Pests and Diseases that Affect Cauliflower

Like all crops, cauliflowers have its own set of insects or pests that appreciate its taste.  There are diseases, too, that commonly affect cauliflowers.

What are some of these pests and diseases you should watch out for?  How would you know when they are already affecting your crops?  What should you do in case your plants get attacked?

Root Rot

Ever notice the leaves of your cauliflower plant begin to turn yellow?  It could be that your crop has root rot, a disease which most cauliflowers are vulnerable to.

The best way to avoid this is to grow cauliflower varieties that are root rot-resistant and avoid handling wet plants.  But should you notice some of your cauliflowers begin to show signs of this disease, immediately remove them to keep the rest from being affected.

Alternaria Leaf Spot

If you see brown spots on the lower leaves of your plant, which turns yellow after a while before completely dropping off, it might be affected by a fungal disease called Alternaria leaf spot.

To control this disease you can use hot water and chemical seed treatments.  Fungicidal application will also prevent the disease to become worse.  Make sure to avoid overhead irrigation and to plant in areas where no member of the cruciferous vegetable has grown the past three years.


You would recognize if your crop is affected by clubroot when your cauliflowers begin to wilt during hot days.  They also would develop stunted red tops

Once you lift the plant, you would notice a swelling in its roots like a club.  In cases where the infestation is bad, the roots would even give out a horrible stench.

Clubroot is caused by a virulent fungus that persists in the soil for many years as its spores can lay dormant for as long as 20 years.  It spreads on footwear, through the soil water and garden tools.

How does one get rid of this devastating disease?

Sadly, there is no known cure for clubroot.  However, you can follow strategies to soften its impact and still produce decent crops.

You can start by raising the acidity level of the soil to around 7pH, make raised beds for improved drainage and add well-rotted manure and organic matter to the soil.  You may also contact your local county extension office for recommendations on how to control this disease.

Cabbage Root Maggot

Cabbage root maggot feeds on cauliflower stems and roots and may stunt the growth of your crops which will lead eventually to its death.

When it becomes a small fly, it deposits its eggs at the base of the cauliflower plants to hatch.   They look like white, legless short worms that often clump in groups.

To control this pest biologically, you can use nematode and wasps.  There are also sticky traps available at most nurseries which can effectively trap cabbage flies.  Using floating row covers at the time of transplant, handpicking eggs, late planting, tilling in the fall and spring seasons will also work.

Other pests that affect cauliflower include slugs and earwigs