Broccoli, a member of the brassica family, is a nutritional powerhouse, offering anti-inflammatory and antioxidant benefits that could help reduce the risk of cancer and other ailments.
If you're curious about growing broccoli, rest assured it's one of the simplest crops to cultivate. Depending on the variety you choose, you can enjoy fresh harvests from spring through early winter, making it an essential part of your seasonal garden and culinary plans.
This plant thrives best in open ground due to its long taproot, which doesn't adapt well to smaller pots.
Types of Broccoli to Know
When planning your vegetable plot, consider the two main types of broccoli. Calabrese, known for its large green heads and thick stalks, is the most common variety. True or sprouting broccoli features smaller florets that grow on slender shoots, with purple sprouting broccoli being the most recognizable.
Calabrese has a milder taste and a longer growing season than sprouting varieties. If properly cared for, you can reap multiple harvests from calabrese plants from summer to fall.
“Calabrese is incredibly easy to grow in any fertile, well-drained soil with plenty of sunlight,” says gardening expert Guy Barter, author of Growing Vegetables & Herbs (RHS).
True or sprouting broccoli has a distinct, nutty flavor. You can consume both the shoots and the heads by trimming the tops and removing any yellowing leaves. Sow sprouting broccoli from April to July for an early crop the following year or in mid to late spring for a winter harvest.
Cape Broccoli is another variety known for its impressive size and color. “It produces one large, flavorful purple head in late winter, just before it begins to sprout,” notes Guy Barter.
Growing Calabrese Broccoli
Calabrese is straightforward to plant, grows rapidly, and can be harvested within four to five months in the summer. You can extend its availability into fall through successive sowing. These hardy, frost-resistant plants often produce a second head, leading to a second harvest from the same plant.
Sow calabrese from March through August in neutral soil enriched with compost or manure. After raking, walk over the soil to create a firm base for planting.
If you're also interested in growing French beans, they can be sown around the same time, making a great addition to your garden.
Direct Sowing Broccoli Seeds Outdoors
You can sow broccoli seeds either in trays or directly into your prepared garden bed. Direct sowing is ideal if you're starting in May—just ensure there's no frost risk or protect your young plants from cold spells.
For similar harvests, check out how to grow kale, another nutritious brassica that can be sown indoors or directly in the soil.
“If spaced adequately, broccoli can produce throughout summer and fall due to side shoots that grow after harvesting the main stem,” explains Guy Barter, Chief Horticultural Adviser at the Royal Horticultural Society. Proper spacing allows roots and plants to expand, resulting in larger broccoli heads.
Starting Broccoli Seeds Indoors
For an early start, sow seeds in trays indoors to shield them from cold and frost. Plant indoors between March and April, then transfer them outdoors in June or July.
Acclimating Broccoli Seedlings for Planting
You must 'harden off' your seedlings before planting them outside. Start by moving them from a warm area to an unheated space for two or three days.
Over the next eight days, gradually expose the plants to outdoor conditions, increasing their time outside each day. Alternatively, you can cover them with a cloche for protection.
Planting Your Broccoli Seedlings
Grow your broccoli in a sheltered patch or raised bed that gets both sun and some light shade. To prevent disease, avoid planting where other brassicas have recently been grown; however, planting where peas and beans have been is beneficial as they enrich the soil with nitrogen.
Space your seedlings 24 inches apart, or 15 inches for smaller varieties. This spacing is crucial for a robust root system and strong foliage. It also allows for the development of side shoots, which can produce additional heads.
To plant, dig a hole matching the size of the seedling, place it in the hole, and gently firm the soil around the stem. Water thoroughly.
When should you plant broccoli? Plants set in the ground during June and July will be ready for harvest from August to October.
Potatoes are another easy-to-grow option that pairs well with broccoli, as they utilize water and nutrients from different soil layers.
Protecting Your Broccoli Plants
Broccoli plants can grow large, so securing their roots is vital. Using supports can help them stay upright.
A frame covered with insect-proof netting is excellent for safeguarding against pests like cabbage whites, aphids, and cabbage root flies. Additionally, netting can protect the heads from hungry birds.
Caring for Broccoli Plants
Regularly water your plants to maintain moisture without waterlogging. Feeding them with nitrogen-rich liquid fertilizer can also boost growth.
During warmer months, apply mulch around the plants to help keep them cool.
Use a hoe to manage weeds and loosen the soil. Remove any yellow leaves to minimize the risk of fungal issues.
Harvesting Broccoli
When is the right time to harvest? Calabrese broccoli is ready from late summer to late fall. Cut the heads when they reach about 6-7 inches in diameter, ensuring the buds in the florets remain tightly closed. This is typically 7-8 weeks after planting. “Calabrese can quickly bolt, so timely harvesting is essential,” says RHS expert Guy Barter.
To harvest, use a sharp knife to cut the stalk around 6 inches below the head.
After harvesting, the plant will produce side shoots with smaller heads that can be picked and enjoyed. Cut these when they reach about 4 inches long. The more you harvest, the more shoots will grow, leading to a longer, more fruitful harvest.
Growing Purple Sprouting Broccoli
This winter and spring-harvesting true or purple sprouting broccoli is often regarded as the finest of the brassicas, boasting a rich, nutty flavor.
“For homegrown purple sprouting broccoli, sow the seeds in spring and transplant the young plants in mid-summer,” advises expert Tom Petherick, author of Sustainable (Pavilion). “They thrive in most soils but may need staking if your garden is exposed to wind.”
Sow in mid-spring for summer and fall varieties, and in late summer for overwintering purple sprouting broccoli.
Follow the same planting, transplanting, and care guidelines for purple sprouting broccoli as you would for calabrese.
Harvesting Purple Sprouting Broccoli
Harvest shoots as soon as they’re ready—the buds on the small florets should still be closed. You can continue to harvest for several weeks.
Is Broccoli Easy to Grow?
Broccoli is generally a straightforward crop, but it does require ample space for proper growth. The plants are sizable and must be spaced adequately for optimal development.
Cooking Broccoli
Calabrese broccoli should be steamed lightly until tender yet still slightly firm. Alternatively, blanch it in boiling water for three minutes before stir-frying.
For purple sprouting broccoli, blanch it for three minutes, then cool it to retain color and crispness. It should be tender outside but still firm inside. Roasting the stalks with olive oil can deepen the flavor, and you can enhance it with orange or lemon juice, chili flakes, or sesame oil.
