Cauliflower may be a bit more challenging to grow than other garden vegetables, such as kale and chard, but with these few simple steps you'll be able to grow this hearty vegetable, which is high in fiber, vitamin C and a good source of several other nutrients.
Cauliflower likes to grow in full sun and rich, moist, well-drained soil with a pH between 6 and 7. Till the soil to loosen it to a depth of 12-15 inches. Then, work in a 3-inch layer of nutrient-rich compost or garden soil, such as Miracle-Gro® Organic Choice® Garden Soil, into the top 6 inches of native soil.
If you're start cauliflower seeds indoors, wait until seedlings have 5 leaves before transplanting them to your garden (this will take about 4-6 weeks). Also, make sure to harden off your seedlings before planting, gradually adjusting them to outdoor conditions by leaving them outside for a few hours a day. Move them permanently outdoors two weeks before your last frost date, and place each seedling 24 inches apart. If you're starting outdoors, sow cauliflower seeds 1/2 inch deep and 24 inches apart in rows 3 feet apart.
Water as necessary to keep the soil consistently moist and add a 3-inch layer of mulch to help retain moisture and keep soil temperatures cooler.
If your cauliflower variety has white heads, you'll want to ensure a bright white head by covering it as it grows. This is called blanching. When the head reaches about the size of an egg, pull the longest leaves up and over it, then secure them in place with twine or an elastic band. Purple, green and orange cauliflower heads don't need to be blanched.
Your cauliflower will be ready harvest when the heads are 6-8 inches in diameter, roughly 10 days after blanching. Harvest by cutting the stalk just below the head, leaving a stem of about 1-2 inches.