Midwest Vegetable Guide - 2022 - 103

Cole Crops and Brassica Leafy Greens - Horticulture
Cauliflower: Rows 3 feet apart. Plants 15 to 18 inches apart
in row, or 12 to 15 inches apart in row for self-blanching
types.
Collards: Rows 3 to 3.5 feet apart. Plants 18 to 24 inches
apart in row. Seed 1 to 2 pounds per acre.
Kale: Rows 2 to 3 feet apart. Plants 8 to 16 inches apart in
row. Seed 2 to 4 pounds per acre. Use denser plantings if
harvesting small leaves for salad or braising mixes.
Kohlrabi: Rows 2 to 3 feet apart. Plants 4 to 12 inches apart
in row. Plant more densely to harvest small plants early and
allow later harvested plants to grow larger.
Mustard: Rows 1 to 1-1/2 feet apart. Plants 10 to 12 inches
apart in row. Seed 3 to 5 pounds per acre. Use denser
plantings if harvesting small leaves for salad or braising
mixes.
Turnip greens: Rows 6 to 12 inches apart. Plants 1 to 4
inches apart in row.
Fertilizing
pH: Maintain a soil pH of 6.0 to 6.5.
Broccoli, Brussels sprouts, cabbage, cauliflower, and
kohlrabi:
Before planting, apply 50 to 60 pounds N per acre, 25 to 200
pounds P2O5 per acre, and 0 to 250 pounds K2O per acre
based on soil test results and recommendations from your
state. Cole crops, particularly cauliflower, are responsive to B
on low organic matter soils, sandy soils, or where the pH is
greater than 7.0. If B is needed, apply 1 to 2 pounds B per
acre broadcast. Soil test and/or perform plant analysis on the
previous crop to be sure B is needed. High soil B can be
detrimental to rotational crops such as sweet corn, peas, or
beans. At transplanting, a starter solution at a rate of 1 cup (8
ounces) per plant is recommended. If the transplant flat
receives a heavy fertilizer feeding just prior to setting, the
starter solution can be eliminated.
Sidedress with 40 pounds N per acre three to four weeks after
transplanting and again three weeks later. On organic soils
only one sidedressing is needed. Avoid excessive N
fertilization with broccoli as it can cause too rapid growth and
a hollow flower stalk. Reduce the amount of fertilizer N
applied by the value of N credits from green manures, legume
crops grown in the previous year, compost and animal
manures, and soils with more than 3 percent organic matter.
The total amount of N from fertilizer (including starter) and
other credits should be 140 pounds per acre.
Collards, kale, and mustard:
Before planting, apply 50 to 60 pounds N per acre, 0 to 150
pounds per acre P2O5, and 0 to 200 pounds K2O per acre
based on soil test results and recommendations from your
state.
Sidedress with 30 pounds N per acre two to three weeks after
transplanting on soils with more than 3 percent organic
matter and following a legume crop. For greens on soils with
less than 3 percent organic matter and following legume
crops, apply 45 pounds N per acre. For greens following
corn, small grains, or a vegetable crop, apply 60 pounds N
per acre. The total amount of N from fertilizer (including
starter) and other credits should be 120 pounds per acre.
Harvesting
Broccoli: Harvesting is done by hand while the head is still
compact and before the flowers open. The central heads
should be dark blue or green and 4 to 6 inches across when
mature. If harvesting too late or when the heads are over
mature, woodiness in the stems will develop. Depending on
your marketing requirements, the main head is cut with 8 to
10 inches of stem. Sometimes a second harvest of side shoots
can be obtained. Broccoli for processing should be cut with
less attached stem (6 to 7 inches) and with few or no leaves.
Fresh market broccoli should be cut longer, with little
trimming. Broccoli quality is based on the degree of
compactness, leafiness, head trimness, damage, and freedom
from insects and extraneous debris. During the critical period
of head formation, prolonged periods of heat (over 85° F)
result in poor head quality. Broccoli varieties range in
maturity from 55 to 75 days.
Brussels sprouts: Harvest when the buds are about 1 inch in
diameter, firm, tight and of good color. Sprouts can be
harvested as they reach marketable size, or during one single
harvest at the end of the season. In a once-over harvest
sprouts can be harvested individually, or entire stalks can be
cut. Harvesting the entire stalk saves on labor in the field and
extends the shelf life of the buds. The flavor is best after the
first frosts of the season. Brussels sprouts are generally long
season crops ranging from 80 to 110 days to maturity and
harvested in the fall.
Cabbage for fresh market and processing: Cut cabbage
when the head has reached a marketable size of 6 to 12 inches
in diameter. Peel off the first few wrapper leaves for fresh
market sale. Cabbages for processing into kraut are harvested
similarly. Cabbage for the bagged salad market are
sometimes field-cored. Cabbage varieties range in maturity
from 60 to 120 days.
Cauliflower: When ready to harvest, the heads should be
compact and clean white. Typical harvest size for wholesale
markets is a diameter of approximately 6 inches, but heads
can reach 12 inches in diameter and sell well. Delaying
harvest usually will not result in obtaining larger heads. If
larger heads are desired consider cultivar selection and wider
plant spacing. Cauliflower should be hand-harvested and cut
Midwest Veg Guide 2022
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Midwest Vegetable Guide - 2022

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