Q: How do I stop my broccoli from bolting?

A: Broccoli is a cool weather crop that grows best in soil with temperatures between 65 F. and 75 F. When the soil temperatures get to be 80 F or warmer, the roots of broccoli plants are triggered, causing the plants to bolt. This year we had a short, cool-season growing window before soil temperatures rose quickly and stayed well above the ideal 65 – 75F  range. However, there are few things you can do to prevent broccoli from bolting: all involve keeping the soil cool, because hot soil is actually what causes bolting broccoli. 

• Applying a thick layer of mulch around the broccoli will keep the roots of the plants cool and prevent bolting.
• Watering the broccoli plants frequently in the hot weather will also help keep the soil cool and stop the broccoli from bolting too soon.
• Some gardeners and farmers use floating row cover on cool season crops because the shade helps keep the soil cool.