Cauliflower is a quintessential cool season vegetable to grow in your home garden. It may not have been your favorite veggie growing up, but you might find that growing your own is surprisingly enjoyable.

Cauliflower is one of those weird brassica crops that you grow for the edible flower head, though the frilly-edged leaves are also edible and taste a bit like kale. Let’s look at how to grow your own cauliflower from seed and end up with a nice, tight head at harvest time!

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THE BEST TYPES OF CAULIFLOWER TO GROW

One of the great things about growing your own cauliflower is you can try a fun purple cauliflower if you’re bored of white varieties from the grocery store. Here are some of my favorite cauliflower varieties:

• Purple Crush – This variety from a seed company known for quality seed produces such a beautiful purple veggie that’s rich in antioxidants thanks to its royal color.

• Twister – This heat-resistant type grows white cauliflower heads that self-blanch so you get a really pure white in the end.

• Fioretto 70 – This variety is perfect for warmer climates. Originating in Asia, this tropical cauliflower variety has been meticulously developed to thrive in some of the globe’s most scorching areas, making it an excellent choice for gardeners in the South.

If you’re shopping on your own for cauliflower seeds, look for assurances that the outer wrapper leaves will shield the head from sun discoloration, a common issue with older varieties.

WHEN TO GROW CAULIFLOWER

Cauliflower, like other cole crops, loves cool temperatures. It needs cool air and cool soil to germinate. Once it’s growing, it thrives in temps below 75 degrees Fahrenheit.

The best time to grow cauliflower is during the cool weather of spring and fall. If you live in a warmer climate like me down here in Central Texas, the opportunities to grow this cool-season crop are blink-and-you-miss-them short, which means it’s super important to start seeds indoors or buy transplants to get a head start on the growing season.

If you’re planting in the spring, count back 4 to 6 weeks from your last frost date. This is when you can start seeds for cauliflower indoors under a grow light. For those of us in warmer climates, this could be as early as January.

For fall planting, you’ll count back 12 weeks before your average first frost date to determine when to start seeds indoors for a late fall or winter harvest.

Gardeners in warmer climates should use shade cloth to give their young plants some protection from the heat while they’re getting settled in the garden.

I know here in the greater Austin area it can still be in the 90s in September, when it’s time for us to do our fall planting of cauliflower.

WHERE TO GROW CAULIFLOWER

Because it’s a fairly large plant, I like to grow cauliflower in my raised garden beds. The raised bed should provide the nutrient-rich soil and good drainage that will keep these veggies happy.

Make sure to pick a spot that receives full sun, or at least 6 hours of direct sunlight each day. These plants need lots of energy to form large heads. If, however, you’re expecting warmer temperatures, you might want to provide some afternoon shade.

HOW TO GERMINATE CAULIFLOWER SEEDS

Unless you have a good three months of nice, cool weather, it’s best to start cauliflower seeds indoors ahead of time so that you can move seedlings outdoors as soon as the temps are right. If you’re new to seed starting indoors, make sure to check out our guide to ensure success.

You’ll need a seed starting tray, an organic seed starting mix or a light potting mix like this one from FoxFarm, and a set of grow lights. Since cauliflower seeds germinate best in cooler temperatures, you’ll forego the warming mat.

Steps to start cauliflower indoors

1. Hydrate your seed starting mix or potting soil with water and fill your seed starting tray to the top.

2. Use a chopstick or pencil tip to press a little hole into the mix in each cell. Sow each cauliflower seed about 1/4″ deep and cover with seed starting mix or moist potting soil. Plant only one seed per cell to avoid the need to thin seedlings later.

3. Keep the soil moist until the seeds sprout by covering them with a plastic dome, burlap, or plastic wrap. Uncover once they start sprouting, which typically occurs in about 8 to 10 days. Water the seeds from the bottom if possible.

4. Once seeds have sprouted, turn on grow lights for at least 12 hours a day and keep them about 2″ above seedlings.

5. When the cauliflower seedlings have their first set of true leaves, you can add some diluted seaweed extract to give them essential nutrients every 2 to 4 weeks. Aim a small fan on the lowest setting to ensure good air circulation around seedlings and to get them used to wind.

HOW TO PLANT CAULIFLOWER SEEDLINGS

If you started cauliflower seedlings indoors, it’s best to “harden them off” before planting them outside. That means leaving the trays outdoors for longer increments each day to get seedlings used to outside temperatures, sunlight, and wind in order to reduce transplant shock. Hardening off is best done over a 7-day period.

You always have the option to buy healthy cauliflower plant starts from a local nursery if starting your own seeds sounds overwhelming or proves unsuccessful. This is still a great way to get a head start on your growing season. 

Steps to transplant cauliflower plants

1. Add some compost to the top of the planting area. 

2. Plant seedings about 12″-18″ apart. Dig a hole that’s a little deeper than the root ball of the plant and plant each cauliflower all the way up to the first set of leaves to give them some support. 

3. Water the plants in well. Keep the soil evenly moist. 

HOW TO CARE FOR GROWING CAULIFLOWER PLANTS

Tending tasks for cauliflower include feeding, protecting from weather, watering, and checking for pests.

Fertilizing cauliflower plants

Cauliflower is fairly easy to tend in the garden, though it is what we call a heavy feeder, meaning it needs to be fertilized often. I try to use only natural products to feed my plants and avoid synthetic fertilizer.

Here’s my recommended three-part fertilizing regimen to keep these plants happy and healthy while they’re forming their flower head:

Phase One

Add a 1- to 2-inch layer of compost to the top of your soil before you sow cauliflower seeds or transplant seedlings to your garden. This gives young plants a little nutritional boost at the time of planting. Compost also helps to hold moisture in the soil, which is important for good cauliflower seed germination. If you want, you can also add blood meal or chicken manure, if you’ve got it, to the top of your soil to further boost available nutrition.

Phase Two

As your cauliflower plants are getting settled in your garden, you can begin feeding them a nitrogen-rich diet to encourage lots of green growth. I like MicroLife Ocean Harvest, an organic liquid fertilizer. Mix according to the directions on the bottle and apply it as you water your plants. Repeat every 2 weeks.

Phase Three

Cauliflower heads are actually clusters of closed flower buds harvested before blooming. As soon as you see your cauliflower plants begin to form a central flower head, you’ll want to stop giving them nitrogen. You don’t need the plants to grow more leaves; you want them focused on forming nice, large heads by giving them a fertilizer that promotes flowering. I like MicroLife Maximum Blooms, another liquid fertilizer that can be applied every 2 weeks.

Protecting cauliflower plants from extreme temps

Cauliflower plants often need to be protected from the weather near the beginning and end of their growing season.

Most cauliflower types have low heat tolerance, so protecting the developing head before a warm spell is particularly important to prevent something called “buttoning”, or producing a smaller head than expected. Shade cloth is the best way to keep plants cool right after planting in late summer or early fall or before harvesting in late spring. Shade cloth still lets in sunlight but keeps the surrounding air and soil underneath cooler.

Similarly, cauliflower might need to be protected from frost near the beginning of its life in early spring or right before harvest in late fall or early winter. Cauliflower can typically handle temps as low as 26 degrees Fahrenheit without damage, but it’s still a good idea to cover them with some old sheets, frost cloth, or a row cover if you’re expecting a freeze.

Watering cauliflower plants

Water is essential for cauliflower to develop that nice mature head. These plants need at least 1 inch of water a week. If you’re not getting that much rain per week, supplement with a nice, deep soak from the garden hose, or a Growoya or set up some simple drip irrigation lines. Make sure to aim your water at the roots of the plant instead of the leaves if you’re watering by hand. While some plants like soil to dry out a bit, you can keep the soil evenly moist for cauliflower.

Preventing pests on cauliflower plants

HOW TO HARVEST CAULIFLOWER

Harvest mature heads before the flowers open. (If you miss your window and notice flowers appearing, don’t worry—the head is still 100% edible.) Each floret will be about as long as your thumb.

To harvest your cauliflower head, use a clean knife to cut at the base, just below the head. While broccoli plants can be left in the garden in anticipation of more small heads, cauliflower only ever produces one main head, unfortunately. Compost the base of the plant if you haven’t had major pest issues.

It’s best to harvest during the cool morning hours and refrigerate as soon as possible. Cauliflower heads can be stored in the refrigerator for 3 to 5 days. Blanched cauliflower freezes well and maintains its quality for up to 12 months.

Lettuce Help You Grow

I hope these tips help you grow the yummiest cauliflower head ever! If you still need a garden space installed or if you’re looking to improve on your current setup, we’d be happy to design your garden, come do a garden check in, or give you one-on-one advice in person or over Zoom.

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