couve Tronchuda that Redwood City Seeds is offering now is Portugesa, which is, I guess you could say, the standard variety – It is Portugal’s national vegetable. Redwood City used to offer 5 or 6 other varieties some of which form small, loose heads and have more pronounced ribs and different coloring, etc. US importation restrictions since 9/11 have made it not cost effective to import all the varieties, because there is not enough demand. The Portugesa is indeed the real deal – it is less refined (more diverse) than the other varieties, and would be an interesting parent. The tronchudas I have grown stood up to the cold well, but did not over-winter. I think some might given good size population… I just really love some of the heading varieties – they are very beautiful and tasty plants

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