white cauliflower head shown close up with green leaves in the background

Problems With Growing Cauliflower: the correct method of growing

Mark Twain once said that cauliflower is nothing but cabbage with a college education! Thankfully, a college education is not required for growing your own cauliflower at home, but are you aware of problems with growing cauliflower?

This cool weather plant can even yield 2 harvests per growing season outdoors if you plan carefully. It is a descendant of the wild cabbage plant, and contains plenty of antioxidants, fibre, vitamins, and even cancer-fighting compounds called glucosinolates. Recent research also shows a link between white-fleshed vegetables and a reduced risk of stroke.

Though growing cauliflower is fairly easy, it does require a fair bit of skill and dedication to produce the best yield. We’ll cover all you need to know about planting, growing, harvesting, and storing this super-vegetable at home.

Planting cauliflower

Choosing your cauliflower variety

In general, cauliflower is no more difficult to grow than any other garden vegetable or tomato plant. The ‘Snowball’ provides a good yield with medium-sized heads, though other varietals, such as ‘Romanesco’ – a green variety, ‘Violet Queen’, or ‘Cheddar’ – which is an orange cauliflower than contains more vitamin A – have a similar taste, and are also easy to grow.

Seeds, shoots, or scraps?

Like other cruciferous vegetables, cauliflower can be grown from seeds, shoots, or scraps. They can be grown outdoors in a planting bed, or in a container, even indoors if the conditions are right.

Growing from a seed will take longer, and growing from food scraps may produce a bunch of smaller heads rather than one large one. Cauliflower starts (or shoots) can be purchased at most garden centres and will usually provide a good balance between a speedy harvest and a solid yield.

When to plant cauliflower

As cauliflower prefers cooler temperatures and slight humidity, it will grow during the spring, summer or fall. A crop planted in mid-spring will take 8-10 weeks to grow, producing a mid-summer harvest. If planted in mid-summer, the cauliflower will need only 4-5 weeks to produce a crop. Fall crops tend to produce higher-quality plants than summer crops.

If you’re beginning from seeds, start your spring crop indoors (in the house or greenhouse) approximately 10 weeks before the last average frost date for your area.

I always advise to sow seeds in a germination station to get them started. These are inexpensive and the provide the best environment to get your seedlings started.

Be sure to leave 12 weeks before your area’s first frost date for your fall crop to mature. If you have a seed germinating box, it would be best to start them off there.

If you’re uncertain of the best timing in your climate, you may want to start a new batch weekly for a 4-6 weeks period to see which works out best.

Seed spacing

It’s best to check the seed packet for the producer’s recommendations for depth and spacing, but generally cauliflower should be planted ½” to ¾” deep in rows that are between 3 and 6 inches apart, and no more than 8 seeds per foot in each row.

Growing cauliflower

Moving the starts outdoors

When the seedlings have reached at least 2” tall and each have 3-4 leaves, the plants are ready to move outdoors – provided that the weather is appropriate.Choose a planting site that will be in full sun for at least 6 hours per day, where the cauliflower will not be shaded by taller plants. The starts can be transplanted into rows that are 8”-10” wide, with at least 36” between the rows and 18”-24” between the plants. For the first watering, include a high phosphate fertilizer to help the plants establish themselves in the soil.

In the garden

Cauliflower prefer a moist soil – slightly less than 2” of water weekly – so be sure to water consistently during the summer, when the weather is more likely to be hot and dry. Paradoxically, they are also sensitive to overwatering, so every 5-7 days is usually sufficient for areas with regular, light rains. Ensure that your planting bed has good drainage so that excess water does not accumulate.

It’s best to fertilize your plants frequently as cauliflower requires plenty of potassium and nitrogen for healthy development. Also, maintain a pH level between 6.5 and 7 – if the soil is too acidic, the cauliflower will show symptoms of magnesium deficiency, with smaller heads and paler leaves.

Problems with growing cauliflower

Young, fragile cauliflower plants are vulnerable to a number of garden pests such as aphids or cabbage worms. Some pests could completely ruin a cauliflower crop, so use either a plant-friendly pesticide or nontoxic pest treatment at the first sign of trouble.

Another problem with growing cauliflower (and its cousins in the Brassica family) they prone to a fungal infection called clubroot that causes growths on the plant roots.

This interferes with the plant’s ability to absorb water and nutrients. This fungus is highly contagious, and any affected plants should be pulled up immediately by the roots and discarded. Do not compost them!

Another common fungus causes blackleg – irregular grey patches or lesions on the leaves. As this fungus is difficult to treat, the best technique is preventative treatment such as crop rotation or washing seeds in hot water to remove the fungus before planting them.

Harvesting cauliflower

When to harvest

Whether it’s the spring/summer or summer/autumn planting, when the recommended growth time has elapsed, it’s time to begin watching the plants for signs of readiness.

Before the harvest

The harvest process for Cauliflower is a long one; first, if you’ve chosen a white varietal, when the curd (the head of the plant) is 2”-3” in diameter, the outer leaves should be loosely tied over the head.

This process is called blanching and will protect the head from the sun, allowing it to maintain a beautiful white color. The leaves can be tied within elastic bands, twine, or even tape – ensure that the head is dry before blanching, and that air can circulate freely between the tied leaves and the cauliflower head.

How to harvest

Usually, 7-12 days after blanching, the cauliflower will be ready to harvest. The head should be firm and compact – ideally, it will be 8”-9” in diameter.

Using a large – a very sharp – knife, cut the head off the plant. Be sure to leave some leaves around the head to protect it.

Storing cauliflower

Where should cauliflower be stored?

A head of cauliflower should be kept cool – it can be placed in a sealed plastic bag in the refrigerator.

How long will it last?

The refrigerated cauliflower will last about a week; so long that is has not turned brown, it’s good to eat.

Can cauliflower be preserved?

Cauliflower heads can either be frozen or pickled for long-term storage.

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