I have large, healthy cauliflower plants, but there are no heads forming yet. The seedlings were planted in April just after the last frost. I raked a nitrogen based ferilizer into the soil a couple of weeks before planting and then used Miracle Grow generously about a week after they plants were established. The plants have been kept well watered since then, but not overly. They are large with beautiful big leaves. Total plants size is probably at least 18 inches across, but no heads are forming yet. Now we have entered into very hot weather in Oklahoma. I know this is not good for cool weather plants but I thought I would already be harvesting, like I have my lettuce which is almost finished out already. Can I still get heads to form now and what can I do?
Certified GKH Gardening Expert
There are several reasons your cauliflower may not be heading. Too much nitrogen can give you leaves without flowers. It needs phosphorus to produce the nice flowering heads. Your pH might be off too. Cauliflower likes a pH around 6.5. If it's already beginning to get hot in your area, it may be too late this season for your plant to develop heads now, so I'd pull them, as they will only wind up bolting. However, if you want to give it a shot first, try adding some bone meal to the soil and see if this helps. Otherwise, you'll have to wait until the temps get cooler and try again then...using more phosphorus.