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When to Plant Broccoli
Broccoli’s growing season book-ends peak summer with a spring planting and mid-summer harvest, and a late summer planting and mid to late-fall harvest. A cool-season crop like broccoli may be planted as soon as frost is no longer expected in early spring; these crops often fade, and may die altogether, during the heat of summer. A second window for planting cool-season crops opens up in late summer and early fall; once mature, these species can actually survive a light fall frost (in mild climates, they may even continue producing into the winter months).
How to Plant Broccoli
There are various types of broccoli, bred to be tolerant of heat or disease, primed for quick growth, or long stems. Calabrese, an Italian heirloom type of broccoli with particularly full crowns, is one of the more popular and common varieties. Consult a garden center to find the right varietal for your garden.
- Pick the site. Broccoli loves full sun, at least six hours worth per day, and requires a nitrogen-rich soil, with a slightly acidic soil pH of 6 or 7. Good soil moisture, with no sogginess, is key, so pick a spot with good drainage—that might mean raised garden beds.
- Prepare the site. A week before transplanting seedlings or sowing seeds, work compost or organic matter into the top layers of soil.
- Plant. Broccoli seeds should be planted ½-inch deep, spaced 3 inches apart, while seedlings should be further apart, more like 12 inches. Organize planting into rows with 3 feet of space between them, to encourage larger crowns; closer rows will mean smaller main heads, but more side shoots.
How to Care for Broccoli Plants
Broccoli requires consistent watering, about an inch per week, and intermittent fertilization, depending on the condition of the soil. When watering, be careful not to soak the crowns of the broccoli, which can trap water and lead to rot.
- Mulch. Mulching around the base of the plants will help control weeds.
- Fertilize. Side-dress with blood meal or a fertilizer to correct for depleted nitrogen levels, which may be the cause behind yellowing leaves.
- Companion plant. Aphids will suck the juices out of broccoli shoots. Companion planting can deter aphids, as can a quick leaf rinse with soapy water. Small green caterpillars called cabbage loopers, cabbage worms, maggots, and flea beetles wreak havoc on the leaves as well. If feasible, they can be picked off by hand, or treated en masse with Bacillus thuringiensis, a natural insecticide. Find our complete guide for broccoli companion planting here.
- Use row covers. Use floating row covers just after planting to help protect broccoli seedlings.
- Prevent infection. Clubroot, a condition caused by a fungal infection, will manifest as fast-wilting plants and misshapen roots. In this case, the entire plant and root system will need to be dug up quickly to prevent spreading.
How to Harvest Broccoli
Harvesting broccoli is best done first thing in the morning when the broccoli heads are tight and firm.
- Watch for flower buds. The perfect time to harvest is right before the broccoli flowers. Look for closed flower heads; yellow flowers mean the quality clock is already counting down, so harvest immediately.
- Cut on a diagonal. A horizontal cut allows water to pool on the exposed stem, which can rot the plant from the inside out and prevent any of the smaller side shoots from flourishing. Instead, use a sharp knife to make a slope and allow water run-off.
- Don’t forget the stem. Include at least 6 inches of stem per broccoli head. Leave any side shoots to finish developing, and then harvest those, too!
Think Like a Pro
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