Perhaps the easiest of all vegetables to grow, you can’t fail with kale! Extremely hardy and well suited to growing in all four seasons, growers in Nova Scotia can harvest kale every month of the year.
Here at Heartseed Farm, we like to make two main plantings of kale: one in early Spring and one in late Summer. We direct sow kale starting as soon as the soil is workable in Spring, usually in April. Although very happy to be direct sown, I’ve recently taken to starting kale transplants in plug trays and transplanting out, mainly to give them a head start over weeds (especially wild radish, which looks confusingly similar to kale when small). Both direct sowing or transplanting work great!
I like to space my plants about 6” apart, with two rows per 3’ wide bed. They can still thrive when planted much more densely, but mature plants will grow large and tree-like if they have the space.
One of my favourite features of kale is that they don’t bolt until their second year. Although a lover of mild, moist weather, Spring planted kale will grow steadily though the summer heat without bolting like many other greens do. Just keep them well hydrated during dry spells. It’s also quite happy to grow in partial shade in the hot summer months, perhaps on the shady side of tall growing plants.
Once the summer heat has died down, I begin sowing more kale for fall and winter crops. Although our big mature kale plants we planted in the spring are still growing strong, I plant most of my kale in the fall to take advantage of empty spaces in the garden left after other crops have been harvested. I like to sow fall kale starting late August, and going as late as the end of September. Under cover in our high tunnel, we can get away with planting as late as mid-October, but plants started earlier will get a lot larger and produce a lot more before winter. Harvests of baby kale can begin as soon as 30 days from planting, with full production starting around 60 days.
By mid-November, outdoor kale plants begin to slow down their growth significantly. Something else happens during the cold weather too, they get way sweeter! Once the leaves are frosted a few times, they produce more sugars as a form of antifreeze. We continue to harvest our outdoor kale until at least the new year, brushing aside the snow if need be.
Grown under cover, in a cold frame or unheated greenhouse, harvests can be extended even further. Although the plants go dormant and stop actively growing in the winter, their existing leaves stay delicious. I find that younger fall-planted kale plants usually overwinter better than larger spring-planted ones.
It’s now February, and as the sun stretches higher into the sky and the days grow longer, life and new growth slowly return to the dormant greenhouse kale. These new leaves are the sweetest and most tender of the year. As the weather warms, these second year kale plants begin the send up tall flowering shoots; they’re ready to bolt. But don’t give up on them for food just yet, the thin florets are even better than broccoli... they’re kroccoli! This is a little-known stage of kale I think more people should be exited for, they’re great raw or steamed, any which way you would eat broccoli.
The florets can be picked and allowed to regrow several times, but because we’re a seed farm we’re really looking forward to letting our kale plants flower and go to seed. The fully flowering plants are a sight to behold, with spires of bright yellow blossoms reaching 6 feet tall. Bees love them. Which leads us to...
Saving Brassica Seeds:
It’s hard to talk about saving kale seeds without getting into other types of brassicas, so I’m going to open this up to be about all the brassicas. We need to know which ones cross pollinate!
Part one - pollination:
The trick to brassicas is to know the latin names of your varieties. Different varieties of the same species will readily cross pollinate, so only grow out one member of each species at a time for seed. Flowers are pollinated mainly by bees, and should be isolated from other varieties by at least 1000’.
The main brassica species are:
-Brassica oleracea: Cabbage, Broccoli, Scotch Kale, Brussels Sprouts, Kohlrabi, many more...
-Brassica napus: Siberian Kale, Rutabaga
-Brassica rapa: Mizuna, Bok Choy, many Asian greens, Summer Turnips, Canola
-Brassica juncea: Mustard greens
There are several other species, like yellow mustard, but these are the most common ones in North America.
So you could grow White Russian kale (B. napus), Calabrese broccoli (B. oleracea), Mizuna (B. rapa) and Ruby Streaks mustard (B. juncea) and let them flower at the same time without them crossing. But if your Broccoli and Kohlrabi flower at the same time you might get some unusual offspring the next year (which are probably still delicious).
At our farm we can grow up to 8 varieties of brassicas each year. One member of each species in each of our two isolated fields.
Another technique you can use to grow more varieties for seed in a single garden, is to co-ordinate flowering times. Time it so that the first variety has finished flowering by the time the second begins. For example; an overwintered Beedy’s Camden Kale (B. oleracea) will flower and go to seed right away in it’s second year, probably finishing flowering by July. Spring planted broccoli (also B. oleracea) will be off to a slower start, and probably won’t start flowering until late summer. As long as they don’t overlap they won’t cross, and you can save seed from both. Just keep a close eye on the plants and nip off any early or late blossoms that might overlap. Know your plants!
Part 2 - Harvesting and threshing
As the plants bloom, spent flowers are quickly replaced by green pods. Over about a month or so, the pods grow and ripen, you know they’re ready to harvest when they turn from green to golden-brown. I like to cut the entire stalk as soon as the pods have mostly turned brown... they can shatter and drop their seeds if left too long.
Spread the stalks out somewhere out of the weather to fully dry and ripen. Once the pods are crispy and burst open easily, they’re ready to thresh. The pillow case technique works especially well for brassicas. To thresh larger amounts of seed, I like to spread the pods out on a tarp, get some music going, and dance on them. Works especially well with a group!
The small, dense seeds are so much heavier than the chaff and broken pods that they winnow very easily. A few passes back and forth between two buckets on a windy day, or in front of a fan, and you have clean seed. Probably seed for several years of growing, and for all your friends, they’re such prolific reproducers!