Herb Pests And Diseases

When it comes to growing herbs then pests and diseases are in general very rare but there are still some that can affect herbs and prove devastating if untreated. However as herbs normally grown in small batches then it is easy to spot them and treat them accordingly.

Aphids are the most common pest to affect virtually all herbs, whilst they look small (if not tiny!) these microscopic insects reproduce faster than you would believe and thrive in hot and humid conditions in particular.

They can be prevented by spraying the plants with a very mild solution of jeyes fluid at the start of the growing season, they can then continue to be treated by spraying them with mild soapy water every few days, taking great care to spray the underside of the leaves. This is because this is where they are laid as eggs and sit out of site often only first showing themselves by climbing up the plants.

Celery leaf miner – this is another common pest that simply tunnels in to the leaves leaving a thin trail of dead leaf tissue. Cure by removing the infected herb leaves.

Carrot fly – this can affect parsley, the green leaves of which do not look so unlike carrot leaves. They will lay eggs in the parleys roots, the larvae of which will then tunnel into the parsleys roots, causing the parsley to wilt and die as the roots become no longer capable of getting enough food and water to remain healthy. The affected herb will then go yellow and die. Control using a suitable insecticide periodically as prevention is better than cure.

Mint rust – as the name suggest this disease affects mint! It appears as rusty orange powdery spots on the underneath of the mint leaves. Unfortunately if your mint plant gets this it has no cure. It can be prevented by lifting out the mint plants in early season and washing the roots in moderately hot water for a short period, cool them down in cold water before replanting the mint.

Mint rust can also affect chives in a slightly different way in a milder form, and if it causes severe damage to the chives the plants will be beyond hope and need to be thrown away.

Overall most herb pests and diseases can easily be spotted, the key is regular checks on them for the above herb pests and diseases.

By Richard Allen -