How and When to Harvest Cauliflower in the Fall Garden

Autumn weather causes green cauliflower stems to start forming their white sprouts—you’ll see your plants turn from leafy seedlings to bulging heads! Fall is perfect for growing cauliflower since the cool temperatures promote healthy head formation with little riciness or bolting. Join backyard grower Jerad Bryant and learn how to harvest your ready crop!

Written by Jerad Bryant Horticulture review by Sarah Jay Last updated: October 8, 2024 | 5 min read

Close-up of a hand in a pink glove harvesting cauliflower in a sunny garden.

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Cauliflower is nutritious, delicious, and gorgeous! It is an excellent crop for ornamental and vegetable garden beds, as the architectural form grows tall with other plants. It towers over tomatillos, tomatoes, and onions, creating a massive bundle of florets to eat and enjoy.

Its heads are tight bunches of flower sprouts that have yet to open. The sprouting rosettes form tight heads like broccoli, except they ripen into colors like white, green, purple, and orange. Cauliflower is in the same genus as broccoli Brassica and is native to the Mediterranean. Although it grows similarly to other members of the genus, like broccoli and cabbage, it’s a bit more challenging to cultivate than its relatives.

Fear not, as these harvesting tips and tricks will have you cutting down giant cauliflower throughout autumn. They’ll store for a few weeks in the fridge, but they also preserve well in canning and pickling recipes. Some cooks like to grind up dry florets and make flour from them or chop them into small pieces to create a rice-like dish; the possibilities are endless!

We’ll first discover when to chop down cauliflower for maximum harvests and then how to do it best.

When To Harvest Cauliflower

Close-up of a man's hands cutting compact white florets, surrounded by broad, deep green leaves, and placing them into a large wicker basket in a sunlit garden. — This vegetable thrives in cool weather before the summer heat.

Cauliflower is ready to harvest as its head reaches full size. How big this is depends on the variety; some kinds grow six inches long, and others reach up to ten inches! If you plan on harvesting during autumn, you most likely planted transplants into the garden from mid to late summer.

You can also grow cauliflower in early spring to harvest before midsummer. The goal with cauliflower is to have it reach full size before the hottest days of the year arrive. This vegetable suffers under intense heat, so you’ll want to time your harvest so it’s well before or well after midsummer.

Other unique varieties require long growing seasons of more than six months. These types are best for overwintering in mild climates, or they’ll need lots of time as seedlings indoors and ample time outdoors under full sun.

Most cauliflower varieties are ready 50 to 100 days after transplanting, and they’ll need four to six weeks indoors in pots. Time plantings so they occur under cool weather, and so they give your plants enough time to reach full size. Altogether, most types require 12 to 16 weeks to mature.

Apply Water and Fertilizer Regularly

The deep green leaves of the plant are broad and crinkled, adorned with glistening water droplets that cling to their surface. — Consistent care and moisture ensure robust, flavorful yields.

The key to a successful harvest is good care while your plants grow. Cauliflower is a tad fussier than other crops, and it may bolt if the plants struggle. Too much or too little water can cause bolting, and so can irregular fertilizing or insufficient nutrients.

This Brassica needs consistent moisture, especially during heat waves. Ensure the soil stays moist but not soggy, like a wrung-out sponge. If you garden with excessive clay or sand, add plenty of compost. It’ll help with drainage, promote beneficial microbes, and introduce hard-working worms.

Cauliflower likes ample nutrients before it matures. Apply one or two regular applications of organic vegetable fertilizer before heads start to form. If you forgot to fertilize, worry not; you can add a regular dose after the central florets start forming. Simply water it in well to ensure it doesn’t shock sensitive roots while they suck in nutrients.

Blanch The Heads

The plant features tightly packed, creamy white florets forming a dense head, surrounded by broad, lush green leaves that protect the developing curds from sunlight. — Blanching promotes vibrant white harvests.

As cauliflower swells and bulges, it may pop out of the foliage. Some varieties wrap their leaves around it naturally so the buds stay white and away from sunlight, while others need you to tie up the leaves for them. This blanching isn’t necessary but it promotes a healthy and bountiful harvest.

Blanch them by tying up the leaves around the heads with a soft material like rope or hemp string. Grab each leaf, bring it upward, and nestle it below the next leaf. You’ll form a rosette of folded leaves in a circle over the cauliflower. You’ll want them to block all sunlight from reaching inside, as it’ll cause discoloration and premature bolting. Peek on them every few days during this process and watch as they bulge into their final form!

Harvest Full-Size Cauliflower

Close-up of a woman's hands holding freshly picked, compact white florets arranged in a dense, spherical shape at the center. — Morning is the best time for cutting.

Cauliflower is ready for harvesting a few weeks after the blanching process. You’ll notice that they slow their swelling as temperatures reach freezing and days shorten in late fall. Cauliflower is frost-tolerant, but it dislikes reoccurring hard frosts.

The best time for harvesting is in the morning before the sun warms the soil. Slice them with pruners, leaving four to six inches of stem on them so they preserve well indoors. The stem keeps the rosettes sealed so no pests or diseases can attack them.

Dust off any dirt, bugs, or damaged parts that you see. You can untie the blanching leaves as you prepare to clean and store your crops. They may cause rotting during long-term storage if left on.

Once you chop off the main cauliflower head, there’s a chance your plant will continue growing smaller rosettes. Slice and eat small side shoots as they appear until hard frosts kill the plant. You may also chop down full-size plants after harvesting and compost them. This puts the nutrients they have locked up back into the soil so more plants can access them.

Lower Field Heat

A collection of tightly packed, snowy-white floret heads arranged in a wicker basket in the garden. — Dunk them in ice water to keep them crisp.

Fall temperatures are relatively cool depending on which zone you live in. Field heat is only a concern for gardeners with hot, sunny autumn days. The cauliflower soaks up the heat throughout the day, and its head can turn mushy once you chop it to store in your fridge.

Lower the effects of field heat by dunking your harvest in cold water immediately after harvesting them. Use ice-cold water for the best results—it shocks the plant, makes it crisp, and prevents rotting issues from excessive heat.

If it’s already cool in your area, you don’t have to dunk them. Simply clean and wash them, then prepare them for long-term storage.

Store Long Term

Several dome-shaped, crinkled white heads of cabbage displayed on a lattice shelf. — Ensure they are dry for optimal fridge storage.

Let your veggies dry fully before placing them in the crisper drawer of your refrigerator. Make sure they have no residual moisture on them, as it can cause rot or mushiness after a few days. Pat dry with a clean towel to remove all the water.

Clean, dry harvests last around seven to ten days in the refrigerator, although they can last longer in optimal conditions. Homegrown cauliflower is delicious, so it probably won’t last that long in your fridge! Keep it in a crisper drawer or sealed container to help it stay firm and fresh, and to prevent excess drying.

Popular Varieties

What varieties should you grow at home? That depends on your preferences, tastes, and garden conditions. Choose a type that thrives in your climate. Whether it’s mild or freezing during the winter, there are types for all gardeners in hardiness zones 2 through 11.

‘Romanesco’

‘Romanesco’ has a unique shape, and it’s lime green instead of white! This variety is an old European heirloom from the 1890s. It’s now a favorite of gardeners, chefs, and home cooks. This type appreciates cool weather and is better for a fall harvest than a spring one. This type doesn’t produce side shoots after harvesting, so you can compost the plant after you cut it.

‘Twister’

The compact, white florets have a frilly texture and are surrounded by ruffled, dark green leaves that add an ornamental touch. — This low-maintenance variety is perfect for beginner gardeners.

This self-blanching variety is perfect for the lazy gardener. It naturally wraps its large leaves around the forming heads and is low maintenance for beginner growers. ‘Twister’ resists heat, making it ideal for warm zones that other kinds bolt in.

‘Snowball Y’

The tightly packed, white florets form a dense, round head, encased in broad, vibrant green leaves with smooth edges. — This self-blanching variety produces delicious, large white florets.

Like ‘Twister,’ ‘Snowball Y’ is a self-blanching variety with leaves that naturally wrap the bulging heads. It’s a good keeping variety, as it holds onto mature florets well without bolting. Its heads are white, six inches long, and delicious!

Frequently Asked Questions

After bolting, cauliflower blossoms open up and pollinate each other. After pollination, seed pods form with ripe, black seeds. Pick them when they’re yellow or brown and crisp to the touch.

Cauliflower may produce side shoots after harvesting that you can slice and eat at will. Most varieties don’t do this, especially ‘Romanesco.’ You’ll have one main harvest if you grow a type without side shoots.

The best month for harvesting depends on when you planted your crops and how long they need to mature. Most varieties finish by September through November if you plant them in midsummer. Early spring plantings mature from March through May, depending on how late your last frost date is.