Here are my tips for growing great broccoli:

Site, soil type:

Broccoli needs very fertile soil.

It likes moisture and coolness.

Plant after a legume for extra nitrogen.

Consider planting in light shade to avoid maturing in the high heat of summer, but it will slow down growth.

Planting requirements:

Start indoors six weeks before planting outside.   Plant outside after temperatures won’t go below 45 degrees.  Otherwise the stress will cause heads to mature at a small size.

Set transplants 1” deeper in the ground than they were in the container.

Nutrition/Fertilizer needs:

Broccoli is a high feeder.

Add ¼ to ½ cup of complete organic fertilizer per plant.

Water needs:

It’s thirsty.   Keep soil wet constantly.

Other tips:

Plant a variety that produces many side shoots for an extended harvest period.

Aromatic herbs planted nearby will deter cabbage worms.

A lightweight row cover will exclude cabbage worms.

Use Bt for the elimination of cabbage worms.

Create a Bt bait by mixing wheat bran into Bt.  Add 1 tablespoon of molasses.  Spread around the base of plants.

Eliot Coleman says that cabbage worms aren’t a pest when plants are grown well.