Cauliflower is a cool-season vegetable that thrives in sunny spots with fertile, well-drained soil. First, let us summarize how to grow cauliflower. Before planting, mix plenty of organic matter and a complete fertilizer. Sow seeds ¼-½ inch deep, 2-3 weeks before the last frost. Space seedlings or transplants 12-18 inches apart in rows 2-3 feet apart. Avoid planting during the summer heat, as it can reduce yield and quality. Water deeply and infrequently, and use plastic or organic mulches to conserve moisture and minimize weeding. Monitor for insects and diseases throughout the growing season. Tie the leaves over the head to maintain color. Harvest cauliflower when the heads are white, large, and compact.
Types of Cauliflower
Each type of cauliflower has its own taste, color, and nutrition benefits. These are:
- Graffiti: Purple cauliflower that is milder and sweeter compared to white varieties.
- Snowball: Produces smooth, white heads about 6 inches in diameter and offers a good yield throughout the growing season.
- Orange varieties: Varieties like ‘Cheddar’ and ‘Flame Star’ are creamier and sweeter than white cauliflower and contain more vitamin A.
When to Plant Cauliflower
Cauliflower grows best in fall because cool weather promotes better head formation, though you can also grow it in spring. We recommend buying cauliflower seedlings (or “transplants”) instead of starting from seed, as cauliflower can be finicky.
Spring Planting:
- Sow seeds indoors 4 to 5 weeks before the last spring frost date.
- Plant seedlings outdoors 2 to 4 weeks before the last spring frost date.
Fall Planting:
- Plant a fall crop 6 to 8 weeks before the first fall frost date, but wait until daytime temperatures are consistently below 75°F.
How to Grow Cauliflower
Cauliflower can be more challenging to grow than other garden vegetables like kale and chard. Still, by following these simple steps on how to grow cauliflower, you can successfully cultivate this nutritious, fiber-rich vegetable high in vitamin C and other essential nutrients.
Enriching Your Soil
Cauliflower thrives in full sun and rich, moist, well-drained soil with a pH between 6 and 7. Prepare the soil by tilling it to 12-15 inches. Then, mix a 3-inch layer of nutrient-rich compost or garden soil into the top 6 inches of the native soil.
Planting Cauliflower
The quickest way to grow cauliflower is by starting with young plants, which brings you closer to harvest time right from the beginning. If you’re learning how to grow cauliflower from seed and starting indoors, wait until the seedlings have five leaves before transplanting them to your garden, which usually takes 4 to 6 weeks. Make sure to harden off the seedlings first by gradually exposing them to outdoor conditions for a few hours daily. Move them permanently outdoors two weeks before the last frost date, spacing each seedling 24 inches apart. If you’re planting directly outdoors, sow cauliflower seeds ½ inch deep and 24 inches apart, with rows spaced 3 feet apart.
Caring for Your Cauliflower
Water regularly to consistently moist soil, and apply a 3-inch layer of mulch to help retain moisture and keep soil temperatures cool. Regular feeding should be provided throughout the growing season to ensure cauliflower develops large heads.
Blanching White Cauliflower
If you’re growing a cauliflower variety with white heads, you’ll want to keep the heads bright white by covering them as they grow, a process known as blanching. When the head is about the size of an egg, pull the most extended leaves up and over it and secure them with twine or an elastic band. Purple, green, and orange cauliflower varieties don’t require blanching.
Harvest and Storage
The head is typically ready for harvest about a week after you tie up the leaves. Let it grow as long as it remains compact, ideally reaching a 6 to 8-inch diameter. You can untie the leaves to check on them and retie them if necessary. If the head starts to open up, cut it from the plant at the base of the neck, regardless of its size, as it will only decrease in quality. Once harvested, the head should stay fresh in the refrigerator for at least two weeks.
Problems With Cauliflower
Cauliflowers are often considered challenging to grow, but with the right approach, they can thrive. Understanding how to grow cauliflower involves ensuring the right conditions, such as firm, fertile soil and consistent moisture, and protecting the plants from brassica pests and diseases.
Providing Good Growing Conditions:
- Deformed or button heads and premature bolting (flowering) can occur due to various conditions interrupting growth, such as transplanting too late, root disturbance, loose soil, not securing transplants firmly, irregular or insufficient watering, cold spring temperatures, or hot summer weather.
- To prevent discolored heads, protect the developing curds from sun and frost, which can cause yellowing or browning, by folding the leaves over the head and securing them with string if needed.
Protecting Cauliflowers From Brassica Pests and Diseases:
- To protect your crop from most brassica pests, such as cabbage caterpillars, cabbage root flies, and pigeons, cover the plants with insect-proof mesh or fleece supported on canes and place brassica collars around the base of the stems.
- Safeguard seedlings and young plants from slugs and snails, and keep an eye out for aphids and whiteflies, removing them before they can multiply.
- To deter clubroot disease, lime must be applied to acidic soil to raise the pH to at least 7.5. If clubroot has been an issue, start your cauliflowers in pots to allow them to develop a strong root system before transplanting them into the ground.
