Rows of growing cauliflower plants are a common sight in vegetable gardens. One of the most versatile members of the brassica family, cauliflower is happiest in compact rows in cool climates. Their edible, neat head, in white as well as shades of purple and orange, are a common sight in vegetable gardens.
Happiest in cooler climates, the cauliflower (Brassica oleracea) has an unfair reputation for being difficult to grow. However with a little care and attention, and the help of this guide, you will be able to cultivate your own crop of great tasting cauliflower.
Varieties of Cauliflower
The most important step in growing cauliflower is identifying a variety that will be able to mature in your climate. Cauliflower head won’t form in warm weather. They will also only tolerate a light frost. In particularly cold climates try growing cauliflower plants undercover.
White Cauliflower is a familiar sight in vegetable gardens. Despite their reputation this is an easy to cultivate, beneficial crop.
Gardeners who enjoy a short spring or fall should select fast maturing varieties. If you enjoy a mild or late winter you will be able to grow a slow maturing variety. Gardeners in USDA zones 5 and lower should try starting seed undercover before planting out in mid or late summer. This will allow you to enjoy a fall harvest.
Cauliflower (Brassica oleracea) plants have specific needs. Gardeners in warmer climates will need to grow fast maturing varieties. This may seem restrictive but there is still plenty of choice on offer.
Requirements to grow cauliflower may seem to restrict your choices somewhat. However you will find, especially if you are grow cauliflower from seed, that there are still plenty of varieties to choose from. Some of the most reliable varieties of are:
Snowball produces medium sized head, providing a continuous, reliable yield throughout the growing season.
Romanesco Early is an easy to grow, attractive variety. It produces lime green, crisp florets that can be harvested throughout the growing season.
Cheddar F1 is a slow to bolt variety that produces attractive, orange head.
Di Sicilia Violetta is a stunning purple heirloom variety. It produces head with a distinctive nutty and sweet flavor.
Snow Crown F1 is a quick growing hybrid variety that has some frost tolerance. It is an ideal choice for gardeners with only a short growing season.
While the traditional white cauliflower is still commonly grown, other varieties are gaining in popularity. Coming in different colors, or shapes such as Romanesco, they can add interest and variety to a vegetable garden.
Tips for Growing Cauliflower
If you plan to grow cauliflower crops every year you should implement a simple crop rotation system. This applies if you are growing in the ground or in raised beds.
If you grow cauliflower plants every year, a crop rotation system should be implemented. This will ensure the plants are always growing in healthy soil. It will also reduce the chances of disease striking.
Where and When to Plant
Cauliflower plants like cool temperatures and moist atmospheres. An average temperature range between 65-70℉. Prolonged exposure to warmer temperatures will trigger bolting. Gardeners in warmer climates can avoid bolting by growing quick maturing varieties or by growing in partial shade.
Cauliflower likes partial shade. However they do best in full sun positions, receiving 6 hours of sunlight every day.
Sow cauliflower seeds outside from early March until May. If you want to sow earlier, sow undercover from January onwards. However you will need to be careful. Cauliflower plants dislike having their roots disturbed. If this happens during transplanting the plants may fail.
Gardeners in milder climates can sow cauliflower in the fall and harvest cauliflower in early spring.
The range and variety of cauliflower on offer means that you will be able to find at least one variety that is suitable for your situation.
Sowing Cauliflower Indoors
As I have already mentioned cauliflower plants dislike having their roots disturbed. If you want to sow undercover and transplant the seedlings outside later then you will need to be careful. Sowing the seeds into peat or paper pots will allow you to transplant the seedlings still in their pots. This means that the roots won’t be disturbed. As the plants grow, the pot will decompose.
Sow two cauliflower seeds into each pot. Sowing two means that if one seed fails, the other should germinate. If both germinate remove the weaker seedling.
Sowing seeds thinly can be difficult. Instead thin the seeds out once they have germinated. This also helps you to ensure that the plants have enough space to grow properly.
Sow to a depth of about half an inch. Cover with a thin layer of fresh, general purpose compost. Water with a gentle spray.
Cauliflower seeds germinate at 70℉. A south facing windowsill or in a greenhouse should be warm enough. In colder climates you will need to place the seeds into a propagator to start germination. Don’t let the pots dry out.
Germination will take 2 weeks. Within 6 weeks the seedlings will be ready to transplant.
Sowing Cauliflower Seeds Outside
Cauliflower plants do best in well draining soil. Working the soil with a fork before planting will break up clumps of earth and improve the drainage. Working in organic matter or general purpose fertilizer before planting also helps to improve the soil.
Compost is a great way of returning nutrients to the soil. As well as amending the soil compost can also be applied as an organic mulch, adding nutrients to the soil and improving moisture retention. Having your own compost heap also helps to reduce garden and kitchen waster.
Scatter the seeds in lines and cover with a thin layer of soil. As the seedlings grow they will need to be thinned out. How much space cauliflower requires depends on the variety, so check the instructions on the seed packet. In general small cauliflower will require spacing to 6 inches, larger varieties will need up to 24 inches.
After sowing the seeds, water with a gentle spray. Anything stronger may wash the seeds away.
How to Transplant Cauliflower Seedlings
Harden off cauliflower seedlings before transplanting.
Water the seedlings well an hour before transplanting. This prevents the plant from producing deformed or small head.
Cauliflower dislikes having their roots disturbed. Sowing seeds in paper pots allows you to plant the seedling and the pot in the ground without the need to disturb the root system. The pot will the decompose as the cauliflower grows.
Place each seedling in a hole about half an inch deep. The lower leaves of the plant should just brush the ground. Space the growing cauliflower out so that the outer leaves have enough room to form. The exact spacing will vary depending on the variety, so check the seed packet.
After planting, water in well.
Cauliflower Care Guide
Once planted cauliflower plants are relatively easy to care for. Regularly weed around your the plants. Young plants can often be overwhelmed by fast growing weeds. They can also deprive plants of valuable nutrients and water.
Once planted keep the area around the cauliflower weed free. Regularly water and feed your crop to ensure healthy growth.
Watering and Fertilizing
Water cauliflower regularly. They should not be allowed to dry out.
Placing a layer of organic mulch, such as compost, around the plants will help the soil to retain moisture. It will also provide extra nutrients, encouraging healthy growth.
Once established, apply a high nitrogen feed. An organic fertilizer such as kelp or fish emulsion can also be applied. This will encourage growth. Homemade fertilizers are a great way of feeding your plants without using potentially harmful chemicals.
Blanching Cauliflower Plants
Learning how to blanch correctly is a vital part of growing cauliflower.
The white cauliflower needs to be blanched otherwise they will turn a yellow-brown color. This is the plants natural shade but can look unappealing. Unblanched cauliflower is still edible.
When the head of the cauliflower reaches the size of a large egg you will need to begin blanching the plant. Blanching prevents light from reaching the cauliflower head. This is necessary if you want the Cauliflower head to remain a bright white color when you harvest Cauliflower.
Colored varieties of cauliflower do not need to be blanched pre harvest.
When the head of the cauliflower reaches the size of a large egg, stop watering in preparation for harvest. This will prevent the plant from rotting. Fold some of the larger leaves over the head of the cauliflower. This will prevent light from reaching the head. You can secure the leaves in place with string but don’t tie it too tightly. The leaves should still have room to grow.
An easier method is to cover the cauliflower with an upturned bucket.
Once the head is covered water only the soil around the cauliflower. Don’t water the leaves. Check the undersides of the leaves for harmful pests every day.
You can harvest Cauliflower 12 days after blanching.
Cauliflower is part of the brassica family. This means they are susceptible to a couple of common pests. Cabbage root fly maggots will quickly destroy root systems. This stunts growth and eventually kills the plant. Cabbage white caterpillars will reduce healthy plants to skeletons within a few days. To prevent these pests, regularly check the underside of leaves for yellow eggs. If you find any, brush or wash them away. Covering the cauliflowers with a fine net, cloche, or fleece will also protect them.
Cauliflowers can fall victim to a number of pests and diseases. Covering the crops with netting prevents most pests from accessing the plants.
Cabbage whitefly is a less destructive pest. It will cover the leaves with a sticky substance known as honeydew. This will then turn into a grey mould. Wash away whitefly infestations with a strong jet of water. Cut away any yellowing leaves.
Groundhogs and pigeons can also target plants. Pigeons in particular will pull up row after row of young seedlings. Covering your crops with a cage or net will deter most large pests.
Leaf tip dieback, or distortion, is a common problem. It is usually caused by a lack of boron. Applying kelp or seaweed fertilizer to the soil will help to cure the issue.
Clubroot is a far more destructive disease. It can stunt plants, causing the leaves to turn a red-purple color before wilting. On lifting damaged plants you will observe swollen or deformed roots. They may also give off a foul odor. As the disease advances the root will collapse into a slimy pulp.
Should clubroot strike you will need to pull up the affected crop and burn it. Don’t place the affected plants on the compost heap.
Clubroot survives in the soil for up to 9 years. You won’t be able to grow brassicas in the soil for this length of time. Liming the soil every fall helps to deter clubroot. Liming helps to make the soil neutral or slightly alkaline. Clubroot prefers acidic conditions. Crop rotation and growing in raised beds or containers can also deter clubroot.
Many vegetable gardeners like to practice companion planting. This is the practice of planting mutually beneficial plants together. This can help to improve plant health and yield. Many plants benefit from being grown close to cauliflowers. Cauliflower in turn benefits from rich soil that is rich with nutrients and also filled with nitrogen.
Cauliflower, beans and celery is a popular combination. Beans and cauliflower both attract beneficial insects and deter pests. Meanwhile celery will add nutrients beneficial to the soil. However in return the celery will take up a lot of moisture.
Other good companion plants are:
- Brussels Sprouts
Planting aromatic herbs such as thyme and sage will help to deter pests while attracting bees and beneficial insects.
Plants to Avoid
Peas and tomatoes will both stunt cauliflower growth. Strawberries should also be avoided. They tend to attract slugs that will quickly destroy your plants if left unprotected.
How to Harvest and Store Cauliflower
Harvest cauliflower when the head is 6-8 inches in diameter. The buds should be tightly packed together. Small heads that start to open should also be harvested.
If left in the ground too long cauliflower will appear coarse. Overly mature cauliflower lacks a pleasant flavor and are best discarded.
Harvest cauliflower by cutting the head, and some of the leaves, away from the plant with a sharp knife.
Cauliflower should be harvested when the head has reached the desired size and the buds are still tightly compacted. As the buds separate the crop begins to lose its flavor.
Leave the main stem of the plant in the ground. Cauliflower continues to produce small, edible florets, similar to broccoli, after the initial harvest.
Cauliflower can be kept in a paper bag in the refrigerator for up to a week. If you need to store the crop for longer it can be frozen or pickled.
Colorful and easy to grow, cauliflowers are a popular part of the vegetable garden. If cared for correctly you will be able to enjoy homegrown cauliflowers throughout the season.
Growing cauliflower is often considered to be a difficult task. However this staple of the vegetable garden is, once established, an easy plant to cultivate. A beneficiary of crop rotation if cared for correctly, you will be able to enjoy cauliflower in your own garden with little trouble.
Elizabeth learnt to love gardening as a child in her grandparents backyard. Today, she is a trained horticulturist and has maintained a productive allotment for over 10 years. When not growing her own, Elizabeth enjoys helping other people with the plant problems. An experienced writer and editor, away from gardening Elizabeth is also a keen bird watcher, local historian and genealogist, meaning that she can often be found with her dogs exploring an overgrown graveyard.