Apply fertilizer to developing seedlings beginning when the first true leaves appear. Fertilize three weeks after transplanting. Use starter fertilizer for transplants and side-dress with nitrogen fertilizer when the plants are half grown 6.
Water regularly – broccoli requires large amounts of water. Both dry soil and waterlogged soil reduces yields. Some varieties of broccoli are heat tolerant, but all need consistent moisture. Do not get developing heads wet when watering 4.
Mulch well to control weeds and to regulate the soil temperature.
The roots are very shallow, do not cultivate around your planting – suffocated weeds with mulch instead 4.
Monitor for insect and disease problems.
Many broccoli varieties are prone to bolting in hot weather.
Handle transplants carefully, control cutworms and avoid low temperatures to avoid damage to the terminal growing tip. Most Broccoli varieties grow best when temperatures are not too hot or too cold. Purple sprouting broccoli is a hardy variety which is planted in the spring or summer for harvest the following spring.
Ideal brassica crop rotation is to only grow them once in every 3 years in the same plot. Good preceding crops are onions and potatoes, or various (non-cruciferous) green manures, such as clover or ryegrass 5.
Sow indoors 2-3 weeks before your last spring frost, for spring planting. For autumn planting, sow 85-100 days before your first expected frost 4.
Try to aim for a seed spacing of at least 5.85 inches (15.0 cm) and sow at a depth of around 0.51 inches (1.3 cm). Soil temperature should be kept higher than 10°C / 50°F to ensure good germination.By our calculations*, you should look at sowing Broccoli about 45 days before your last frost date .
Can be station-sown direct, but for best results should be raised in seed bed and transplanted when big enough to handle. Transplant broccoli when seedlings have second set of leaves.
Ensure that temperatures are mild (minimum night temperatures should be around 7°C / 45°F) and all chance of frost has passed before planting out, as Broccoli is a half hardy plant.By our calculations*, you should look at planting out Broccoli about 21 days before your last frost date.
Harvest broccoli when the flower shoots are well developed, but before the flowers themselves have opened.
Broccoli will cross-pollinate with all other Brassica oleracea, so isolate when going to seed. Do not harvest heads on plants you intend to save for seed. 2 Some early broccoli will flower in the first year. Remove whole plant and hang to dry. 3
Seed viability is three to five years.
These estimates for how long Broccoli takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.
Average 6 days | Min 2 days | Max 18 days (712)
Average 35 days | Min 1 days | Max 88 days (273)
Average 100 days | Min 4 days | Max 229 days (524)
Our when to plant Broccoli estimates are relative to your last frost date.
Calabrese, Purple sprouting broccoli, White sprouting broccoli
Brassica oleracea, Brassica oleracea var. italica
Misspellings: Brocoli, Brocolli, Broccolli, Brassica oleracea var. italica, Broccoli, Brassica olderacea italica, Brokoli
3 “The New Seed-starters Handbook; Published 1988”