Non-Pest Cole Crop Problems
Many gardening problems can be solved or prevented with nothing more than old-fashioned common sense. Here are some tips for growing the best possible cole crops.
Weather's the Culprit
Sometimes weather conditions cause cole crops to fail to produce quality heads. If seedlings suffer from stress in their first month or so of growth (temperatures below 55° F, lack of nutrients or water), they may form small heads or no heads at all. This is especially true with cauliflower. Even though you can't alter the weather, raising your own seedlings and staggering your plantings can give you a hedge against these problems.
Many problems can be avoided simply by timely harvesting.
The most common cabbage problem seems to be cracking or splitting heads. This is usually caused by too much fertilizer or water, which causes the new inner leaves of the heads to grow faster than the older outside leaves.
To avoid cracking, don't overfertilize cabbages, and try to maintain an even moisture supply. If a head starts to split, you can stop it by "shutting off the faucet". Simply grasp the head and rotate it about one half turn. This "root prunes" the plant, cutting some roots so the head draws less food and water. Then the outer leaves have a chance to catch up with the inner leaves, and the cracking ceases to be a problem. If it keeps splitting, however, just give the plant another half turn.
Sometimes an overmature head will crack, so try to harvest cabbages while they're still in their prime -- firm and smallish.
Most gardeners run into needless trouble with cauliflower when it's time to blanch the heads. The reason you blanch cauliflower when it's growing is to make the head white and tender. It sounds as though it might be hard to do, but you only need to cover the young head before the sunlight hits it.
As soon as the head is 3 to 4 inches across, shield it from light by loosely tying or pinning the large outer leaves over the cauliflower head. It's even easier if you simply bend the leaves over on all sides of the head and tuck them under it on the opposite side. Light stays out, but air circulation seems better than when the leaves are secuured at the top.
Check the heads daily after blanching, and start harvesting as soon as the first head is snowy white. You may have to harvest one or two heads a day because cauliflower loses its fine texture and taste as soon as the tight buds start to loosen. A head that's past its best harvest time is "ricey" -- the buds separate and become somewhat granular. There are self-blanching cauliflower varieties that also work well.
Brussels Sprout Problems
You can affect the growth of the Brussels sprout plants two ways: by pruning the leaves along the stem and by pinching off the growing tip, called the terminal bud, on top.
For the best results with the pruning method, snap off all the leaves on the bottom 6 inches of stalk when the plant is well established and the buds have just started to develop. The leaves break most easily in the morning when they're crisp from the dew. This encourages more leaves to form higher up on the stalk and makes the plant grow taller. The sprouts are formed just above each leaf, so more leaves mean more sprouts.
Pinching the growing tip directs the plant's energy into making more leaves, less stalk and earlier, larger sprouts. It also causes the sprouts to mature earlier and at the same time, which is more helpful to commercial growers and northern gardeners than to gardeners with a longer growing season. To remove the top, wait until sprouts have formed on 10 or 12 inches of the stem.
Although it's not necessary to prune or pinch back the top of Brussels sprouts, breaking off the leaves does make harvesting easier. You can begin harvesting when the first sprouts are marble-sized.
Broccoli, Chinese cabbage and kohlrabi don't need any special attention other than protection from diseases and insects that often bother the cabbage family.