How to Grow Broccoli
Broccoli–as well as closely-related Brassica species like cabbage, kale, and spinach–is a cool weather crop. Thus, it is best to sow broccoli in early spring or autumn.
When growing broccoli in the spring, look to sow seeds indoors, in a greenhouse, polytunnel, or a cold-frame two or three weeks ahead of the last expected frost date.
For autumn or early winter crops, look to sow seed 85 days before the first frost’s expected or typical date.
Plant to a depth of 1-2 centimetres; sow seeds in planting compost in single plugs or 5-10 centimetres apart in a seedling tray.
Sowing the Seeds
Do not plant broccoli in the same place where another Brassica crop was grown the previous year. Rotating patterns of cultivation break up disease transmission from the soil. As different crops’ nutritional demands vary, it allows for different soil nutrients to be taken up or replenished every year.
Sow seeds 1-2 cm deep. The plants need at least 50 centimetres of space between rows to leaf out to their full potential.
Broccoli prefers a slightly acidic soil (6-6.8 pH), which is achieved by adding organic matter like compost.
Roughly three weeks after germination, broccoli transplants should be given a fertilizer boost that prioritizes soil inputs of nitrogen, calcium and potassium.
Maintaining Your Broccoli Plants
If the weather is too warm, a broccoli crop will “bolt,” producing a narrow stalk of flowers that blooms quickly. Since it is the unopened flower buds that are eaten as a vegetable, broccoli crops should be kept cool. In unseasonably-warm weather, use a shade cloth to protect Brassica plants like broccoli from the sun’s heat.
Mulching around the plants using decomposing organic matter like straw or wood chips will help suppress competitor plants and keep the soil below cool and moist. In times or situations without rainfall, a broccoli crop should be roughly watered once a week.
Broccoli Pests
Mulching around each plant with coffee grounds or eggshells, in addition to providing soil nutrition, can help keep slugs at bay.
An old gardener’s trick to deter the cabbage moth caterpillar—the bane of Brassica growers everywhere—is “companion-planting” rows or broccoli with marigolds (Tagetes spp.). Though evidence is anecdotal, their strong scent reportedly confuses adult butterflies looking to lay their eggs.
Another method is in using a “trap crop”: nasturtiums (Tropaeolum spp.) are closely-related to broccoli, and (again, anecdotally) cabbage moths with preferentially lay their eggs on the leaves of these edible blossoms, instead of a vegetable crop.
Alternatively, broccoli can be grown under a row cover, which keeps many pests out entirely.
Harvesting Broccoli
When the heads have reached a diameter of 12-15 centimetres (60-90 days after planting), it is time to clip them and harvest them. Side-shoots can be continually harvested for some time after the main head is clipped.
Broccoli Companion Planting
To ensure a healthy and productive broccoli harvest, it is important to consider companion planting.
Companion planting involves planting different types of plants together to create a mutually beneficial environment. Broccoli can benefit from a variety of companion plants that can help with nutrient uptake, pest control, and soil health.
Marigolds – Marigolds are a natural pest repellent and can help to keep aphids and other pests away from broccoli plants. Planting marigolds near broccoli can also help to improve soil health by adding organic matter and nutrients to the soil.
Beans & Peas – Both are legumes and can help to fix nitrogen in the soil, which can benefit the broccoli plants. Additionally, beans can help to suppress weeds and improve soil moisture retention, which can benefit the broccoli plants.
Lettuce – Another great companion plant for broccoli. Both plants have similar nutrient needs and can benefit from being planted together. Additionally, lettuce can help to provide shade for broccoli plants during hot weather, which can help to prevent the broccoli from bolting.
Chamomile – Chamomile can help to attract beneficial insects like hoverflies and parasitic wasps, which can help to control pests that may be harmful to broccoli plants. Additionally, chamomile can help to improve soil health by adding organic matter and nutrients to the soil.
In conclusion, companion planting can be a great way to improve the health and productivity of broccoli plants. By planting broccoli alongside companion plants like marigolds, beans, lettuce, and chamomile, gardeners can create a mutually beneficial environment that promotes healthy growth and provides natural pest control. Consider incorporating these companion plants into your broccoli garden for a bountiful and healthy harvest.
Try our Broccoli Varieties
- Green Sprouting Broccoli: also known as Calabrese, is a popular variety of broccoli that is known for its delicious flavor and high nutritional value. This variety produces large, blue-green heads that are tightly packed with small buds. The heads can grow up to 8 inches in diameter and can be harvested when they are firm and tight. Green sprouting broccoli is a cool-season crop that grows best in temperatures between 60-65°F. It is a highly nutritious vegetable, rich in vitamins A, C, and K, as well as fiber, potassium, and antioxidants. Green sprouting broccoli is a popular choice for both home gardeners and commercial growers, and can be used in a variety of dishes, including stir-fries, soups, and salads.
- Broccoli Rabe: Also known as rapini, is a green vegetable that is closely related to broccoli, but has a slightly bitter taste. It is commonly used in Italian cuisine and is a staple in many dishes, including pasta, soups, and stir-fries. Broccoli rabe has thin, leafy stems and small florets that resemble broccoli, but are more delicate in texture. It is a cool-season crop that grows best in temperatures between 50-60°F, and can be planted in the spring or fall. Broccoli rabe is a nutritious vegetable, packed with vitamins A, C, and K, as well as fiber and antioxidants. It is a great source of iron and calcium, making it a popular choice for vegetarians and vegans. Broccoli rabe is a versatile vegetable that can be cooked in a variety of ways, and its slightly bitter flavor pairs well with garlic, lemon, and parmesan cheese.
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