Pests and diseases that can affect lavender
As well as making a beautiful addition to your garden, lavender also emits it’s well-known calming aroma to transform the space into a place of utmost tranquillity. As far as pests and diseases go, lavender is justifiably renowned for being remarkably free them – but it isn’t entirely immune. Here are a few things to look out for, that could affect your lavender.
Cuckoo spit is more of an unattractive nuisance than a real threat, though the first meal of the green capsid bug growing inside the unpleasant foam will be your lavender plant’s sap. Fortunately, the solution is simple and chemical-free – just spray it away with water!
Whitefly are occasionally attracted to lavender but it is rare for the plants to become truly – and fatally – infested. If the whitefly population is allowed to multiply, growth will become less vigorous and the leaves will yellow. The solution is vigilance and removal by hand – there are no properly effective pesticides available. A water spray will evict adult whiteflies.
It’s often thought that lavender deters both green and whitefly, and helps reduce their numbers in the immediate vicinity. Although this may be true, there is no reliable scientific research to support the theory.
Aphids may settle on lavender but rarely inflict the damage they can on other plants. The even rarer – but far more serious – threat posed by aphids is the Alfa Mosaic Virus…
Alfa Mosaic Virus
The Alfa Mosaic Virus is exceptionally infectious and spread by both aphids and human contact. It is also fatal. Look out for leaves developing patches of yellow and then contorting. Any infected plant should be dug up immediately and with great care – wear gloves, don’t let your clothes touch it and wrap the plant in newspaper, an unwanted towel or a plastic rubbish sack before handing. It (and anything that has been in contact with it) must then be burnt – don’t compost, don’t send it to green waste. If you can’t make a bonfire, bag it up securely and dispose with your non-recyclable rubbish.
Shab (Phomopsis lavandulae)
Shab is a fungal infection that kills the branches of lavender plants. The good news is that it is extremely, exceptionally rare in UK gardens. But don’t be complacent – the signs to look out for are shoots that suddenly wilt when there is no drought and stems that turn brown before developing black spots. Infected plants should be carefully dug up and burnt as above.
Despite these two horror stories (and we must stress they really are rare), the plain truth is that the main threat to lavender is the inattentive or careless gardener – more lavenders die because they have been planted in full shade or in soil with poor drainage than are ever killed by rapacious bugs or a virulent virus. So be sure to take good care of your lavender to keep it looking bright and beautiful!
Head to our lavender hedges page to find out more about the benefits of growing this fragrant and useful plant, and to browse our range of lavenders for sale.