Cauliflower is the most demanding of the Cole crop family. It’s best suited to cool, humid growing conditions and needs to keep growing without any hitches, such as a water shortage, or it will produce premature undersized heads. Make sure to blanch the cauliflower leaves or chose a self-blanching variety if you want a snowy white head. This crop also takes up a lot of space for how much it yields, so think about space considerations before planting. Also, most commercial growers start this crop in August to have beautiful, white flowers ready for harvest in late October through November. 75% of all cauliflower is sold during the holiday season.
SOIL PREPARATION
Cauliflower prefers a sandy, soil rich in organic matter, well drained, and not too heavy. They also need full sun exposure. Before planting, incorporate 2-3 inches of well composted organic matter and 1-2 lbs of all-purpose fertilizer (we recommend “That’s All it Takes” complete fertilizer) per 100 square feet and work them into the soil to a depth of 4-6 inches. Heavy, clay-based soils must be amended with compost and organic matter to encourage and allow good root development. If you have clay soils we recommend 4-6 inches of organic matter and 50 lbs of Utelite or Zeolite per 200 square feet added to the soil each fall for multiple years to increase drainage and nutrient availability. Over time, you can create a better growing environment for your garden plants to thrive in and produce. Please see our information sheet “Preparing your Soil” for more detailed info on soil preparation before planting.
VARIETIES
Anderson’s has two great cauliflower varieties: Early Snowball, which is a popular variety for market and freezing. And Stardust, which is a self blanching, high yielding variety. If you don’t like the extra work of blanching the flowerettes (see blanching info below), you definitely want to grow Stardust, as it requires less work to keep the flower white.
PLANTING
Like other Cole crops, cauliflower tends to bolt when temperatures are high so plant in cool weather (March & April). Young plants can resist a light frost but not a hard freeze, but don’t wait until May. Heat can stunt the early development of your crop. When planting starts, place plants 3 feet apart in the row, with 4 feet between rows. Planting into plastic or fabric mulches will accelerate early growth and encourage higher yields as well as suppress weed development. For best results, water immediately after transplanting with Kangaroots rooting solution and again for the first 2-3 waterings. This will prevent transplant shock and give your transplants the best possible opportunity to thrive. When planting seed, plant 2 seeds every 36” and about ¼ - ¾ inch deep, and thin the sprouts when plants have 3-4 true leaves.
WATER
Water cauliflower deeply and infrequently while trying to maintain even soil moisture. Cauliflower needs consistent watering for high quality and quantity production. Water stress during growth and bud production will result in premature flowering, bitter taste, and poor quality. Use a soaker hose for uniform water distribution and water lightly every 5-7 days to maintain soil moisture during these essential growth stages. A light compost mulch can help as well if daytime temperatures start to climb over 80 degrees. Moisture is essential, but too much water can result in root rot diseases and slow plant growth.
FERTILIZER
Apply ½ cup per 10 feet of row of “That’s All it Takes” complete fertilizer or Happy Frog Organic Tomato & Vegetable Food 4 weeks after transplanting or thinning to encourage vigorous plant growth. Apply an additional ¼ cup of nitrogen-based fertilizer when the cauliflower head is the size of a quarter. Fertilize again after main head is harvested to encourage side shoot growth. Place the fertilizer 6 inches to the side of the plant and work it lightly into the soil before watering. Make sure to water it in! We also recommend treating your cauliflower seed or plants with beneficial microbes and mycorrhizae (Kangaroots or Myke). These added helpers bring nutrients and water directly to the plants that host them, making them stronger, more resistant to insects and diseases, and more drought tolerant.
COMMON PROBLEMS
Keep the weeds to a minimum with the use of plastic and organic mulches. We prefer the Pro 5 weed barrier as it allows water and nutrient to pass through, but stops even the most difficult weeds as they germinate. Treflan and Corn Gluten weed preventative herbicides are also very effective ways to stop weeds before they start, saving you hours and hours of weeding. Be sure to control weeds when they are small to ensure damage is not done to cauliflower root systems when weeds are removed. Practice crop rotations to discourage pest problems. Cauliflower is subject to aphids, cabbage loopers, imported cabbage worms, and cabbage root maggots. Row covers will help protect plants from all of these pests. All of the caterpillars may also be controlled using Bacillus thuringiensis (B.T.), spinosad, or pyrethrin. We prefer to spray Spinosad (since it is bacterial, it has no effect on people or pets) early or late in the day for best caterpillar control. Aphids can be controlled with an insecticide like Ferti-lome Broad Spectrum Insecticide or Ferti-lome organic Triple Action.
HARVESTING:
As the head enlarges, it will discolor and develop a bitter flavor if exposed to sun. Blanch the head by tying the leaves together with strong twine or rubber bands when the heads are the size of silver dollars. Harvest the heads when they are fully developed (6-12 inches in diameter), compact, and blanched white. A large knife or a lopper pruner both work well for cutting the flowers from the plants. Cauliflower can be stored for 3 weeks in a cool, dark, dry place, or blanched and frozen for long term storage.