Cole Crops

The cole crops are cool season vegetables derived from the Brassica oleraceae L. plant. They include kale, collards, cabbage, broccoli, cauliflower, kohlrabi, Brussels sprouts, and Chinese kale. Kale and collards are discussed under the greens heading. The other plants were developed for different parts to be eaten. Mississippi produces approximately 400 acres of cabbage and less than 50 acres each of the rest of the cole crops. At one time, Mississippi was a major player in the spring cabbage market.

Frequently Asked Questions

How much boron fertilizer do cole crops require?
The cole crops have a high requirement for boron. Boron is added at two pounds per acre on sandy soils and soils with a history of boron deficiency. Boron deficiency symptoms are expressed as brown streaks through the stem of the crop.

What causes one leaf in a cabbage head to turn brown?
The browning of one leaf in cabbage is called internal tipburn. It is technically a calcium deficiency, but is most often caused by uneven water availability during the growing season. Never allow cabbage to wilt before applying irrigation.

Why are cauliflower leaves tied over the head?
Only pure white cauliflower attracts good prices. The curd of cauliflower will develop a cream color, or even a green color, if it is exposed to long periods of sunlight. Leaves are tied over the head to provide protection from the sun. This is called blanching. Self blanching types have been developed that have upright leaves which protect the head without tying.

Why are high domed broccoli varieties recommended?
Mississippi normally has a high relative humidity and dew every morning. The high dome of the broccoli head helps to shed water and allow the beads to dry out more quickly. Water on the head for several hours can lead to bacterial growth and soft rot.

Which insects cause the holes in cole leaves?
Most of the visible damage caused by insects is due to two larvae. The imported cabbage worm and the diamond backed moth lay eggs on the leaves of cole crops. The larvae which hatch are voracious eaters and cause the holes in the leaves. The larvae prefer young leaves. Be sure to spray the underside of young leaves with an approved insecticide to control them.

Why aren't other cole crops grown in Mississippi?
Cauliflower is the most difficult of the cole crops to grow successfully. It is damaged at 26 degrees and is very intolerant of high temperatures. Mississippi's climate will not allow consistent success with cauliflower. Brussels sprouts require longer periods of cool weather than Mississippi normally experiences. Kohlrabi grows well, especially in the fall, but there is a very small market.

How often can I plant in the same field?
Cole crops should not be planted in the same field for three consecutive years. Rotating to crops will help prevent the build up of disease organisms in the soil. Crops to include in the three year ban are greens, turnips, radishes, rutabaga, and rape. All of the Brassica's share the same diseases.

What type of soil do cole crops need?
Cole crops can be grown on any type of soil as long as water does not stand on it. Soils with poor internal drainage need to be leveled and sloped so water will runoff quickly.

What should plant spacing be for cole crops?
Cabbage and broccoli are often grown with two rows about one foot apart on beds 40 to 42 inches apart. Plants within the row are spaced 18 inches apart. This creates a plant population of approximately 18,000 plants per acre. The rest of the cole crops are grown at about 9,000 to 12,000 plants per acre. There must be air movement in a cole crop field to allow drying of leaves. Always arrange rows parallel to prevailing winds if possible. Higher plant populations often lead to increased disease pressure.