CAULIFLOWER SOWING, PLANTING, GROWING, AND HARVESTING
BOTANICAL NAME: Brassica oleracea
PLANT TYPE: Vegetable
SUN EXPOSURE: Full Sun
SOIL TYPE: Loamy
SOIL PH: Slightly Acidic to Neutral
FLOWER COLOR: White
BLOOM TIME: Spring
Cauliflower is a cool-season crop and a descendant of the common cabbage. It is more difficult to than its relatives because it does not tolerate the heat or cold as well. For this reason, cauliflower is usually grown commercially.
If you plant to attempt growing cauliflower in the home garden, it requires consistently cool temperatures with temperatures in the 60s. Otherwise, it prematurely “button”—form small button-size heads—rather than forming one, nice white head.
When to Start
Broccoli seeds are best started indoors 7 to 9 weeks before the last frost, at a temperature of 70 to 75 degrees F. They can also be sown outdoors 2 weeks before the last frost. For a winter crop in zones 8 and warmer, sow in late summer. Expect germination in 10 to 14 days.
The same guidelines apply to Cauliflower, except when starting indoors, sow your seeds 5 to 7 weeks before the last frost. Expect germination in 8 to 10 days.
Since Cauliflower is more sensitive to cold than its cabbage-family relatives, you need to start it early enough that it has a chance to mature before the heat of the summer. Be careful, however, not to start it so early it gets damaged by the cold.
How to Start
Sow your Broccoli and Cauliflower seeds at a depth of 4 times the size of the seed, or ½ inch deep, and water thoroughly. Once the seeds have sprouted, be sure to keep the soil lightly moist.
Make sure the plants receive plenty of light -- fluorescent light for around 14 to 16 hours a day is also ideal for the fastest growth. You will want to keep the seedlings just a few inches below the light so they don't“stretch”and get“leggy". If you don't have fluorescent lighting, a south-facing window will do just fine.
Broccoli -- 45 to 60 days from sowing to harvesting
Cauliflower -- 30 to 80 days from sowing to harvesting
If your seedlings have been held too long or mistreated in some way before planting, they can create“buttons”, or small heads, that tend to flower prematurely.
Climatic elements such as extreme cold and drought can cause your plants to halt their full growth and form only “buttons”.
Don't allow your transplants to get too mature before moving them to your garden. If you do, they may become stressed by transplant shock.
A starter fertilizer applied when you transplant your seedlings will get your Broccoli and Cauliflower off to a good start, but it will not compensate for all the possible problems just mentioned.
Beets, Onions, and Garlic are all good companions for your Broccoli and Cauliflower.
- Broccoli -- once the head is fully developed, but before the individual flowers start to open, cut the central head along with 5 or 6 inches of stem. Removing the central head will stimulate development of the side shoots, which will allow you to continue your harvest for several weeks.
- Cauliflower -- the heads (curds) develop quickly under proper conditions, typically growing to 6 to 8 inches within 7 to 12 days after branching begins. Harvest the mature heads (they should be compact and firm) by cutting the main stem. If the heads develop a coarse,“ricey”appearance, they have over-matured. Cauliflower does not typically have side shoots, so you can compost the plants after the heads have been harvested.
- Store fresh, unwashed Broccoli in your refrigerator's vegetable crisper for 3 to 5 days. Put it in a loose or perforated plastic bad, being sure not to store it if it's wet -- wet Broccoli will quickly become limp and can get moldy. Its best flavor and nutritional value will be maintained if storage is brief.
- Uncooked Cauliflower can be stored in a paper or plastic bag in the refrigerator for up to a week. Place it stem side down to keep moisture from collecting in the florets.
- Select a site with at lesat 6 hours of full sun.
- Soil needs be very rich in organic matter; add composted mature to the soil before planting. Fertile soil holds in moiture to prevent heads from “buttoning.”
- Test your soil! (Get a soil test through your cooperative extension office.) The soil pH should be between 6.5 and 6.8.
- It is best to start cauliflower from transplants rather than seeds. Transplant 2 to 4 weeks before the average frost date in the spring, no sooner and not much later.
- Space the transplants 18 to 24 inches apart with 30 inches between rows. Use starter fertilizer when transplanting.
- Plant fall cauliflower about the same time as fall cabbage. This is usually 6 to 8 weeks before the first fall frost and also need to be after the temperature is below 75 degrees F.
- If you really want to try starting cauliflower from seeds, start the seeds 4 to 5 weeks before the plants are needed. Plant the seeds in rows 3 to 6 inches apart and ¼ to ½ of an inch deep. Do not forget to water the seeds during their germination and growth. Once they become seedlings, transplant them to their permanent place in the garden.
- In early spring, be ready to cover your plants with old milk jugs or protection if needed. For fall crops, shade them if they need protection from the heat.
- Add mulch to conserve moisture.
- Make sure that the plants have uninterrupted growth. Any interruption can cause the plants to develop a head prematurely or ruin the edible part completely.
- Cauliflower requires consistent soil moisture. They need 1 to 1.5 inches of water each week; with normal rainfall, this usually requires supplement watering.
- For best growth, side-dress the plants with a nitrogen fertilizer.
- Note that the cauliflower will start out as a loose head and it takes time for the head to form. Many varieties take at least 75 to 85 days from transplant. Be patient.
- When the curd (the white head) is about 2 to 3 inches in diameter, tie the outer leaves together over the head with a rubber band, tape, or twine. This is called blanching, and it protects the head from the sun and helps you get that pretty white color.
- The plants are usually ready for harvest 7 to 12 days after blanching.
- Cabbageworm: Nectar from dwarf zinnias lures ladybugs and other predators that help to protect cauliflower from cabbageworms.
- Cabbage root maggots
- Harlequin bugs
- Black rot
- When the heads are compact, white, and firm, then it is time to harvest them. Ideally, the heads will grow 6 to 8 inches in diameter.
- Cut the heads off the plant with a large knife. Be sure to leave some of the leaves around the head to keep it protected.
- If the heads are too small but have started to open up, they will not improve and should be harvested.
- If the cauliflower has a coarse appearance, it is too mature and should be tossed.
- If you want to store cauliflower, you can put the head in a plastic bag and store it in the refrigerator. It should last for about a week.
- For long-term storage, you can also freeze or pickle the heads.
- ‘Snowball’, which produces medium heads and a good yield throughout the growing season.
- ‘Orange’, which has a similar taste to the white cauliflower but has more vitamin A.