Bitter Flavored Broccoli
I have tried growing broccoli for several years. The plants look fine but the flavor is bitter.
Broccoli, just like cabbage, cauliflower and Brussels sprouts is a cool weather plant. It grows, produces, and tastes best in cooler weather (65 to 75 degrees). Plant transplants outdoors in early spring so the harvest occurs before hot weather arrives. Wait until the prolonged cold period have passed or provide extra protection with a cold frame, wall-o-water or floating row cover like ReeMay or Harvest Guard. Broccoli subjected to 10 or more days of below 50 degrees will set flower resulting in poor establishment and a very small harvest. Or try a fall crop. Place transplants in the garden in the summer. These will be ready to pick in fall when the temperatures start to cool. Don't worry about fall frost. A light frost on established plants will improve the flavor.