Cauliflower, it’s a wrap

Bob Dluzen
Special to The Detroit News

In many gardens, spring-planted cauliflower is starting to bud and form heads.

Although we call the individual parts of cauliflower heads flower buds, mostly out of convenience, they are actually a different kind of plant tissue.

Meristematic cells are the primordial plant cells that, with the correct genetic instruction, give rise to different plant structures. Some go on to become leaves or stems or any other of the many plant parts.

In the case of cauliflower heads, the meristematic cells get “stuck” and never go on to differentiate. They don’t know that they are supposed to become flower buds. Instead they produce more meristematic cells, those new cells produce even more. That process goes on over and over hundreds of times resulting in the so-called “curds” of the cauliflower head.

As the newly formed heads reach the size of a golf ball or so, they must be blanched.

Blanching is the technique of excluding sunlight from developing cauliflower heads. It is the last step in growing bright white and tasty cauliflower. Exposure to direct sunlight causes the edible part of cauliflower to turn a greenish-yellow, brown or other off color. Not only does the cauliflower look unappetizing, the flavor is ruined, too.  

To blanch cauliflower, fold up the plant leaves up over the developing head so that it is completely covered and no light can reach it. Then secure the leaves with string, soft plant ties, rubber bands or other elastic material.

The tied leaves remain in place until the head reaches full size. That can be as short as a few days during warm weather or up to a few weeks during cool weather.

Tied  leaves for blanching cauliflower heads

Always do your tieing when the plants are completely dry. Trapped moisture will make the curd more susceptible to mold and rot. It’s also a good idea to unwrap the leaves after a rain and let everything dry out before re-tying.

The goal is to produce 5- to 6-inch white cauliflower heads. That is not always possible, however. If you can’t seem to grow cauliflower to the size you’d like, keep in mind cauliflower is a somewhat difficult plant to grow. It demands even soil moisture and reacts negatively to any form of stress such as: insect damage, root damage from deep hoeing, too hot or too cold weather temperatures, weed competition and a number of other stress inducing conditions.

The result of stress is “buttoning,” the production of small heads the size of a quarter or even smaller. No matter how long you keep the button head covered, it will never grow larger.

As the cauliflower head grows under the leaves, you must check it periodically so it is not left on the plant too long, reducing its quality.

Past prime cauliflower curd will begin to separate, looking sort of like grains of rice. Farmers call cauliflower in that condition “ricey.” So harvest at the largest size you can before ricing happens.

Cauliflower varieties with purple, orange or purposely yellow heads never need blanching. Those varieties require sunlight to produce their brightly colored, delicious vegetable.