Jefferson Seed Library

Cauliflower

Cauliflower is a cool-weather crop that can be grown in spring or fall. Cauliflower has a wide range of culinary uses and is good both raw and cooked. 

  • Variety
Snowball Self-Blanching; Snowball X
  • Scientific Name
Brassica oleracea
  • Growing Level
Difficult
  • Seed Saving Level
Intermediate to Difficult
  • Seed Storage
5 years if stored properly
  • Life Cycle
Biennial
  • Germination Time
7-14 days
  • Height & Spread
20” tall x 16” spread
  • Light Requirements
Full sun
  • Days to Harvest
65-80 days
  • Harvest
up to 7” diameter head
  • “Check Out” Month See Upcoming Events for specific “check out” dates.
February, March, June, July, August
  • In Stock?
Yes

 

Cauliflower

Growing Tips

Difficult Growing

Container Friendly

For large containers–5 gal

When to Start

Spring: Start indoors or direct sow 12-13 weeks before the last frost date. (End of January/Beginning of February for GA.)

Transplant: 6-8 weeks before the last frost. (Mar 1 – Apr 1 for GA)

Fall: Either direct sow or start indoors in mid-summer. (July 15-Aug 15 for GA)

 

How to start

 

To start indoors, use sterile, pre-moistened seed starting mix. Sow seeds to a depth of 1/4 to 1/2 inch into seed cells 12-13 weeks before the last frost. Then place them under grow lights. Or direct sow 12-13 weeks before the last frost. Just use row covers to protect from any freezes.

Transplant after hardening off 6-8 before the last frost.  

Care

 

Cauliflower likes well-draining soil and dislikes temperatures above 75 F. Plants tend to bolt at these temps. They like full sun but can tolerate some partial shade.

As a cool weather plant, cauliflower prefer temperatures between 65-75 F. Late freezes can ocure, and plants will need to be protected from freezing temperatures. Using row covers and mulch, will provide a good amount of protection. Plant or thin 2 feet apart with rows 3 feet apart.

 

Blanching

 

White cauliflower should be blanched, while green, orange, and purple cultivars need the sun to develop their colors. To blanch white cauliflower, tie the outer leaves loosely over the developing head with a soft cloth or rubber bands, when the head is about a golf ball to tennis ball size. This will protect it from sunscald and keep it from turning yellow. Make sure the heads are dry to prevent trapping moisture and encouraging fungus growth.

Blanching is the technique of covering a plant or plant part to prevent the development of color. This is what gives the vegetable its creamy white color. If you don’t blanch, the curds will be greenish-brown rather than white and the flavor will be stronger, almost bitter.

Example of blanching

Harvest

 

Cauliflower is ready to harvest a week or two after blanching or covering the heads. Check the heads every couple of days. Harvest when the heads are 6 plus inches across but before the flower parts begin to separate. Cut the cauliflower from the plant with a large knife, leaving at least one set of leaves to protect the head.

Seed Saving

Isolation Distance

 

Insect-dependent and biennial, cauliflower will cross with other Brassica oleracea like kale, collards, and broccoli.  Separate by 1 mile for reliable distance isolation. Cauliflower plants are mostly self-infertile and should be planted in groups of 10 or more plants for continuing viability. Allow seeds to mature and dry on the plants before harvesting.

 

Instructions

 

Cauliflower requires vernalization (the process of overwintering). Designate a particular cauliflower plant or plants for seed harvest. Because the flowering head of the cauliflower plant is harvested for consumption before its many buds bloom, you must leave certain ones intact to harvest the seeds.

Plants will bloom in the 2nd year. Dig up the seed plants at the end of the first growing season if the winter low temperatures fall below 32 F. In this case, replant them in pots of sand. Store the sand pots over the winter in a temperature range between 32-40 F. Transplant the seed broccoli back to the garden the following spring.  You MIGHT be able to get away with leaving the cauliflower in the ground in GA. Mulch heavily and cover if temps get below freezing.

Pull the seed stalks after the long seed pods become dry and brittle and the entire plant turns brown. Strip the pods from the stalks and place them in a bowl. Work through the bowl of seed pods with your fingers. The pods will easily open, releasing the tiny brown seeds. Stand outside and winnow the chaff by blowing across the surface of the bowl or using a fan or hair dryer set on cool, or even the breeze, to blow away the empty seed pods.

Allow seeds to dry on the plant before harvesting. Store them in a dry place and wait until they are thoroughly dry. Seeds and finer chaff are easy to separate by a variety of methods. One way is to use two screens of varying mesh, one a little smaller than the seeds and the other a little larger. The first screen lets anything smaller than the seeds fall through, and the second lets the seeds through and stops anything larger.

Features

  • Snowball Self-Blanching: Heirloom. Heads are 6-8 inches. Leaves will curl up and self-wrap the heads when cooler weather comes.
  • Snowball X: Pure white heads. 

When harvesting cauliflower, you are harvesting the flower. In order to save seeds, you must leave the flower head on the plant for seeds to form in the second year. It’s also not necessary to blanch. Just let the flower go to seed. 

Sources:

Starting & Saving Seeds By Julie Thompson-Adolf

Gardeningknowhow.com