Lettuce, cabbage, cauli and broccoli have big leaves but fail to form into hearts. What should we be doing?

ah could be too much nitrogen in the soil, apply a super phosphate and some potash next time. these help plants flower. adding too much nitrogen is a common problem for brassicas and all they do is produce lots of leaves but no fruit/ heart
Lettuce, cabbage, cauli and broccoli have big leaves but fail to form into hearts. What should we be doing?
If they form into hearts they will capture less sunlight. Leave Mother Nature alone.
Reply:you are using some type of pesticide that is keeping the bees away



cant get fruit unless you get polination