Having blogged in the past about ash tree die back I recently came across yet another plant disease that has the potential to impact greatly on gardeners.  Effecting Aquilegias a cottage garden favourite whose dainty flowers grace many cottage gardens with their pastel nodding ‘bonnets’ through May to July.  These plants are a useful herbaceous perennial for adding dots of interest preferring light shaded areas.  Once established and happy they seed freely providing seedlings that fill gaps in borders and within gaps in paving.  Carrie Thomas, who holds the Plant Heritage National Collection, noticed two years ago some yellowing to the plants leaves. Discounting this as a symptom of the mid wet weather she turned a blind eye to them knowing they often look unhappy with such conditions.  In retrospect this was a mistake.  The Royal Horticultural Society were contacted by Carrie and has now diagnosed the disease to be a hitherto unknown downy mildew, specific to aquilegia. Having wiped out a third of Carrie’s plants in 2014 we can assume correctly that this is a particularly virulent mildew.   Sadly this is a depressing prognosis of decimation of the genus and Carrie’s collection.

This devastating disease is spreading fast with cases already identified in Cardiff, Devon, Hertfordshire, Essex and Surrey and with fewer nurseries supplying more large Garden Centre chains the likelihood of this disease being transported nationwide is inevitable.

With Spring approaching soon and as the sun warms the soil and aquilegias begin to form their clusters of leaves, it is important you are vigilant to the symptoms and know what to do if your plants are infected. This is particularly important as there are no chemical treatments so far for this new downey mildew.

Aquilegia shoots showing new growth- image taken within Mark Pumphreys Garden Mid February

You will need to check the aquilegia for new shoots as they emerge from the soil. Anything that is longer than normal or whitish should ring alarm bells, as should shoots that look stretched, etiolated, curled, lighter coloured with smaller, fern-like leaves with yellow patches.

Other visual tips to look out for that could provide a clue if you may have this mildew are slug and snail trails around your plant. Usually Aquilegias do not get eaten by molluscs due to the toxins within the plant however the mildew itself seems irresistible to slugs and snails

Spring symptoms develop further and leaves turn brown and die, whole plants become distorted and flower buds look blasted. The key symptom is a fluffy, white downy growth on the undersides of the leaves.

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