Summer! Isn’t it wonderful that it’s finally here? For the last several months, we have been working toward this time – when we are harvesting all the crops that make market farming what it is – tomatoes, peppers, beans, squash, okra – wonderful stuff! And now it’s time to plant for fall.

Fall!? We’re just really getting going on summer! But fall is a great growing season, and for brassicas, an easier season than spring in much of the country. Our springs here in southern Kentucky are usually very short, segueing into hot, often dry summer by early June. Brassicas, being cool-weather crops, don’t take kindly to that. They get hot, bitter and bolt. Brassicas are a very large family encompassing a lot of different vegetables, and most are good bets for fall. In this column, we’re going to talk about our top three – broccoli, cabbage and cauliflower. We also grow them in spring, but fall is a better growing season for us, and cauliflower, which is all but impossible in our normal springs, does beautifully in fall.

Long before these fall brassicas are ready to harvest, a lot of market growers will be looking with fond longing toward frost, and a reduced workload. So why deliberately grow a crop that ensures the continuation of the workload beyond frost? The best reason is the continuation of sales and customer contact. But another compelling reason is the pure joy of growing in the fall. Weed pressure, insect pressure, miserably hot harvest days – all diminish in the shorter, cooler days of fall. It is also a great feeling watching those beautiful plants continue to produce after cold temperatures have turned your tomatoes to mush. Where we live in Zone 6b, we can often have broccoli through Christmas – that’s exciting for us and our customers.

Simple season extension methods can help also. Although the space in a high tunnel is really too expensive a space for cabbage, cauliflower and broccoli, and in our experience, they don’t do very well there anyway, row covers outdoors can make a huge difference. In December 2003, we were on a farm tour at Nicholas Donck’s farm outside of Atlanta, Georgia. At the time, he had some broccoli growing under row cover, and some growing without row cover. The uncovered broccoli looked a lot like ours – obviously cold damaged, although still saleable. But the covered broccoli had no damage, and was still producing very well. We plan to cover our broccoli this fall and expect to have better, longer production. If you are interested in summer production of broccoli in hot summer regions, we have successfully grown it during the summer, under lightweight row cover installed over hoops. It did very well, had reasonable quality, and no worm damage. We decided it wasn’t cost effective for us during a time when we had so much else to harvest, but that could be different in your operation.

Start with transplants
As with many vegetables, fall brassicas are best grown as transplants. You have control over many factors that make a large difference in the quality of the plant. We use 608 (48 cell) inserts for brassica transplants. We aim for a 6 week transplant on the chosen transplant date. For us, with a first frost date the middle of October, we want to have transplants ready the first of August. So seeding the flats needs to happen about the middle of June. Each farmer can adjust that seeding date accordingly. (Be sure to add 10 days or so to the DTM (days to maturity) to adjust for the shorter days of fall when figuring the seeding date.) After seeding the flats, we cover and refrigerate them 24-48 hours – no longer, or they’ll germinate in the refrigerator. We find that with our very warm nights, the short cooling time greatly enhances germination percentages.

Once germinated, we put the flats in full sun. In past years, we have used greenhouse benches set up in our back yard, close to a water source. The two largest issues are keeping them watered – usually at least once a day – and watching closely for cabbage pests. The Imported Cabbage Worm butterfly is very active in mid-June on our farm, and the caterpillars can devastate a flat of seedlings faster than you can imagine. Last year, we put the seedlings in our greenhouse, which helped. We didn’t have as much problem with the cabbage butterfly, but some still entered through the vents and we had to be watchful for them.

At six weeks, the plants are ready to be planted in your soil. Remember, brassicas are cool weather crops, and August is still really hot for most of us, so we need to do our best to keep them cool. We use drip irrigation to keep the soil moist which helps with the microclimate around the plants. A cooling mulch, such as hay or straw can also be helpful to cool the soil.

Soil fertility is an important consideration with brassicas. Most brassicas are pretty hungry plants. We have seen N requirements ranging from 75 pounds per acre to 150 pounds per acre, depending upon crop. Broccoli seems to be the most N dependent. We typically broadcast our 3-4-3 pelleted chicken manure product at the rate of 10 pounds per 100 sq. ft. (which is the equivalent of about 125# of N per acre) and till it in before transplant. We want these plants to take off, and provide the nutrients for them to do so.

Brassicas have a lot of insect enemies and when growing them in late summer, you’ll have to be vigilant. The two most readily identifiable are imported cabbage worm and cabbage looper. We have the ICW, but not the looper on our farm. Just in case you don’t know, the ICW adult is a very pretty white butterfly with black dots on the wings. If you watch it land on a plant, then look where it landed after it leaves, you’ll see a small elongated light-yellow egg. That egg hatches in 3-7 days into a very small caterpillar that grows FAST and will eat your crop for 10-14 days before pupating. It is velvety green with a yellow stripe and can ruin a crop very quickly if not stopped. The cabbage looper adult is a moth active at night. The larva is distinctive for its looping motion as it crawls. We also often see army worms in the fall, and they, too, can ruin a planting very quickly.

Fortunately, we have a great tool for stopping these pests in their tracks – spraying with BT (Bacillus thuringiensis). Once the larva has eaten the leaf with BT on it, it stops eating quickly, and dies in 24-48 hours. However, it does have to be eaten to work, so good leaf coverage is important. Since brassica leaves have a surface that is repellent to water, be sure to add a sticker/spreader to the spray. Also, as with any control, the targeted insect can develop a resistance to BT over time, so spray only when necessary – when you see the first damage, rather than on a schedule. If you are certified organic, or you don’t want GMO’s on your farm, be careful of the BT that you purchase. Some types sold are transgenic, so look for the OMRI label, or ask questions.

We have a few varieties that we really like. As with so many seed varieties these days, it seems that almost as soon as we decide on a variety, it is dropped from the catalog. Nevertheless, for broccoli, we like ‘Arcadia’ for a main season both spring and fall. It has large heads (10″ in fall), good side-shoot production and a great dark green color. ‘Amazing’ is our main cauliflower variety. Nice white head, good quality. We were told about a variety called ‘Silver Cup’ by a Mississippi State University grower, available from Pinetree Garden Seeds, that was excellent in Mississippi in September! We plan to try it as well. ‘Columbia’ was our best round cabbage and is no longer available, so we’re trying several as replacements this year. However, ‘Capricorn,’ available from Territorial Seed, is a great cone-shaped cabbage – larger and more uniform than ‘Early Jersey Wakefield.’ Cone-shaped cabbage can really set you apart from all the other cabbage growers at a farmers’ market and give you a competitive edge – although you may need to do some customer education about it. In the fall, we also grow some savoy cabbage. Since insect pressure is less, we can get those gorgeous wrapper leaves that really set savoy cabbage apart. The variety we use is ‘Kilosa.’ While writing this, we did some research on transgenic varieties of brassicas – just to see whether they were available. Although we found several instances of them being worked on in research facilities, we didn’t find any commercially available seed. The traits being worked on are insect resistance, as in BT, and herbicide tolerance, so be aware that in the future if you want to avoid transgenic varieties on your farm, you’ll have to read seed descriptions carefully. It’s interesting, however, that the Cauliflower Mosaic Virus is used as a “promoter” for the recombinant genetic process for many other crops.

Growing on is mostly watching the sun and rain do their work. You will need to be vigilant about caterpillars until after a good frost. You may get an aphid infestation, although we never have outdoors. You’ll find that you need to cover the cauliflower as it develops, even in fall, to keep it white. We just break a couple of the leaves over the head to cover it – easier than tying. Broccoli heads will take longer to develop than they do in the spring, and will hold their quality longer in the cooler nights.

Harvest both broccoli and cauliflower when the heads are still tight. Then, cool quickly and keep cool until they’re sold. One more good reason to grow these in fall – Mother Nature often takes care of the refrigeration process. If you have a cooler or root cellar, harvest the last of your cabbages before the temperature drops into the teens, and you can have cabbage for a few more weeks.

Fall brassicas: Give them a try, for yourself and your bottom line.

Paul and Alison Wiediger have 2.5 acres of vegetable production, 8500 square feet of high tunnels and a greenhouse operation on their 84-acre diversified farm in Edmonson County, Kentucky. Their book about growing in high tunnels, Walking to Spring, is available for $15 plus $4 shipping from GFM at www.growingformarket.com or 800-307-8949.