Be sure that your broccoli is in full sunlight. Also, broccoli does best between temperatures of about 40 and 70 degrees F. Warmer temperatures may deter head formation; it might possibly pick up when the weather cools (although broccoli doesn't survive much below 25F). Otherwise, it could be that they got too much nitrogen, which deters flowering and head formation, but encourages leaf growth. As you wait to see if your broccoli perks up in cooler weather, you might also try a fall planting of broccoli. Some varieties that work nicely in Texas are 'Green Comet' and 'Bonanza.' Around Austin, it looks like for a spring planting, it might be best to plant transplants out in the garden in mid-February through early March, so that the plants don't mature during the heat of summer (which can make it bolt or have other troubles).
There is also a phenomenon called "blindness" which can occur with broccoli, in that it does not develop a terminal bud--there is just a nub in the center; this means that the plant will not form a head, just lots of leaves. It is thought that blindness may occur if the plant was exposed to cold temperatures when young (especially during shorter daylengths), the central bud was damaged by insects etc., or possibly the young plants experienced a drought.
Be sure that your broccoli is in full sunlight. Also, broccoli does best between temperatures of about 40 and 70 degrees F. Warmer temperatures may deter head formation; it might possibly pick up when the weather cools (although broccoli doesn't survive much below 25F). Otherwise, it could be that they got too much nitrogen, which deters flowering and head formation, but encourages leaf growth. As you wait to see if your broccoli perks up in cooler weather, you might also try a fall planting of broccoli. Some varieties that work nicely in Texas are 'Green Comet' and 'Bonanza.' Around Austin, it looks like for a spring planting, it might be best to plant transplants out in the garden in mid-February through early March, so that the plants don't mature during the heat of summer (which can make it bolt or have other troubles).
There is also a phenomenon called "blindness" which can occur with broccoli, in that it does not develop a terminal bud--there is just a nub in the center; this means that the plant will not form a head, just lots of leaves. It is thought that blindness may occur if the plant was exposed to cold temperatures when young (especially during shorter daylengths), the central bud was damaged by insects etc., or possibly the young plants experienced a drought.