Growing Broccoli

Planting, Growing, and Harvesting Broccoli

Broccoli Florets

Broccoli is a sun-loving, cool-season crop that is best grown in the spring or fall. It’s also incredibly healthy and dubbed the ‘crown jewel of nutrition.’ Here’s how to plant, grow, and harvest broccoli in the garden!

Broccoli is worth growing for its goodness alone. The annual vegetable is rich in vitamins and minerals, and is a good source of Vitamin A, potassium, folic acid, iron, and fiber. 

Once you harvest the main head of a broccoli plant, it will often keep producing smaller side shoots that can be enjoyed for months to come.

Just note that excessive summer heat can cause bolting, so broccoli is best grown in the cooler spring and fall seasons.

Planting

  • Broccoli requires full sun and moist, fertile soil that’s slightly acidic.
  • Before you plant, in early spring, work in 2 to 4 inches of rich compost or a thin layer of manure before planting. (Learn more about soil amendments and preparing soil for planting.)
  • Direct seed broccoli seed in the ground once the soil is at least 40°F. Generally, this is 2 to 3 weeks before the last spring frost date. See our free online Planting Calendar for local seed-starting dates. Plant seeds ½ of an inch deep and 3 inches apart.
  • Or, set out transplants (with 4 or 5 leaves) about 2 to 3 weeks before the last spring frost date, 12 to 20 inches apart, in holes slightly deeper than their container depth. 
  • Space rows 36 inches apart. (close spacing yields smaller main heads but a higher yield of secondary heads.)
  • Water well.
  • Plants thrive outdoors in 65°F to 70°F conditions.
  • For fall plantings (especially good in warm climates), direct-sow 85 to 100 days before the first fall frost, when soil and ambient temperatures are high. Or, start seeds in late May.Water well.
  • Growing Broccoli

Care

  • Fertilize broccoli three weeks after transplanting seedlings into the garden. Use a low-nitrogen fertilizer.
  • Thin when plants reach 2 to 3 inches tall.
  • Provide consistent soil moisture with regular watering, especially in drought conditions. Water at least 1 to 1 ½ inches per week.
  • Do not get developing broccoli heads wet when watering, as it can encourage rot.
  • Roots are very shallow, so try not to disturb the plants. Suffocate weeds with mulch.
  • Mulch will also help to keep soil temperatures down.
  • Use row covers to minimize pests.
  • To promote the growth of a second head after the first has been harvested, maintain an active feeding and watering schedule.
  • If bottom, then top, leaves turn yellow, add blood meal.
  • Learn more about taking care of your broccoli plant.

Pests/Diseases

  • Aphids: Curling leaves may mean that the plant’s sap is being sucked by insects. Apply soapy water to all sides of leaves whenever you see aphids.
  • Cabbage loopers: Small holes on the leaves between the veins mean small green caterpillars are present. Look at the undersides of the leaves. Hand pick if the problem is small or control with Bacillus thuringiensis, a natural, bacterial pesticide. Use a floating row cover just after planting through harvest to prevent caterpillars.
  • Cabbage root maggots
  • Cabbageworms and other worm pests: Treat same as loopers.
  • Clubroot: Quickly wilting plants may be due to this fungus in the soil. The entire plant, including all roots and root tendrils, must be gently dug up and removed. If the roots are gnarled and misshapen, then clubroot is the problem. Act quickly to remove the plants so that the fungus doesn’t continue to live in the soil. Do not compost the plants. Raise the pH of your soil to above 7.2. You may need to sterilize your soil, too.
  • Downy Mildew: Yellow patches on leaves are usually caused by moist weather. Keep leaves as dry as possible with good air circulation. Buy resistant varieties.
  • White rust
  • Whiteflies
  • Nitrogen deficiency: If the bottom leaves turn yellow and the problem continues toward the top of the plant, the plants need a high nitrogen (but low phosphorus) fertilizer or blood meal. Blood meal is a quick nitrogen fix for yellowing leaves.

Broccoli close-up

Harvest/Storage

How to Harvest Broccoli

  • Harvest broccoli in the morning before it heats up when the buds of the head are firm and tight, just before the heads flower.
  • If you do see yellow petals, harvest immediately, as the quality will decrease rapidly.
  • Cut heads from the plant, taking at least 6 inches of stem. Make a slanted cut on the stalk to allow water to slide away. (Water can pool and rot the center of a flat-cut stalk, runing the secondary heads.)
  • Most varieties have side-shoots that will continue to develop after the main head is harvested. You can harvest from one plant for many weeks, in some cases, from spring to fall, if your summer isn’t too hot.
  • Learn more tips on harvesting broccoli.

How to Store Broccoli

  • Store broccoli in the refrigerator for up to 5 days.
  • If you wash before storing, make sure to dry it thoroughly.
  • Broccoli can be blanched and frozen for up to one year.

Spacing for Broccoli

Recommended Varieties

Wit & Wisdom

  • Originally, broccoli was eaten for its stems.
  • Early Roman farmers referred to broccoli as “the five green fingers of Jupiter.”
  • Once you’ve gotten broccoli down pat, why not try growing one of its relatives? See our Growing Guides for cauliflower, cabbage, brussels sprouts, rutabaga, kale, and turnips!

Recipes

Cooking Notes

One ounce of broccoli has an equal amount of calcium as one ounce of milk. Learn more about the amazing health benefits of broccoli

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Growing Broccoli

Botanical Name Brassica oleracea, Italica group
Plant Type Vegetable
Sun Exposure Full Sun
Soil Type Sandy
Soil pH Slightly Acidic to Neutral
Bloom Time
Flower Color Yellow
Hardiness Zones 3, 4, 5, 6, 7, 8, 9, 10
Special Features