Broccoli may be the most nutritious of all the cole crops, which are among the most nutritious of all vegetables. Broccoli and cauliflower (and other members of the genus Brassica) contain very high levels of antioxidant and anticancer compounds. These nutrients typically are more concentrated in flower buds than in leaves, and that makes broccoli and cauliflower better sources of vitamins and nutrients than cole crops in which only the leaves are eaten. The anti-cancer properties of these vegetables are so well established that the American Cancer Society recommends that Americans increase their intake of broccoli and other cole crops. Recent studies have shown that broccoli sprouts may be even higher in important antioxidants than the mature broccoli heads. Other research has suggested that the compounds in broccoli and other Brassicas can protect the eyes against macular degeneration, the leading cause of blindness in older people. If you choose to eat broccoli leaves, you will find that there is significantly more vitamin A (16,000 IU per 100 grams) versus flower clusters – the heads (3,000 IU per 100 grams) or the stalks (400 IU per 100 grams).
Vegetarians rely heavily on broccoli because it’s high in calcium.
IN YOUR GARDEN….
- Companions: Cilantro makes it grow REALLY well, bigger, fuller, greener! Lettuce amongst the Brassicas confuses Cabbage Moths which dislike Lettuce.
- Brocs prefer full sun, though partial shade helps prevent bolting (suddenly making long flower stalks).
- Brocs LOVE recently manured ground. Well-drained, sandy loam soils rich in organic matter are ideal. Broccoli plants will grow in almost any soil but prefer a pH between 6.0 and 7.0 for optimum growth. A pH within this range will discourage clubroot disease and maximize nutrient availability.
- Seedlings should be 8″-10″ apart with 30″-36″ between the rows. Broccoli yields and the size of broccoli heads are affected by plant spacing. The tighter the spacing the better the yields, but the broccoli heads will be smaller. If you intend to keep your plants for side shoots, plant taller varieties to the northmost so they won’t shade shorter summer plants you will soon be planting.
- Mulch will help keep the ground cool and moist as well as reduce weed competition.
- An even moisture supply is needed for broccoli transplants to become established and to produce good heads. Never let the seedbed dry out. In sandy soils this may require two to three waterings per day.
- Put a ring of nitrogen around cabbage, broccoli and cauliflower plants, to grow bigger heads.
- The center head produced by broccoli is always the largest. The secondary sprouts produce heads about the size of a silver dollar. Sidedressing with fertilizer can increase yields and size your side shoots.
- Cool weather is essential once the flower heads start to form. It keeps growth steady.
Brocs are truly susceptible to aphids. Yuk. Grayish greenish soft little leggy things that blend right in with the side shoot florettes. If you snap your fingers on the side shoot, you will see the aphids go flying. Those side shoots I remove. If aphids are in curled leaves, I hold the leaf open and hose them away with a strong burst of water! Then I keep my eagle eyes on them, each day, checking to get rid of them before another colony forms.
Important planting tip: There are less aphids when you plant different varieties of brocs together!
Broccoli varieties vary considerably, tall, short, more heat tolerant or cold tolerant, some make tons of side shoots, small heads, large heads! For smaller heads, grow quick maturing varieties. Packman is the exception!
Cruiser 58 days to harvest; tolerant of dry conditions
Calabrese 58 – 80 days; Italian, large heads, many side shoots. Loves cool weather. Does best when transplanted outside mid-spring or late summer. Considered a spring variety. Disease resistant.
DeCicco 48 to 65 days; Italian heirloom, bountiful side shoots. Produces a good fall crop, considered a spring variety. Early, so smaller main heads.
Green Comet 55 days; early; hybrid, 6” diameter head, very tolerant of diseases and weather stress. Heat tolerant.
Green Goliath 60 days; heavy producer, tolerant of extremes. Prefers cool weather, considered a spring variety.
Nutribud, per Island Seed & Feed, is the most nutritious per studies, having significant amounts of glutamine, one of the energy sources for our brains! Purple broccoli, in addition to this, contains anthocyanins which give it its colour. These have antioxidant effects, which are thought to lower the risk of some cancers and maintain a healthy urinary tract as well.
Packman 53 days; early hybrid, 9” head! Excellent side-shoot production.
Waltham 29 85 days; late, cold resistant, prefers fall weather but has tolerance for late summer heat.
If you still want to plant broccoli now, January, be mindful of the days to maturity, and when you think you will be wanting space to start your spring for summer plants. When it gets late in their season, cut lower foliage off so small summer plants can start under them while you are still harvesting your winter plants. The days to maturity on seed packs starts with when you put the seed in the soil. The days to maturity on transplants is from the time of transplant. And broccoli is notorious for uneven maturity, so you will often see a range of days to maturity, like DeCicco above. So don’t expect clockwork.
Harvest the main head while the buds are tight! Cut about 5” down the stem so fat side branches and larger side shoots will form. Cut at an angle so water will run off, not settle in the center and rot the central stalk.
The respiration rate of freshly harvested broccoli is very high, so get it in the fridge asap or it goes limp! It should not be stored with fruits, such as apples or pears, which produce substantial quantities of ethylene, because this gas accelerates yellowing of the buds.
Dying parts of the Brassica family of plants produce a poison that prevents the seeds of some plants from growing. Plants with small seeds, such as lettuce, are especially affected by the Brassica poison. A professor at the University of Connecticut says Brassica plants should be removed from the soil after they have produced their crop.
If you didn’t harvest your side shoots and your broccoli has gone to flower, harvest the flowers and sprinkle them over your salad, toss them in your stir fry for a little peppery flavor! You won’t get any more side shoots, but if you want seeds, leave the flowers, let the seeds come. Fine long little pods will form. Let them stay on the plant until dry, then harvest your seeds. Pop the pods, remove the seeds so no moisture will remain to rot them. This large species crosses easily though, so probably best to buy sure seeds unless you don’t mind mystery results!
The trick to producing excellent broccoli heads is to keep the broccoli plants growing at a strong steady pace. Top-dress the plants with compost or manure tea; or side-dress with blood-meal or fish emulsion; and water deeply. Repeat this process every 3-4 weeks until just before harvest! John Evans, of Palmer, Alaska, holds the world’s record for his 1993 35 lb (no typo) broc! He uses organic methods, including mycorrhizal fungi! And, yes, moose eat broccoli!