Days to germination: 4 to 10 days
Days to harvest: 60 to 100 days
Light requirements: Full sun or partial shade
Water requirements: Frequent watering needed
Soil: Rich and well-drained
Everyone is familiar with white cauliflower, but you can experiment with purple, green and orange types too.
The white portion in the middle of the plant is usually referred to as the “curd” or just the head of the cauliflower. Read through the growing instructions because your plants may need some help to turn white. Don’t assume they just naturally grow that way.
Cauliflower is eaten cooked as often as it is raw, and has almost an entire day’s worth of vitamin C in a cup of vegetable. It also has vitamin K, folic acid and fiber. The colored varieties have more nutrients in them than the white ones. Orange cauliflower is particularly high in beta-carotene. Regardless, cauliflower is very low in calories.
Starting from Seed
Plants should be started indoors from seed, because they will not mature in time to beat the summer heat if you want to seed them directly into the garden.
Start your seedlings about 6 weeks before your last frost date. Use 3″ pots for your seedlings instead of those little seedling trays. Cauliflower is a bit delicate when transplanting, so you want to provide a good amount of earth around the roots. Plant your seeds a quarter of an inch into the potting soil and keep them warm until the plants begin to sprout.
If your growing season is long enough, you can also plant a fall crop to take advantage of the later cool weather. The right time for direct seeding will still be too hot for cauliflower, so even a fall crop should be started indoors. In this case, start the seedlings approximately 12 to 14 weeks before your expected date of first frost.
Before planting, dig up your cauliflower patch so the soil is loose and mix in some organic matter like compost or aged manure.
For your spring seeding, put your seedlings into the garden just after the threat of frost is past. In the fall, you can put them out roughly 4 to 6 weeks after you started them. Ideally after the hottest weather is over but with enough time in the season to mature before winter.
Your plants will grow larger heads if you give them plenty of space in the garden, but you’ll have more plants if they are closer together. You will have to make that decision based on your garden size. Give them 6 inches of space at a minimum, allowing up to 2 feet.
Dig holes for your seedlings deeper than their current container and bury the plants right up to the lowest leaves. This is always a good technique for plants with shallow roots.
While your plants are growing, keep them well-watered and you can use a low-nitrogen fertilizer if you wish. Too much nitrogen can cause your plants to develop hollow spaces in their stems which can kill them.
The tricky part of growing cauliflower comes later in the season when the heads of curd begin to form. You need to protect the curd from the sun in order for it to turn white. The easiest way is to plant a “self-blanching” variety of cauliflower like Snow Crown, that naturally grow their leaves over their curds.
For all of the varieties that stay open, you will have to cover the heads yourself. The typical procedure is to bend the large outer leaves up over the plant and tie them in place. You don’t necessarily have to tie them as long as they stay in place. Don’t wrap the head up so tightly that it can’t grow either.
Do it when the small heads are between 4 to 8 inches across. Once tied up, watch your plants carefully. When the curds are white you can start to harvest them. They will turn white after just a few days, so don’t leave them alone for too long after you tie them. If you see the curds starting to grow apart, they need to be taken immediately.
If you are growing self-blanching varieties, still keep an eye on the plants. You risk having your crop ruined if the leaves don’t fully cover the growing curd. Just don’t make any assumptions, and if you have to pull a few leaves up over the heads, then do so to protect your cauliflower.
Unlike the blanching you do with celery, its not just for looks with cauliflower. If left alone, the heads will turn yellow and be too strongly flavored to eat.
Growing cauliflower in containers will usually work as long as the container is at least 8 inches deep (12 inches is better). No special instructions are necessary for container gardening, other than more frequent watering may be necessary as your plants will dry out faster.
Pests and Diseases
As part of the same plant family, cauliflower is prone to the same problems as cabbage, broccoli and Brussels sprouts. For this reason, rotate your crops around the garden area so that these plants aren’t in the same place every year.
Root maggots can be a problem if you see your plants wilting and dying for no reason you can see above ground. These little white maggots hatch from eggs laid in the soil, and then feast on the roots of your plants. Dig up a suffering plant and see if there are small worms through the roots. You can’t do anything for the plants except pull them up.
Keep the flies away from your plants with fine mesh covers while they are growing. Plants close to maturity can usually withstand a little maggot damage, so the covers can come off.
Another insect pest is the cutworm. It looks like an average caterpillar but can chew right through the tender stalk of a seedling. Pick them off your plants if you see them, and you can take an extra step of putting a foil or cardboard collar around the stems. They are usually only a spring-time threat.
Harvest and Storage
A few days after you’ve tied up the leaves, your cauliflower heads should be white and ready to harvest. Though you can start blanching your cauliflower any time the heads are large enough, you should try to get them all done before the hot weather of summer takes off. Cauliflower doesn’t like the heat and will bolt to seed when it gets hot.
If you have a short season, try an early variety like Cashmere or Rushmore. They will mature just over 50 days. Most others will be closer to 75 to 100 days.
Just slice the whole head off from the plant, near where the stalk meets the soil.