Cauliflower Pests And Diseases

When it comes to cauliflowers overall they are quite hardy plants and can withstand many changes in weather and pests once they are well established, however there are come common cauliflower pests and diseases that you need to look out for particularly with regards to young plants.

Typical pests and diseases are: -

Slugs and snails – These are the most common pest that any vegetable gardener has to deal with and they are not fussy what they eat so will attack your cauliflowers, particularly the leaves if given a chance. Whilst I could right a book just on how to kill them they are actually quite easy to kill and keep at bay.

Slug pellets can be scattered around the base of the cauliflower stems, making sure you avoid scattering them on top of the plant, as they need to be on the soil not the leaves. Replace after a heavy rain shower. You can also place crushed eggshells around them to keep the slugs away. Beer baited slug traps can also be used to attract in the slugs and drown them. Prevention is better than cure so get your slug prevention methods down the day you plant out your seedlings.

Cabbage worms, often known as cabbage loopers are small green or grey looking caterpillars that blend in with the plants colour making them hard to spot, this is because they take on the colour of whatever plant they are eating! They will eventually turn in to white or light yellow winged butterflies, which can be seen flying around the plants.

As you may by now have guessed the secret is in keeping these butterflies off in the first place, as they lay eggs on the cauliflower leaves, which in turn become the caterpillars. Small gauge netting can be stretched over the plants to keep the butterflies away.

The caterpillars will eat through the plants leaves in couple of days, and this can cause nutrient and water starvation causing the cauliflower plant to die. They can be prevented by using nets as above or by spraying with commercial “Dipel.”

Flea beetles affect the leaves and the roots of cauliflowers

Cutworms – These affect the stems of young plants and as they are nocturnal you can find that you wake up in the morning to find your seedlings eaten to nothing but with no predator in sight. They are small caterpillars around 1 inch long and striped green, grey or brown. During the day they will be below the surface at the soils moisture line. To control them place cardboard collars around seedlings extending 1” above and 2” below the seedlings, old toilet roll tubes are ideal.

Root maggots – Sadly these can affect the whole of the cauliflower plant. They look like common white maggots and as their name suggests feed on the roots of the plant. They are caused by normal looking flies that do not actually fly very well, they lay their eggs in the soil at the base of the main cauliflower root, and these then hatch in to larvae that tunnel in to the plants roots. This causes little brown tunnels to appear in the roots, which can destroy the plant from within. Unfortunately this can occur 2 or 3 times each season. Root maggots can be treated by applying Diazino pesticide to the soil before planting your cauliflowers.

Aphids – These are a very common and persistent pest, however they can be easily treated. The aphids affect the leaves and take the form of very small black, white, red or green insects that almost just look like tiny larvae. They eat in to the leaves and this causes a sticky honeydew secretion to form on the plant (Which in turn can attract ants). The aphids can be treated by spraying them with a strong stream of water, or washing the leaves with soapy water. They can be treated with insecticides such as Diazinon or Sevin.

Soft rot – This is a bacterial disease that affects the cauliflowers leaves. It can be identified by the leaves turning yellow at the edges, this will then spread inwards. It will then infect the main stem and turn the inside of it black. This bacterial soft rot will either kill the plants or cause them to grow just to a dwarf size if it affects the plants where they are young or it will cause older plants to lose their leaves and thus their ability to collect enough water to grow.

Damping Off – This occurs when young seedlings are overwatered and can cause them to wilt and die, however it can be easily avoided by letting the soil dry out in between waterings e.g. avoid having making the seedlings always damp.

Learn How To Grow Cauliflowers if you haven't tried them before

By Richard Allen -