Brassicas Rule! A Fall Planting Guide
Listen… do you hear that? It's your kale talking. It has really been loving the extra attention that you’ve been giving it, and as a result, it's inviting you into the garden to take a few leaves. It's OK, it’s happy to give them up. Just be sure to share some love with your broccoli, cauliflower, cabbage and Brussels sprouts. And don't forget the collards…they'll get jealous.
One of the bigger vegetable groups that I grow (outside of potatoes and their kin) is the Brassica family. They have lots of players, and many (like kale) can be grown at almost any time of year on a farm or in the garden. On my farm, we start by planting radishes (from seed) and kales (from transplants) in early spring. Then we throw some Asian greens (Tokyo Bekana is my new fave) into the mix later in the spring. Finally we move to the cabbages, broccolis and cauliflowers (all grown from transplants) for the fall.
Part of our strategy is a function of real estate; we are able to plant every available bed to cold-hardy crops like radishes and kale very early in the season. Then we have to wait for a few successions of these and other crops to finish out before we plant brassicas again. For this reason, the broccoli and cauliflower that I plant is all geared towards fall production. One of the advantages of this is that fall really is the golden season for lots of these crops. Cooler days and nights are perfect for forming beautiful domed heads of broccoli, jaw-droppingly pretty cauliflower, and tight, dense heads of cabbage. Exciting to think about all those pristine vegetables, isn’t it?
Starting Brassicas for Fall Production
In more Northern regions like ours, now is the time to be seeding these fall players for transplant in a few weeks. On our farm, we always follow our early peas with our fall crops. The peas are usually done at just the right time to till in and plant brassicas, and the fall crops get an extra boost of fertility from the plowed-down pea greens. I have been growing Belstar F1 broccoli for years now, and it loves this schedule, and makes crowns that make me feel like a real farmer. It will be forming heads late enough that I don't see a lot of side shoot production, which is why I plant a few successions. The harvest window for Belstar F1 is about 10-15 days, so if you stagger your plantings by two weeks, you should have a continuous supply of broccoli through the fall months.
The Fall Advantage
Most of the major pests that go after these plants in the spring will have cycled out for the fall planting. In our spring plantings, we don't put any brassicas out without immediately covering them with remay. Our two big spring pests, flea beetles and cabbage worm, can't do their damage if they can't get to the plants. Flea beetles aren't generally a problem for us from midsummer on, and cabbage worm usually does its worst in the spring, and typically won't bother us later in the season. Not having to keep the late-season plantings covered allows us to keep them well-weeded and clean. We weed a few times and then they have enough leaf cover to crowd out any weeds trying to take hold.
We often side dress our kales and Brussels sprouts with compost later in the summer. They have been working hard since spring, and need to carry on through late fall, so they really benefit from the extra food. Putting some extra time and inputs into these full-season crops can yield a big payoff. As a group, brassicas are super hardy, and can take some pretty cold temperatures without losing eating quality. A few years ago I had a broccoli crop that was moving really slowly in the waning days of autumn, but I let them grow into late November. I ended up covering some of them with row cover, and one night they got down to 22 degrees under the Remay. When they thawed out, however, they were absolutely beautiful, and I sold every crown at a late season market. They were also delicious, having gotten sweeter from the cold temperatures.
Other Crops – Roots
So now you’re probably wondering what other crops we’re growing in the fall and how we do it. You can direct-sow fall carrots, parsnips, beets, turnips and rutabagas through the end of July for harvest into late fall (or even overwintering if your winters are mild enough). The trick here is that these crops like to germinate in cool soil. Try using cardboard or shade cloth to cover the soil for 3-4 days before seeding carrots and beets – this will shade the soil, cooling it and helping to retain moisture. If you live in a very hot, dry place, plant your seeds in a little trench where water will collect, water in well, then re-cover them with cardboard or shade cloth. Check them every day and only remove the covering once they’ve germinated.
If possible, plan to irrigate or sow seeds just before a period of rainy weather – this will also help cool the soil and improve germination rates of midsummer plantings. If you grew spring crops in these beds then you will want to rotate through different plant families – for example, if you grew spring mustards in a particular bed, try to grow fall carrots or beets there as opposed to broccoli or cabbage. Ideally brassicas should only be planted in the same spot once every three years, however this may not always be possible. Rotating your crops will help avoid a buildup of pests or diseases particular to one plant family, and will also help balance the nutrients beings used up. If you can, amend the bed with compost if you grew spring crops in it – this will help restore any nutrients that have been depleted.
Greens & More
Later in the season, from mid-August to September, you can plant more short-season, cool weather crops like lettuces, spinach, mustard greens, Asian greens, arugula, scallions, and radishes. The same principles used for carrots and beets (above) should be used for these crops. They really like cool conditions, and will be a lot happier going into soil that has been cooled off if it is still very hot in your area at that time of year. Have hoops made of galvanized metal wire and row covers at the ready for when frost threatens. Some of these crops – like radishes and scallions—are very cold-hardy and can withstand a light frost; however most will benefit from some protection.
Here are some more resources for planning your fall harvest. For a general overview of how late you can plant various crops depending on your first frost date, check out this helpful succession planting chart published by the Farmer’s Almanac.
To determine the first frost date in your area, just type your location into the Farmer’s Almanac frost date calculator.
For more regional growing information, check out these guides published by Ag Extension.
And take a look at our many previous articles on fall and winter growing:
- Don’t Forget About Fall! Seeding Now for Autumn Abundance
- Planning for your Fall Crops – Start now!
- Tips for Planning Your Winter Harvest
- Frost Tolerance in Vegetables
- Mini Heads for Season Extension and Major Value
- Winter CSA Basics: Bringing the Seasons into Balance
- Growing and Storing For Winter Markets
- Winter’s White Gold: Planning Ahead for Belgian Endive Harvest
- Winter Farming in Southwest Montana