Found for the very first time in 2003, Downy Mildew is a disease caused by the fungus-like organism Plasmopara Obducens.

Downy Mildew is only likely to occur during wet summers and the recent outbreak was confined to Impatiens Walleriana, commonly known as the Busy Lizzie.

Have your Busy Lizzies suffered?

If so, you’ll have spotted the leaves of the plants turning yellow before rapidly shedding, as well as a fine white fungal growth on the lower leaf surface. You’ll have also noticed that the flowers will shed much faster and the plant has been reduced to bare branches with just a small tuft of yellow leaves and flower buds at the top.

So, how do you control Downy Mildew?

Dispose of affected plants as soon as possible by burning them or burying them deeper than 50cm. As soil contamination may occur, rest affected areas from Impatiens for at least a year, as some species of Plasmopara affect other plants and produce resting spores that can survive for years after.

If you’ve grown Busy Lizzies in containers and they’ve become infected, simply replace the compost and wash using a garden disinfectant, following the instructions on the bottle. This is to cleanse the container if you wish to grow Impatiens in it the following year. Any other bedding plants, however, can be grown without risk as the disease is specific to Impatiens.

Now for some good news…

Here at Gardening Direct we stock a range of Busy Lizzies, many of which are resistant to Downy Mildew. Take a look at our range at www.gardeningdirect.co.uk.