Vegetable Gardening (64 page)

Planting fall cole crops

For gardeners in all but the coldest areas, a fall-maturing crop of broccoli, Brussels sprouts, cabbage, and cauliflower may be easier to manage than a similar summer-maturing crop. Fall weather provides the perfect temperatures to mature cole crops to their sweetest flavor.

For fall cole crops, start seedlings indoors about 3 months before your first frost and then transplant the seedlings to the garden 1 month later. For example, if your first frost is November 1, you should start seeds indoors on August 1 and then transplant them in your garden on September 1. (Starting the seedlings indoors and letting them grow until they're 3 to 4 weeks old helps them withstand the shock of being planted in the garden in summer.) To protect the young seedlings from the harsh summer sun, mulch them with hay or straw immediately after planting, and shade them — especially in the afternoon — with a shade cloth or
floating row cover
(a plastic or fabric material that lets light through but insulates the plants). (Refer to Chapter 21 for information on row covers.)

In very mild-winter areas such as the U.S. West coast and the Gulf coast, try growing
overwintering
varieties of broccoli (varieties that can withstand cold temperatures better than other varieties and need a longer season to mature) such as ‘Purple Sprouting', which I discuss earlier in the chapter. Planted in fall, such varieties slowly grow all winter and mature in spring.

Nurturing cole crops

Cole crops like full sun and well-drained soil that's built into raised beds. Most importantly, though, cole crops really like fertile soil. A week or so before planting your seedlings, work a 3- to 4-inch layer of composted manure into the bed. About 1 month after you transplant your cole crop seedlings, apply about 3 to 4 pounds of an organic fertilizer, such as 5-5-5, to every 100 square feet of garden. (Chapter 15 has more on fertilizing.) Keep the soil moist, and a week or so after transplanting, apply an organic mulch such as hay or straw. These types of mulches keep weeds at bay and keep the soil cool and moist — just how cole crops like it.

I stress the importance of cool weather for cole crops throughout this chapter, but mild temperatures can be too cool for some cole crops. Even though mature cole crop plants can withstand temperatures into the 20s, young plants may not be so hardy. If broccoli plants are exposed to several days of 40-degree temperatures when they're still young, they can form flower heads prematurely when the weather warms (which is called
buttoning
). Cauliflower does the same thing when exposed to cold temperatures or other stresses, such as crowding, when young. In either case, you're left with a small plant and head. To avoid this premature flowering, plant in summer for a fall crop or cover young spring-planted crops with a row cover to keep them warm.

With older cauliflower varieties, such as ‘Snow Crown', you have to wrap the leaves over the head and tie them with twine, as shown in Figure 9-2. However, many newer varieties, such as ‘Fremont', are
self-blanching
(the leaves naturally grow to cover the head and avoid light) as well as disease resistant. However, even newer varieties benefit from careful inspection to ensure that the leaves are tightly covering the heads once they form.

Keep the plants well watered, weeded, and mulched so they grow steadily through the season. Side-dress cole crops with an organic fertilizer such as 5-5-5 about 1 month after transplanting in the garden. (For more on side-dressing, flip to Chapter 15.) Nurture your plants, and they'll reward you with a bountiful harvest.

Putting a stop to pesky pest problems

In general, cole crops have only a few problems that home gardeners need to watch out for. Many modern hybrid varieties have added disease resistance, so choose these varieties if diseases are a problem in your garden. I discuss general vegetable diseases and pests, such as cutworms, aphids, nematodes, flea beetles, and mildews, in Chapter 17, but the following list warns you about some specific cole crop pests:

Black rot:
This bacterial disease is a problem particularly with cabbage and cauliflower. It causes the plant or head to rot before maturing. The telltale signs are a foul smell, a yellowing of the lower leaves, blackening of the leaf veins, and triangular yellow areas on the leaf edges. You can control this problem by
rotating crops
(planting other unrelated crops such as tomatoes, beans, or lettuce in that area for 3 years) and removing all old cole crop plant debris.

Cabbage maggot:
If plants are stunted, pull one up and look at the roots. If you see small, white larvae (maggots) feeding there, you probably have
cabbage maggots.
The adult fly lays eggs on the stems at the soil line and then when the eggs hatch, the larvae tunnel into the soil and start feeding on the roots. The maggots are especially dangerous to young seedlings. To control the cabbage maggot, place a floating row cover over the young seedlings. After the weather warms, remove the row cover.

Club root:
If your plants are stunted, pull one up and check the roots. If the roots are gnarled and disfigured, a fungus called
club root
may be to blame. To prevent this disease, rotate crops and raise the soil pH to 7.2 by adding lime (see Chapter 14 for more on acceptable pH ranges for vegetables).

Imported cabbageworm and cabbage looper:
These two insects are the number-one problem with cole crops. The adult of the cabbageworm is a seemingly harmless white butterfly that lays single white eggs on the undersides of leaves. The eggs hatch, and then green caterpillars crawl out and begin to feed on the leaves. The adult of the cabbage looper is a gray-brown moth. These pests can quickly destroy your crop. As soon as you see signs of feeding — including the caterpillars or their dark green droppings — spray the crop with a biological control called
Bacillus thuringiensis
(Bt). Bt is an effective bacteria that attacks only the larvae of caterpillar family insects and is safe to other insects, animals, and humans.