Courgette Pests And Diseases

In general I would say courgettes are very easy to grow and once established there are few pests and diseases that will affect them. Indeed if you are looking for a vegetable that is easy to grow then look no further.

The only time real care needs to be taken is when they are seedlings, as when first planted out they are susceptible to attacks from slugs and snails. When they are more mature plants the slugs and snails do not seem to want to attack them.

Slugs and snails – if you find mysterious holes eaten in the leaves, and slime trails on the soil overnight then slugs or snails will be the culprit. The good news is whilst they are a common pest they are easily treated with slug pellets, or you can use slug traps, both of which will effectively kill snails as well as slugs.

Another alternative and one favoured by many gardeners is to go out at night with a torch after dark and use it to find the slugs, pick them up and kill them. Killing slugs and snails is the most effective treatment, as if you throw them away over a fence they will use their magical sense of smell to have crawled back to your courgette plants by the next night.

Powdery mildew – This disease is the most common one to affect courgettes and most gardeners will find it affects their plants at some point in a season or two. It is very easily spotted as it looks like a form of light grey powder covering a large area of the leaves, which feels like a powder when touched. It can have a novice gardener wondering where it has come from as it can look like someone has scattered a powder on the plants overnight.

It is caused by the plants remaining damp for too long, and so whilst it is good to plant your courgettes in well drained soil, it is more important to plant them in a well ventilated area so that the leaves dry quickly after rain or watering. It can be treated by removing the infected leaves and spraying the courgette plants with a copper based fungicide to prevent it from occurring / re-occurring. If untreated powdery mildew can cause the plant to become malnourished and grow weak.

Aphids can be a problem but far less so than on other garden plants as the courgette flowers tend to attract other flying insects that like to feed on aphids as well.

Powdery mildew and slugs can both be spotted early on and treated easily if you pay regular attention to your courgette plants.

For more details see How To Grow Courgettes

By Richard Allen -