Umpqua - Broccoli Seeds

Start seeds indoors about 5–7 weeks before transplanting. Set spring plants outdoors roughly 3–4 weeks before the expected last frost once they are hardened off and conditions are reasonably settled.

Broccoli forms its best heads in cool weather and may struggle when heads mature during sustained heat. For a fall crop, count backward from the variety’s days to maturity and allow extra time for slower autumn growth.

Sow seeds ¼–½ inch deep in moist seed-starting mix. Provide bright light after emergence and keep seedlings growing steadily in cool, moderate conditions.

Harden plants gradually before transplanting and space them about 18–24 inches apart. Avoid holding seedlings too long or exposing large transplants to prolonged cold, which can lead to small, premature heads.

Choose a site with full sun and fertile, well-drained soil enriched with finished compost. Maintain balanced fertility and avoid excess nitrogen, which can encourage leafy growth at the expense of firm heads.

Keep the soil evenly moist, especially while heads are forming, and mulch with clean straw, shredded leaves, or another organic material. Drought, root disturbance, and sudden swings in growth can reduce head size and quality.

Harvest when the central head is full, firm, and tightly closed, before individual buds loosen or show yellow flowers. Cut the head with several inches of tender stem attached.

Leave the plant in place after the main harvest. Many varieties will produce smaller side shoots for several additional pickings, especially during cool weather.

Broccoli provides fiber, folate, vitamins C and K, carotenoids, and potassium. Like other brassicas, it also contains naturally occurring sulfur-rich compounds called glucosinolates.

The florets, peeled stems, and young leaves are all edible. Broccoli may be eaten raw, steamed, roasted, stir-fried, added to soups, or blanched and frozen.

Cabbageworms, loopers, and other caterpillars may chew leaves or hide inside developing heads. Check plants often, remove eggs and caterpillars by hand, and use insect netting from the time plants are set out where these pests are common.

Flea beetles and aphids may also appear on young plants. Strong seedlings, crop rotation, clean beds, good airflow, and nearby flowers that support beneficial insects help keep problems in balance. Water at soil level and avoid planting brassicas in the same place year after year to reduce disease pressure.

Broccoli is an insect-pollinated biennial and usually flowers after experiencing winter cold. It crosses with other Brassica oleracea crops, including cabbage, cauliflower, Brussels sprouts, collards, European kale, and kohlrabi.

Save seed only from open-pollinated plants that show the desired head, vigor, and maturity. Grow only one flowering B. oleracea variety nearby, or provide generous isolation. Allow several plants to flower for better genetic diversity.

When the second-year pods turn tan and begin to dry, cut the stalks before they shatter. Finish drying them under cover, then thresh, clean, and store the fully dry seed in a cool, dark place.

• Fall crops often produce larger, tighter heads than spring crops.
• Protect young plants early where caterpillars are common.
• Harvest promptly once the buds begin to loosen.
• Leave the stem after harvest for side shoots.
• Follow broccoli with a non-brassica crop or soil-building cover crop.