|My early hybrid white cauliflower grows normally and produces good sized heads, but the florets develop a purplish tinge, slight at first and becoming more pronounced the longer the head stays on the plant, until the whole head has purple color at the tips of the florets. It is not very appetizing but seems to taste OK. What causes this and is it OK to eat?|
|As a cauliflower heads appear they need to be kept shaded--if the developing heads are exposed to sunlight they develop this purple tinge. This process of keeping the heads shaded is called "blanching".
Some cauliflowers are "self-blanching" in that they grow their own "shading" leaves, but even these sometimes need blanching if their protective leaves wilt.
There are a few things you can do. One is to draw up a few large leaves over the head and fasten them loosely together (you can use a clothespin). You can also break off one of the larger leaves from the bottom of the plant and lay it on top of the head in order to provide shade.
Often high humidity can cause this coloration as well, so be sure that air can circulate freely under the clipped- together leaves.
I have never seen anything to indicate that these discolored heads are a problem as far as eating. Certainly there are purple and yellow-green heads that are cultivated that way!