Growing and Saving the Seed of Cauliflower

Cauliflower is a refined relative of cabbage harvested when the buds of its head are developed but unopened. The undifferentiated, grainy mass is referred to as “curds.”



Cauliflower has been mentioned as far back as the 6th century B.C. It has long been considered a delicacy because of its superb flavor and high price, and it comes in a range of colors from white to yellow, to purple and green. 


  • A wide range of culinary uses




  • Sow ¼ to ½ inch deep.


  • Ideal germination temperature range is 50-75 F.

  • Seeds germinate in 7-10 days.

  • Sow seeds indoors 6 to 8 weeks before last frost, or direct seed outdoors 6 to 8 weeks before last frost date and again in midsummer for fall harvest.

  • For multiple successions, sow once a month until July, or grow varieties that mature at different times. In milder climates, cauliflower can be sown in late June/early July, and be transplanted in August.

  • With at least 4 to 6 sets of leaves, cauliflower can overwinter in a mild climate and set heads in early spring March/April.




  • Cauliflower requires rich, moist, well-drained soil with a pH between 6 and 7.
  • Cauliflower likes full sun but prefers cool conditions with an ideal growing temperature of between 65 and 80 F.
  • Space seedlings 18 to 24 inches apart, in rows 36 inches apart.
  • Some varieties splay their leaves more than others. When the white head is exposed for long periods before being harvested, it can be damaged by the sun or extreme rain. One way to secure a tight, white cauliflower head is to “blanch” the heads by loosely tying the leaves up above the curds to block sunlight. Exposure to sunlight will cause the heads to turn green and develop a strong, bitter flavor. Any major temperature swing can cause curds to become loose or leaves to sprout through the curd.
  • The best way to ensure perfect heads is to succession plant in early spring and again in mid-summer for a fall harvest. Curds are typically harvested at 6-8 inches across, though in some climates such as the Northwest, cauliflower is allowed to grow to 1.5 feet across before cutting!




  • Cauliflower, like other brassica crops, can experience cabbage worm damage. It can be managed the same way as with the other brassicas.
  • Bacterial soft rot is another common cauliflower problem. This appears on the curd in the form of what looks like a wet spot or darkened area, which gets progressively dark and soft.
  • This bacteria can be spread through tools and water irrigation, and it is common in warm, moist conditions. There are horticultural practices, such as crop rotation or harvesting when it is dry, that can help mitigate bacterial soft rot.


  • For a seed saving crop, isolate cauliflower from other brassicas (such as broccoli and kale) by one mile to avoid cross pollination.
  • Select your best plants to keep for seed and leave them to flower.
  • In short-season areas with harsh winters,  the plants can be mulched and left in the ground with a row cover, and in the second season the plant will send up flower stalks from the head. As they mature, they will become seed pods.
  • Once the plant has died back and the seed stalks/pods are brown and dry, pull the entire plant and hang it for up to two weeks in a dry, well-ventilated area.
  • Break open the seed pods with your hands or a rolling pin over a container such as a bowl or plate, and separate and extract the seeds.
  • Properly stored (keep them cool and dry!), the seeds of cauliflower and other brassicas will be viable for up to five years.