Most people think of gardening as a spring and summer
activity. As I walked through the Discovery Garden
in Carbide Park last week on a cool and sunny
Thursday morning, I was inspired by the abundance
of winter vegetables being grown: broccoli, cauliflower,
kale, beets, Irish potatoes, cabbages, onions, and
the list goes on.
Many of the vegetables that Master Gardeners
planted in late summer and early fall are now ready
to harvest (or will be soon). It is important to harvest
vegetables at the proper stage for best results, so
here are a few guidelines for some common coolseason
crops.
*Root crops are usually harvested when the top of
the root becomes readily visible at ground-level, but
it is easy enough to brush aside the soil at the base
of the leaves to check on the size of the root. Harvest
radishes and carrots when the root is about an inch
across.
*Carrots can be left in the ground once they are
mature and harvested as needed, and the tops can
be used as a parsley substitute. Turnips should be
harvested when they are 2 to 3 inches in diameter,
and rutabagas (a close relative) when they are 4 or 5
inches in diameter. Beets are best harvested at 2 to
3 inches and parsnips at 1 1/2 to
2 inches.
Incidentally, to get good production,
these plants must be
spaced properly in the garden.
When the seeds that you plant
come up, it is very important to
thin the seedlings at least as far
apart as the width of the mature
root in order to get good production.
Leaving the seedlings too
crowded is a common reason for
root crops to produce small or
misshapen roots.
*Broccoli heads are not harvested
based on the size of the
head, but when the largest individual
flower buds are about the
size of a kitchen match head. Cut
the primary crown (where the individual
heads come together)
when it’s about 4 inches across.
Do not allow the heads to remain
on the plant so long that some of
the buds start to open and produce
yellow flowers. Remember
that smaller side heads will develop
after the main head has been
harvested, so leave the plant in
place for additional harvest.
*Harvesting cauliflower also
depends more on the appearance
of the head rather than
its size. The curds of the head
should be relatively smooth, very
much like the cauliflower that
you buy in the supermarket. If allowed
to stay on the plant too long, the head will begin
to separate and lose quality. If you did not blanch
your cauliflower by covering the head with the plant’s
leaves, it may have a purple, green or yellow tint to it.
This does not greatly affect the quality of the head.
*Leafy crops such as mustard, spinach, Swiss
chard, leaf lettuce, collards and turnips should be
harvested frequently by breaking off the lowest, largest
leaves (this is called cropping). Harvest the entire
head of semi-heading varieties of lettuce such
as Bibb, buttercrunch and romaine when the head is
fully developed.
*Cabbage is ready to harvest when the head is
solid and hard. Cabbage is one of the few crops that
may be left in the garden after they are ready to harvest,
although the heads may split. If you are going to
leave fully formed heads in the garden, rotate the entire
plant one-half turn to prevent splitting (this slows
water uptake by breaking some of the roots).
*Bunching onions and green shallots can be harvested
anytime during the winter when the tops are
large enough. Dig up the entire clump and separate
off one half of the bunch, and then replant the rest to
continue to grow and divide for future harvesting.
Cold protection for winter vegetables
Although winter vegetables are generally hardy,
new plantings may need to be protected from hard
freezing, as will certain vegetables near or at harvest
stage. If temperatures below 30 degrees are predicted,
young seedlings should receive special attention
by completely covering them with a 4-to-6-inch layer
of loose mulch like leaves or pine straw. The mulch
may remain over the plants for a few days but remove
it as soon as the freezing episode is over. Other protections
include plastic coverings supported to keep
them off plants. Fabric sheets or floating row coverings
may also be used.
The following lists will give you a quick guide to the
ability of some vegetables to endure freezes.
– Broccoli, Cauliflower, Lettuce and Peas: protect or
harvest if temperatures are predicted to go below 30
degrees.
– Swiss Chard, Chinese Cabbage, Kohlrabi, Mustard,
Spinach, Radish and Turnip: tolerate temperatures
down to the mid-20s with little or no damage.
– Beet, Brussels Sprout, Carrot, Celery, Collard,
Garlic, Onion, Parsley, Leek and Shallot: will survive
temperatures in the low 20s and even the teens, especially
if given some protection.
Most salad greens are a great “cut and come again”
vegetable. Mustard is one of the leafy crops along with
spinach, Swiss chard, leaf lettuce, and collards that
should be harvested frequently by breaking off the lowest,
largest leaves.
