Question: I planted several broccoli plants a month ago. They were growing beautifully, but now the heads of broccoli are covered with yellow flowers. Why, and what do I do?

Answer: Sounds as though your plants bolted. Broccoli grows best in cool weather. When it gets too hot the flower buds that actually make up a head of broccoli quickly open up into the yellow flowers you see. There's no way to save your plants once they've bolted. Try planting again in late summer for a late winter harvest.