Hard to Save Seeds in cold climates

I was reading the thread about medieval gardens and this is a question I've been thinking about

How was cabbage seed saved in the past in cold climates?
Cabbage isn't hardy enough to naturally overwinter and as a biennial it needs vernalization to flower.

Broccoli (the same species) presumably doesn't have this problem. Maybe there are annual "cabbages"?

Will it really overwinter in a root cellar?  Is that plausible for medieval peasants

I suppose beets are stored in root cellars but this year my beets did not have the shelf life to overwinter, any tips from anyone who saves beet seed? Maybe I had a bad year

Also does anyone have good luck with zucchini? Often zucchini doesn't survive long enough for me, i think because of squash vine borer and drought and the seed doesn't mature.  Maybe there are svb resistant varieties or unaffected locations.  My theory is most all zucchini for seed are sprayed to kill the bugs (something i don't want to do) and the extended season allows the seed to mature, possibly pruning the female flowers because they have a tendency to over produce.

I did get lucky with zucchini once but I'm not consistent. Maybe some varieties are better than others

Same problem with bell peppers, immature seed from over producing plants

Feel free to add any other seeds you struggle saving

I successfully overwintered napa cabbage in an earth-sheltered cold frame. I used a plexiglass pane. Read about it here: https://permies.com/t/234364/creative-cold-warm-frames-earth

Martin Mikulcik wrote:

Will it really overwinter in a root cellar?  Is that plausible for medieval peasants

I believe that the medieval peasants you speak of may have been medieval European peasants with much milder winters than Missouri, rather than medieval Native Americans.

My unknowing guess is that people in colder parts of Scandinavia, central and eastern Europe, might have substituted cabbage for other greens and brassicas such as nettle, kale, turnip greens, etc.

Not only that, but a look on Wikipedia suggests that more common in Medieval times was the non-heading cabbage. For instance, here is an illustration of a cabbage harvest from as late as the fifteenth century:

It is likely that heading cabbage, since Roman times, was known as a difficult to cultivate luxury plant, but it has become known as the cabbage nowadays due to drifting away from the natural ways of doing things.

Collard greens and sea kale are two easier to grow varieties that taste cabbage-like. I have not gotten collards to overwinter, but sea kale comes back every year. I think they are delicious, and a wonderful investment for your perennial veggie garden.

Also does anyone have good luck with zucchini? Often zucchini doesn't survive long enough for me, i think because of squash vine borer and drought and the seed doesn't mature.  

I find that shade and protection is very important for zucchini and other squash. Most people grow squash in full sun which it has been observed tends to kill them. They also tend to prefer immature compost.

It may also be beneficial to try other kinds of squash, like tromboncino, which is a delicious summer squash of the moschata variety which is less susceptible to disease. They are as a rule more ramblers. They also put down roots at the nodes. The variety I have grown is called Centercut squash. Avocado squash is another of this type I have grown. It has been bred as an open pollinated variety but is more commonly available as a hybrid.

I hope this advice helps!

I've become quite suspicious that some of the seeds, both commercially produced or saved from fruit and veg from the shop/supermarket have had hardiness bred out of them, and some even like canola, been genetically modified so that saved seed won't ever grow.  
I did manage to grow capsicum from a very ripe red fruit, and it over-wintered in the garden - second year fruits really small.  Broccolini  produced seed from purchased seedlings, but then no action when they were sown the following year, although the plant did grow again from the  stalk I'd left in the ground.  Same with the silver beet (Swiss chard) - practically a forest of that.  It doesn't do well once the weather warms up.

M Ljin

I have had chinese cabbage set seed before, i can't remember if it somehow survived the winter or bolted from summer heat, i don't grow it much myself.  I believe it bolted in summer and reseeded itself in spring

I guess i always thought sauerkraut had a long history in very cold Slavic countries.  Maybe it was not made of cabbage in the modern sense.  Do you know where i should start looking for an annual brassica for sauerkraut?  I don't need pure white tender leaves.  Are non heading cabbages still a thing?  I bet they fair well against cabbage butterfly

Sea kale is interesting. Collards are also biennials, but why isn't broccoli (theyre all the same species), must be like facultative barley.

I have tried the other zucchini and they are good, but just as tricky to get mature seed.  Maybe thats the nature of zucchini.  Bound to overproduce and need flower pruning or they have too many fruit to harden any off.  I will give part shade a try.  I bet the shade helps with the drought stress.  It doesn't help i don't water much

I suppose i could just eat immature butternuts

Thank you for the advice

I gave up on non green cabbage types. They need more lime/clay. Perennial kale for me. Don't know if it will ferment nicely. Doubt it will be like sauerkraut. Lacks rubbery texture, but who knows.
Zucchini I never managed to grow until I got a lot of varieties send to me in the seed box of GoingToSeed. They were much bigger than normal zuchinni seeds.. I grew them in unmatured cowdung.
There is so much variety in varieties that it really pays off exchanging them, whatever problem you're facing with veggies. Growing genetically diverse veggies selects those that love your specific conditions. All survivors that contribute pollen go into next years seed. Growing those out will be descendants of the winners. If those keep crossing over a good few generations you'll get a super adapted strain. That's how heirlooms got developed traditionally. But because they are frrom the past heirlooms are I'll fitted to our modern diseases.
Another advantage is today's climate is not stable, late frosts can kill off crops, sudden heat waves and unprecedented droughts. Growing diverse varieeties takes care of weather weirding. And in good years all plants survive you can select biggest/most interesting looking plants. I some fruit early, others late, you stretch your season that way.
And differing colors looks great and is even more nutritious.
Seed savers sticking to mono varietal growing are missing out big time.

As far as "annuals/biennials",  I save everything except carrots, ginger (not a seed), and corn. I don't save every seed every year. For instance, I save watermelon seeds once only and use them for several years combining with purchased seeds. I don't have enough plants to save from and not ready to landrace watermelon between the clay and the bears.

For corn, I cannot grow enough plants to prevent inbreeding depression. When I did attempt cabbages (which never grew...), I was not planning to save seeds. In my garden, these things sort of worked themselves out. If they are too hard to get to maturity to save seeds, unless I am willing to repurchase yearly, I am not going to keep trying.

This also limits the number of varieties for me. Landracing helps a ton. To clarify, I only grow one variety for species of squash, brassicas.

I have had cabbage naturally overwinter in Zone 4, for what it's worth.

It may have been somewhat mulched with leaves, and certainly was snow covered.

I'm going to try spigariello leaf broccoli this year hoping it will be an annual for me, and I'll try sea kale as well hoping it will overwinter.

Has anyone any experience with Portuguese cabbage/kale tronchuda? Some say it's an annual but nobody with real experience and i suspect it's a mistake

Seems odd to me that you can't get zucchini to seed in Missouri. I have not had any trouble with several different varieties in Northern Illinois, much farther north. I just let a few fruits stay on the vine until just before the frost. Then pick and store in the garage until spring, split them open and collect the seeds.

I lost my watermelons over the last few years. Watermelon will grow here but every few years the weather is bad and you get nothing. This happened two years running and I used up my last saved seeds in 2025 and got nothing. I had been growing them since about 2008 so a bit sad to lose them.

Costata Romanesca is a very reliable zucchini variety that makes delicious fruit. I believe they will ripen one fruit at a time unless picked immature. Maybe try some different (older) varieties?

I haven't tried many varieties, only tried to save seed twice.  It's hard to keep a zucchini alive till frost, maybe I'm doing something wrong.  Do you irrigate? What about vine borers?  Maybe being farther north is a benefit, because the summer heat and drought is rough on them.  I'll try to irrigate this year and part shade.

Does the seed develop further in the fruit over winter?  I cleaned some fruit that was basically like an acorn squash, i was confident would be good and only a handful of seeds were mature.  I forgot the variety, black beauty comes to mind

Thom do you have a favorite variety?

M Ljin funny you recommend costata, driftless seed company says "Unlike other zucchinis we produce for seed which can set multiple fruit with good seed yield in each, Costata Romanesco seems to only want to set seed in one fruit per plant, making it much more expensive to produce".

Maybe it's adapted for us southerners

No idea what zucchini varieties I have. Seeds originally were whatever was on the store shelf years ago.

I do think the seeds continue to ripen inside the stored fruit, but I have not tested it so it might be my imagination.

Martin Mikulcik wrote:Has anyone any experience with Portuguese cabbage/kale tronchuda? Some say it's an annual but nobody with real experience and i suspect it's a mistake

Tronchuda is annual according to every portuguesa I've asked about it but I suspect they just mean they grow it as an annual and harvest them as a complete unit instead of leaf by leaf like they do with galega. I think it needs to overwinter to actually produce seed.

It looks like this and is the one that people will grow as a bulk crop to feed themselves and their animals.



The perennial one is couve galega which is a tall kale-like cabbage with leaves like collard greens. This is the one I grow.



It will live for several years if you keep taking the buds off, but I've been working on a truly perennial strain that will survive several years of flowering. It's grown near the back door of every rural household for picking at any time there's nothing else to eat, all year round, or when the weather is bad and you don't want to venture out too far, or when you need a couple of leaves to take to the outhouse with you.

However, I've seen seeds being sold by people who obviously don't realise they are very different plants and have muddled the names up, and I've seen permaculture books by quite respected authors also muddling them up.

Martin Mikulcik wrote:

M Ljin funny you recommend costata, driftless seed company says "Unlike other zucchinis we produce for seed which can set multiple fruit with good seed yield in each, Costata Romanesco seems to only want to set seed in one fruit per plant, making it much more expensive to produce".

Maybe it's adapted for us southerners

They do focus on one fruit, and specifically they want the single fruit to be as gigantic as possible.

Once a delicata crossed with a Costata Romanesca zucchini, and the result was a volunteer growing from a rotten immature delicata. This volunteer grew an enormous climbing vine with two enormous hanging zucchinis (Costata Romanesca is a bush variety). It was surprisingly late too. The zucchini kept at room temperature for months, and was still soft-skinned and tender after all that time.

I've had some luck in zone 5 with Georgia Collards. I was down to my last pinch of seeds (the pack lasted me over 10 years!) so I really wanted them to get through to the next year and flower. Instead of pulling them up at the end of year, the tops were chopped off and the stems left in and covered by the Autumn compost, manure and leaves. Next spring they sprouted like crazy and flowered well.