Midwest Vegetable Guide - 2022 - 102

Cole Crops and Brassica Leafy Greens - Horticulture
Cole Crops and Brassica
Leafy Greens - Horticulture
Major update by Ben Phillips, Liz Maynard - Oct 2020
Reviewed by Liz Maynard - Aug 2021
Crop Description
The term " cole crops " refers to leafy brassicas, with waxy
leaves, of the species Brassica oleracea. Cabbage,
cauliflower, broccoli, Brussels sprouts, kale, collards, and
kohlrabi are hardy crops and well adapted to cool weather.
Mustard and turnip greens, although not cole crops, are also
frost-hardy and adapted to cool weather. Careful selection of
the planting date and cultivars is crucial to a good harvest in
the Midwest. Many cole crop varieties need 80 days or fewer
to mature and can be sequentially planted in the spring
through mid-summer for sequential harvests starting in the
summer through late fall. Some Brussels sprouts, cabbage,
and cauliflower varieties need over 100 days mature, and
require a full season. Plants maturing under cool weather
conditions are the highest in quality.
Broccoli: There are heading-types of broccoli that form a
distinct domed head, and sprouting " broccolini " types that
produce smaller sprigs of flower buds for multiple harvests.
There are purple varieties as well. Broccoli is relatively fastmaturing,
and varieties can be planted in spring for summer
harvest and summer for fall harvest.
Brussels sprouts: Brussels sprouts require the entire season
from spring to fall to produce small cabbage-like buds in a
spiral around the stalk of the plant at the base of each leaf.
Cabbage: Among the brassica crops, cabbage is the most
widely grown. Small-headed varieties of cabbage (3 to 4 lbs.)
are the most desired varieties for fresh market sales. Some
varieties can be planted in spring for summer harvest, and in
summer for fall harvest. Others require the entire season from
spring to fall to mature.
Cauliflower: Cauliflower is relatively more difficult to grow.
The most common problems associated with cauliflower
production are failure to head properly and poor curd quality.
Cauliflower buttoning is the premature formation of curd.
When the curd is formed very early in the plant's life, the
leaves of the plant are not large enough to sustain its
development to a marketable size. Cold temperatures during
seedling production or at transplanting encourage buttoning.
In order to produce a white curd, leaves are tied over the
developing head when it is about the size of a baseball to
block out sunlight and blanch it. Self-blanching varieties
produce leaves that naturally shade the curd, but they need to
be planted closer together to effectively self-blanch, resulting
in smaller head sizes. Orange, green, and purple colored
varieties, and greenish Romanesco-types do not require
102
blanching. Some varieties can be planted in spring for
summer harvest, and in summer for fall harvest. Others
require the entire season from spring to fall to mature.
Collards: Varieties differ in leaf color and texture, tendency
to head, and tendency to bolt. Some varieties may be tender
enough to harvest at young stage for salad mixes.
Kale: Types and varieties differ in leaf color, texture, and
shape. Scotch or Curly kale varieties have frilly leaf margins;
cultivar examples include Winterbor, Darkibor, and Redbor
(purple-red leaves). Lacinato, also called Tuscan or dinosaur
kale, has long narrow leaves with smooth leaf margins and a
puckered leaf surface; examples include Black Magic and
Toscano. Siberian kale is a different species: Brassica napus
var. pabularia. Siberian kale has wavy lobed leaf margins
and is somewhat more tender in terms of eating quality than
the curly kales; young leaves do well in salad mixes.
Varieties White Russian and Dwarf Siberian are examples.
The variety Red Russian has sharply lobed leaves with purple
veins; leaves are commonly harvested at a small size for salad
mixes. Kale flavor is best when grown in cool weather and
harvested after a light frost.
Mustard: Mustards come in a wide variety of leaf shapes,
colors, and textures. Leaves may be harvested for salad or
braising mixes when young, or allowed to grow to full size
and sold in bunches.
Kohlrabi: The edible stem of kohlrabi looks like a turnip
growing on top of the ground with sprouting leaves over the
surface. Green and purple varieties are available. It can be
ready to harvest sooner than most cole crops and therefore
can fit well as a crop for farmers markets early in the season.
Planting and Spacing
Brassicas can be planted from seed, but, aside from baby
greens, are more commonly established as transplants. Raised
beds (6 inches high, 40 inches wide, with 2 rows 11 inches
apart on beds) may be desirable under certain conditions.
Broccoli: Rows 3 feet apart. Plants 12 to 18 inches apart in
row.
Brussels sprouts: Rows 3 feet apart. Plants 18 to 24 inches
apart in row. Removing the growing point at the top of the
plant when the oldest sprouts are about half their full size can
speed development of the remaining buds.
Cabbage for Market: Rows 2 to 3 feet apart. Plants 12 to 15
inches apart in row.
Cabbage for Kraut: Rows 3 feet apart. Plants 18 inches
apart in row.
Midwest Veg Guide 2022
Midwest Vegetable Guide - 2022

Table of Contents for the Digital Edition of Midwest Vegetable Guide - 2022
