Seedman Basic Info:
Broccoli does best when set out as transplants rather than planted from seed. It is important to use sturdy transplants and that they become established quickly or the plants may not develop properly.
Plant the broccoli seeds indoors about 6 weeks before you want to plant them outside. They can be planted in the garden about 3 weeks before the frost-free date. Start inside in peat pots or cups, cover 1/4" deep with soil, provide an area that has warmth and bright light.
Broccoli grows well in reasonably fertile, well-drained, moist soils with plenty of added organic matter. A mulch will help keep the ground cool and moist. The pH should be between 6.0 and 7.0 for optimum growth. A pH within this range will discourage clubroot disease and maximize nutrient availability.
Broccoli is a little frost tolerant. Broccoli transplants may be set out in the garden as early as April. For a fall cauliflower crop, set out transplants in early July or about 70 days before your expected first frost.
Broccoli should be spaced 18 inches apart in the row with 24 inches between rows.
Harvest the center green flower bud cluster of broccoli while the buds are still tight and before any yellow petals begin to show. Cut the central stem five to six inches below the head. Many cultivars will continue producing bonus side shoots as long as a few leaves are left on the plant. This can extend the harvest period for a month or more.