Prepare soil by working in 3" of rich compost or a thin layer of manure before planting. Spring Season: Plant seeds 2-3 weeks before last spring frost date. Fall Season: Plant seeds in mid- to late-summer in most places.
Plant seeds 1/2" deep. Within a row, space your plants 12-24" apart with 36" between each row.
Thin seedlings to 12 inches apart to give room for the broccoli to grow.
When to Water
Broccoli needs 1 to 1.5 inches of water per week. So water it regularly if rain doesn’t cover it.
Broccoli can withstand hard frost since it's a hardy plant.
Aphids, cabbage looper, cabbage webworm, Cross-Striped Cabbageworm, Diamondback Moth Caterpillars
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 plants can reach a height of 2 1/2 feet.Take that into consideration when planning your garden. Make sure there is enough distance between your tall vegetables and short vegetables. That way both will get enough sun light.
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. Green Comet, an All-American Selection, is a good producer of side shoots.
Broccoli will tolerate frosts of 20°F (6.5°C) and likes daytime temperatures around 50-70F° F (10-20°C) and certainly no higher than 80°F (26°C), or it will bolt to seed. Certain varieties of broccoli are better for warmer areas than others, so check what grows locally or ask at the nearest plant shop for the ideal plants for your garden. Basically, no matter when or how you grow broccoli, there's no getting around the fact that when it matures in the chillier months, it simply tastes the sweetest.
Broccoli plants are heavy feeders and will do well with a dose of fertilizer every couple of weeks. Use a well balanced fertilizer for best results. This will give the plants enough energy to get large enough to support full heads of broccoli.
Broccoli likes steady moisture to grow fast and produce good heads. An organic mulch of compost, finely ground leaves, or finely ground bark will help keep the soil cool and moist and keep down weeds. In cold climates, it’s the opposite, you may need to plant through black plastic in early spring to help warm the soil or leave the ground without mulch so that the sun can warm it.
Broccoli is temperature sensitive. If transplants sit exposed to cold below 40 degrees for a week or two, the chilling injury triggers heads to form way too early. On the other end of the scale, if you plant too late and the weather gets hot, you’ll get the same early blooming, so plant your broccoli on time. The ideal temperature for broccoli is between 65 and 80 degrees.
When you see a flower head beginning to form in the center of the plant, check its growth every day. Ideally, you harvest broccoli while the tiny buds are tightly closed. If the buds begin to swell or show yellow (the flower petals), cut the head from the stem right away, no matter how small it is, because the opening buds have a mealy texture. After cutting the main head, leave the plant to grow bite-sized side shoots in the axils of the leaves. Don’t be disappointed if your broccoli head is smaller that those in the grocery store; they are usually grown in a friendly climate and specialized care.
Broccoli plants like full sun and do well when they get about 8 hours of sunlight.
Garlic, Onions, Peppers, Sunflowers should not be planted next to broccoli.
The following vegetables will do well when planted next to broccoli: Beans, Beets, Celery, Cucumbers, Onions, Potatoes, Sage. Planting certain vegetables next to each other can deter insects and encourage growth.
"Next year, DO NOT plant caulifower, kale, cabbage, Brussels sprouts, turnips, radishes in the same location where you planted broccoli this year. Because they are all members of the Mustard/Brassica family. Instead use that spot to plant other vegetables from a different family such as:
- Carrot (Umbelliferae): celery, carrots, parsley.
- Legume (Leguminosae): peas, beans, lentils.
- Nightshade (Solanaceae) - tomatoes, potatoes, eggplant, peppers.
- Sunflower (Compositae): lettuce, artichokes.
- Cucurbit (Cucurbitaceae): pumpkins, melons, squash, gourds, cucumbers.
- Allium (Amaryllidaceae) - onions, garlic, leeks, shallots and chives.
- Goosefoot (Chenopodiaceae): spinach, Swiss chard, beets.
Growing Broccoli Overview
Broccoli plants are not hard to grow as long as they gets cool weather, full sun, water, and rich soil. They are members of the nightshade family, which also includes caulifower, kale, cabbage, Brussels sprouts, turnips, and radishes. For more planting information, please visit our Farming Tips homepage.