Southeastern U.S. Vegetable Crop Handbook - 2022 - 69

PLASTIC MULCH
Early spring cabbage, cauliflower, and broccoli are frequently
grown using plastic mulch, with black mulch used in the spring
and white on black or black mulch painted white used in the fall.
Broccoli. Space raised beds 36-40 inches apart; seed twin rows
per bed 6-12 inches apart within row and 12 inches between row;
for bunch broccoli use the shorter within row spacing which will
also require a more aggressive pest management program; for organic
production single rows per bed can be used and within row
spacing increased to as much 6-24 inch spacing to aide in pest
prevention and maximum fertilizer management.
Brussels Sprouts. Use transplants for best results. Sow seed
4-6 weeks prior to setting seedlings out. Space transplants 18-
24 " between plants into rows 30-36 " apart. Using raised mulch
covered beds will allow tighter plant spacings and enhance earliness.
It is critical to maintain soil moisture and fertility levels
for successful production.
Cabbage. The early cabbage crop is grown from transplants
seeded at the rate of 1 ounce for 3,000 plants. Transplants are
ready for field planting 4 to 6 weeks after seeding. Storage of
pulled, field-grown cabbage transplants should not exceed 9 days
at 32°F or 5 days at 66°F prior to planting in the field. Precision
seeders can be used for direct seeding. However, seed should
be sown 15 to 20 days in advance of the normal transplant date
for the same maturity date. Early varieties require 85 to 90 days
from seeding to harvest, and main-season crops require 110 to
115 days. Set transplants in rows 2 to 3 feet apart and 9 to 15
inches apart in the row for early plantings and 9 to 18 inches
apart for late plantings, depending on variety, fertility, and market
use. With cabbage for slaw or kraut, wider in-row spacings
are used to ensure larger heads.
Chinese Cabbage. Chinese cabbage is a diverse group of
growth types of Brassica rapa. Napa and Michihli resemble romaine
lettuce with densely overlapping broad leaves with flat
mid veins. Napa cabbage is barrel shaped while Michihli is tall
and slender. Choi types have a vase shaped growth with broad
petioles of white or green with green leaves at the top of the
vase. Production inputs are the same as ball head cabbage. Both
types grow more quickly than ball head cabbage with most cultivars
maturing in 50 days from seeding.
Cauliflower. Cauliflower can be more challenging to grow than
other Brassicas in this section. Consider a small test plot to determine
the best methods (planting dates, varieties, etc.) to use in
your area. Start seed in greenhouse or protected frames 4 to 6
weeks before planting. Use 1 ounce of seed for 3,000 plants. Set
transplants in rows 3 to 4 feet apart, and plants are set 18 to 24
inches apart in the row. Make successive plantings in the field at
dates indicated in preceding table.
Collards and Kale. Seed at the rate of 2 pounds per acre and
thin to desired spacing. For precision, air-assist planters use ¹/3
to ½ pound per acre for twin rows on 3 foot centers, or use half
of this rate for single rows on 3 foot centers. When using trans2022
Vegetable Crop Handbook for Southeastern United States
plants, set plants in rows 16 to 24 inches apart and 6 to 18 inches
apart within the row.
Kohlrabi. Transplants may be used for a spring crop. Seed 6
weeks before expected transplant date. Use precision seeder for
hybrid varieties. Space rows 18 to 24 inches apart and 6 to 8 between
plants.
Bolting. Bolting in cabbage, collards and kale, and buttoning in
cauliflower, can occur if the early-planted crop is subjected to 10
or more continuous days of temperatures between 35° to 50°F.
However, sensitivity to bolting depends upon the variety. Note:
A Low level of calcium in plant tissue can also induce bolting.
SPECIAL NOTES FOR PEST MANAGMENT
Note: The use of a spreader-sticker is recommended for cole
crops in any case; the heavy wax coating on the leaves reduces
deposition of spray materials. These adjuvants allow the spray
to spread out and stick to the leaves. Multiple nozzles per row or
bed will provide the under leaf coverage and high coverage rates
necessary to manage caterpillar pests of cole crops.
INSECT MANAGEMENT
Aphids: The cabbage aphid can be a serious problem on these
crops and should be treated immediately if noticed. Other aphid
species are found on these crops and should be treated if the crop
is near harvest or their level of infestation is increasing. Often
parasitic wasps take out these species if broad-spectrum insecticides
use is avoided.
Cabbage Root Maggot: Root maggots and other similar insects
such as the seed corn maggot can be a problem in heavier soils
in the Southeast especially during cool, damp times of the year.
Avoid planting into soils with freshly plowed down crop residue
or high levels of organic matter.
Caterpillars: A number of moth and butterfly larvae feed on cole
crops. The major ones are the cabbage looper (CL), the imported
cabbageworm (ICW), and the diamondback moth (DBM) referred
to as the cabbageworm complex. Other caterpillars found
on cole crops are the cross-striped cabbageworm, corn earworm,
armyworms, and webworms. Webworms often damage the bud
of the young plants and should be treated immediately; very
young larvae are much more easily managed than older ones.
Scouting and using a threshold for spray applications is a
cost effective method of managing these pests. Broad-spectrum
insecticides that reduce the natural enemies in the field should
be avoided if at all possible. If the cabbageworm complex is the
major group of pests, a threshold of 1 cabbage looper equivalent
(CLE) per 10 plants can be used. A cabbage looper equivalent
relates the feeding amounts of the three caterpillars. One
cabbage looper is equivalent to 1.5 imported cabbageworms or
5 diamondback moth larvae. (Example: 10 DBM larvae per 10
plants would be like 2 CLEs per 10 plants; this level would require
treatment.) In other areas of the South where armyworms
are common pests of cole crops, a threshold of 1 caterpillar (regardless
of the kind) per 3 plants has been effectively used as a
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Southeastern U.S. Vegetable Crop Handbook - 2022

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