Broccoli – November Plant of the Month
Former President George H.W. Bush famously declared in 1990, “I do not like broccoli and I haven't liked it since I was a little kid and my mother made me eat it. I'm president of the United States and I'm not going to eat any more broccoli!" Most Americans don’t agree. In fact, in 2014 broccoli tied with beans as the 10th most consumed vegetable or vegetable product in the country.
Broccoli’s popularity is fueled by the fact it is a nutritional superstar. An excellent source of vitamins C and K, it’s also a good source of folate and Vitamin A, as well as healthful antioxidants and phytochemicals. Plus it’s a delicious and versatile veggie that can be enjoyed raw, steamed, roasted, and in everything from soup to salad to, yes, even smoothies!
Varieties: Broccoli is a cool season crop that thrives when day temperatures are in the 60s F. Choose varieties bred for better heat tolerance if your mild spring weather transitions to hot summer temperatures before the harvest is ready. Choose varieties bred for cold tolerance for fall and (in mild climates) winter harvests. Heading broccoli varieties, that form large central heads, are the most familiar. Sprouting broccoli varieties form many smaller, looser flower heads rather than one solid, central one.
Site: Full sun and fertile, well-drained soil. Broccoli does best in soil with a pH of 6.0-7.2. Growing in raised beds is a good option if your site is not well drained.
When to Plant: While you can direct seed broccoli right in the garden, success is more assured if you start seeds indoors and transplant seedlings to the garden when they have two sets of true leaves, large enough to better weather insect pests and outdoor temperatures. Start seeds in the spring 6 to 8 weeks before the last frost date in your area; transplant hardened off seedlings into the garden two weeks before the last spring frost date. For a fall crop, sow seeds 10 to 12 weeks before the first fall frost date. Gardeners in mild winter climates can sow succession crops in the fall for harvest throughout the winter.
Planting: Broccoli is a heavy feeder so work a few inches of organic matter into the soil before planting. Space seedling 15-20 inches apart and set them slightly deeper than they were growing in the container, up to their first set of true leaves.
Protect the stem of each plant with a cutworm collar. The simplest way is to wrap the seedling stem with several layers of 2- to 3-inch strips of newspaper. Cover the seedlings with a floating row cover to prevent damage from flea beetles and cabbage worms. If the temperature is forecast to dip below 50 degrees for more than a few nights, add some extras layers of row covers to prevent chilling injury that can lead “buttoning” or the formation of small heads.
Culture: Broccoli plants are shallow-rooted and do best with consistent soil moisture. A 3-inch deep layer of organic mulch will help retain soil moisture, keep weeds down, and avoid root damage that might occur when weeding.
Troubleshooting: Caterpillars such as cabbage worms, cabbage loopers, and diamondback moth caterpillars are common pests. Covering plants with lightweight row covers that let in light and water will exclude egg-laying female moths and can be left on all season. Or you can spray with the microbial insecticide Bt, which targets only caterpillars. Row covers will also offer protection from flea beetles that feed on leaves, especially early in the season. If cabbage aphids are a problem, knock them off plants with a strong stream of water from a hose or treat with insecticidal soap. Be sure to clean up all cabbage family members at the end of the season as these aphids overwinter on host plants. Club root is a fungal disease that stunts the roots. Keeping the soil pH around 7.0 will help to keep this disease in check.
Harvesting: Heading broccoli is ready to harvest as soon as the head, which is actually a cluster of unopened flower buds, is of a usable size and has a deep green color. Be sure to harvest when the flower buds have swelled, but are still tightly closed. Cut the main head with a 2 inch stem. On most varieties, smaller side shoots will then form that will extend your harvest.
Broccoli Rabe: Also called broccoli raab and rapini, this fast growing vegetable has a mildly bitter flavor. In spite of its name, it’s more closely related to turnips than broccoli. Sow seeds directly in the garden beginning in early spring as soon as the soil can be work, thinning seedlings to 4-6 inches. Make succession plantings through late summer or early fall, depending on your climate. Harvest edible stems, leaves and loose clusters of flower buds just as the buds begin to form.
Chinese Broccoli: Also known as flowering broccoli or gai lan, it produces thick, succulent stems topped with small flower heads similar to those of broccoli. Tolerant of both heat and cold, Chinese broccoli can be planted in succession throughout the growing season.
Romanesco Broccoli: This is actually a type of cauliflower, but is cultivated like heading broccoli. Its strikingly attractive, yellow-green heads look like a forest of miniature evergreen trees swirled in an intricate fractal pattern. They have a delicious, nutty flavor.
- When you eat broccoli florets, you’re actually eating flower buds! If you’ve ever seen broccoli plants left unharvested in the garden, you know that the buds in a head of broccoli go on to produce small, yellow flowers. You can also eat the stalk, which is composed of stem tissue.
- Broccoli is a member of the Cabbage family. In fact, in spite of how different they look, broccoli, cabbage, cauliflower, kale, Brussels sprouts, and kohlrabi are members of the same species – Brassica oleracea. They are, however, different botanical varieties within this species, testament to the extensive breeding and selection that’s gone on over the many centuries these vegetables have been cultivated.
- Thomas Jefferson grew broccoli in his garden at Monticello at least as early as 1767 with seeds imported from Italy.
- The name broccoli comes from the Latin “brachium,” meaning “arm,” referring to the many branches or arms that arise from the central stalk of the broccoli plant.
Check out this recipe for Banana Broccoli Smoothie.