Organic Gardening & Farming, Plants

Breeding Winter Hardy Kale & Collards, Year 1

Biennial plants such as kale and collards produce seed in their second year. That means they won’t produce any seeds if they don’t survive the winter, and neither of these plants is reliably hardy in my Zone 6a garden in Indiana. Most Northern seed keepers dig up their plants every autumn and overwinter them in a greenhouse or root cellar, then re-plant them in the spring for a seed crop. I don’t have a greenhouse or a root cellar, and I’d like to try breeding a hardy strain of kale by selecting seeds only from the hardiest plants that survive winter in the ground. I’m sure I’m not the first person to have this idea, but I do think there’s room in the world for more strains of northern-selected seeds, and for locally adapted seeds in general. Plus, it just seemed like an interesting thing to try.

So I left all my kale and collard plants in the ground over winter. I did place a covering over them during the very coldest weather (we had pipe-burstingly frigid temperatures around Christmas), but I mostly left them uncovered to experience winter. Even if they look dead up top, some of the plants maintain living roots beneath the surface. In the spring, the plants that survive send up new leaves and then flower stalks. All of this did happen for about 1/3 of my plants!

I am pretty happy that I got this far on my first try. However, I ran into a few problems that prevented me from actually saving seeds this time around. I think there’s value in writing about what went wrong, so that other growers and seed keepers can learn as I learn. Read on to share in my findings from this year.

Just Pick One

I had several varieties of kale and collard greens and broccoli all growing in my garden. All of these plants are the same species, so they can all cross pollinate. I didn’t want to grow a broccokaleard (although maybe I do, now that I think about it). I expected I could maintain the individual varieties by excluding pollinators from certain plants using floating row cover fabric, so that only one variety of blooms was available to pollinators each day. This turned out to be too much for me to manage in the spring, since there are so many other demands on my time during that season. It would be much easier to simplify and fully focus on one variety. Next year, I plan to focus on Blue Curled Scotch Kale, since that’s my personal favorite. That will also allow me to grow more plants of that kind, and it should also help with the next problem.

Timing Is Vital

I had lots of plants that survived the winter, to varying degrees. There were only a select few plants that really looked good, maintained their leaves throughout winter, and were ready to bloom right away in the spring. Those were the plants I really wanted to save seeds from. However, I only had about one plant from each variety that looked really good after winter blew over, and one plant is not enough to produce a seed crop. There were a number of other plants that had living roots and part of a living stem, and still more that had living roots but a totally dead stem. Each of these sets of plants flowered, but each group flowered at a totally different time, the ones with the most winter damage taking the longest time to flower. I tried cutting back the bloom stalks on the earliest blooming plants to see if I could get them to flower again in synchronicity with some of the delayed bloom plants. They did flower again, but they never all bloomed at the same time. I think having more plants of one kind will increase the chances that multiple plants really thrive over winter and bloom concurrently.

Make Room

Eventually, after cutting back bloom stalks again and again, I found myself in late spring. I really needed to pull the plants up to make room for this year’s garden, and I just couldn’t wait any longer. Next time I try this experiment, I’ll need to budget room in the garden for it. Maybe I will let my seed project keep the garden bed until July next time, and then I can put in a fall crop of carrots, radishes, or rutabaga when they’re finished. This year, I had spring seedlings in the wings that were eager to occupy that space.


I’m really glad I tried this experiment. I had fun with it, I learned something new, and I am excited to try again next year. To me, that’s what gardening is all about! Do you save seeds from any of your favorite plants? Tell me all about it in the comments!