How To Grow Broccoli Seeds

How To Grow Broccoli Seeds

Updated on Jan 19, 2022
By Shannon McCabe

Broccoli is an Old World cabbage relative grown for its succulent flower heads or buds. It thrives in cool — but not cold — weather.

HISTORY

Descended from wild cabbage native to the Mediterranean coast, broccoli was bred by the Etruscans. Although Thomas Jefferson grew it at Monticello, broccoli would not become commercially grown in the U.S. until the 1920s. Prior to the turn of the century, purple broccoli was more common than green.

USES

  • A multitude of culinary uses

  • Sow seeds indoors about 4-6 weeks before last frost.
  • Sow seeds ½ inch deep in trays filled with good-quality potting mix.
  • You can also direct seed 2 to 3 weeks before last frost.
  • Ideal germination temperature is 75 F.
  • Seeds germinate in 8-10 days.

  • Remember that broccoli does not like extreme heat or cold; plants grow best between 65 and 80 degrees.
  • Transplant into the garden or thin to 1-2 feet apart. Avoid deeply cultivating seedlings, as they have shallow roots; try a thick layer of mulch instead to retain moisture and suppress weeds.
  • Keep plants moist, as plants do not tolerate drought.
  • You can plant a fall crop of broccoli in most regions of the U.S. Sow 80-100 days before the first fall frost date.
  • Harvest using a sharp knife when heads are firm and 3 to 4 inches across. Cut the main stalk and leave the plant intact to encourage the growth of side shoots (smaller heads that will grow after the main stalk has been harvested).

PESTS/SPECIAL CONSIDERATIONS

  • Like other cabbage relatives, broccoli is very susceptible to cabbage worm, cabbage loopers and diamondback moths.
  • To keep the pests at bay, apply BTK (Bacillius Thurengiensis var. Kurstaki) a naturally occurring, organic approved bacteria, every 1 to 2 weeks. Purchase beneficial wasps and release them in the garden to keep the population down. Interplant thyme with your plants; cabbage worms hate the smell!

  • Broccoli is considered to be a more challenging crop for seed saving. It is a biennial and will not flower until its second year of growth.
  • It is easy to keep broccoli alive over winter in climates where the winter is mild. Northerners will need to get creative; established broccoli is not tolerant of temperatures below 20 F.