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Why Is My Cauliflower Purple? 4 Main Causes & Solutions

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Cauliflower is a very healthy root vegetable that belongs to the Brassica family. Their head is a cluster of pure white or light cream flowers.

However, there are times when you will find that the cauliflower is not entirely white as expected, instead of appearing a little purple on the Cauliflower. So, if you’re wondering, “Why is my cauliflower purple?” Then the following article will help you answer your question.

Why Is My Cauliflower Purple
Anyone know what’s up with my cauliflower – via Reddit

Why Is My Cauliflower Purple?

1. Variety of Cauliflower

The real reason your cauliflower has purple heads may be because you accidentally bought purple cauliflower seeds. This type of cauliflower has the same taste as white cauliflower, just different in color. 

Therefore, you can double-check the labeling on your seedlings or seed packets to see if you’ve made a mistake.

Why Is My Cauliflower Purple 2
The rare purple cauliflower – via Reddit

2. Fungal Disease

One of the leading causes of your cauliflower turning purple is a fungal disease. Although cauliflower is less susceptible to ringworm than cabbage, it is highly vulnerable to fungal infections.

When cauliflower is infected with this disease, the identifying feature is brown spots on the body and dark purple edges or black legs. To prevent the spread of fungal diseases in cauliflower, it is essential to remove infected seedlings immediately.

Also, learn for years to come, so you don’t plant cauliflower where other cruciferous crops have been grown, such as broccoli and cabbage.

3. Sun Exposure

If you purchased the right cauliflower seeds, but the plants grow with purple tips, chances are they have been exposed to sun damage without protection.

Cauliflower usually grows very well in full sun but only when grown during the cooler months. During the peak of summer, intense heat can increase the pigmentation of cauliflower, especially at the top of the plant. From there, the curds can turn purple.

To protect the cauliflower from keeping its creamy white color, you can apply a method known as blanching. In addition, you can cover the top of the cauliflower to protect them from direct sunlight.

Usually, the plant’s leaves are large enough to cover the cauliflower, and you can secure them using clothespins or twine. Alternatively, you can tie them tightly around their heads with a paper bag to keep the cauliflower from retaining its creamy white color.

4. Soil Nutrients

Cauliflower usually grows well in soils rich in potassium and nitrogen. However, growing in an environment with too much nitrogen can lead to discoloration. The head develops too early when the leaves are not large enough to cover the curd and protect them from direct sunlight.

Besides, phosphorus-deficient soil is also the cause of purple color in cauliflower. Therefore, you need to ensure the right level of nutrients when growing cauliflower to produce the best yield.

Is Purple Cauliflower Edible?

Curds are inherently creamy white, but you need to double-check them before cooking them when it appears tinted. If the cauliflower turns purple, but there are no signs of pests or diseases, you can harvest and enjoy them.

However, if they appear to be disease-like, especially if they have a foul odor or are mushy consistency, then it’s best to get rid of them.

Finally, if the curds have parts that have been burned by the sun, you can cut out the damaged parts and use the unblemished parts. The purple parts from being exposed to heat will probably become more bitter than usual, but you won’t feel this difference if it’s not really subtle.

How To Prevent Cauliflowers From Turning Purple

To avoid discoloration in your cauliflower, prepare a self-blanching variety that has been developed to protect the curd well, or blanch or cover the head while it is growing.

To blanch the cauliflower, when the curd is 2 inches across, you need to cover it with leaves around it and secure them with clips or garden wire. This shielding will help the curd avoid direct sunlight exposure and maintain its original creamy white color.

The best time to plant cauliflower is in the cooler months, like September or October. However, if you grow in the months when the temperature is high, it is easy to make the head of the cauliflower purple, or even the appearance of leaves sprouting from the curd.

You can grow two crops a year in most regions, planting the fall crop after the spring harvest. After seeding, it will take about two weeks to germinate and sprout, so keep this time in your schedule when you want to plant cauliflower.

In addition, you can also grow cauliflower indoors, provided the soil has enough moisture and plenty of nutrients. You need to regularly provide the necessary nutrients by applying decayed manure or compost.

Also, be sure to add nitrogen, phosphorus, or potassium to the soil when transplanting and while the plants are growing.

Besides, it would help if you made sure the ideal PH of the soil is between 6.0 and 7.0. If the soil is acidic, it is necessary to add a little lime to increase the pH, which will help prevent root rot or fungal diseases that are harmful to the roots.

This plant needs daytime temperatures between 70-85 F. (21-29 C.), but an early enough start time for planting will help the curd grow large.

However, if you plant too early, the young cauliflowers may experience late-season frosts that cause them to wilt. Therefore, you can choose to buy early ripening or late-ripening varieties, depending on the climate in your area.

Final Thought

So we have just helped you answer the question “Why is my cauliflower purple” by giving the leading causes and ways to avoid this situation when growing cauliflower. You can enjoy purple cauliflower, although it tastes a bit different.

Besides, you must make a good plan like what we have instructed to have the best crop. We hope that the knowledge we share will be helpful to you. Finally, don’t forget to revisit us for more great gardening tips.