Downy Mildew Disease Killing Plants | Love The Garden

Busy Lizzie Problem - Impatiens Downy Mildew Disease Killing Plants

Geoff Hodge's picture
By Geoff Hodge, Botanical Expert (BSc, MCIHort)
busy lizzie


I’ve been doing a lot of gardening question time roadshows recently, and one question that regularly comes up is: “What’s wrong with my busy Lizzies – they’re dying?”

The answer, sadly, is a disfiguring disease that is killing busy Lizzies (impatiens) all over the UK. Impatiens downy mildew is a relatively new disease. It was first discovered in the UK in 2003, but there was never a real problem with it until a couple of years ago. But this year, probably encouraged by the cool, damp summer weather, it has run riot in gardens – killing plants wherever it appears.

Unfortunately, the disease is proving ‘difficult to control’ on the nurseries growing and supplying the plants, with even approved professional fungicides proving ineffective. This could indicate either the presence of a new ‘aggressive’ form of the disease or that it has developed resistance to the fungicides.

For us gardeners, there are no approved fungicides for its control – so there’s nothing we can do once it strikes in our gardens. All this means that it could be the end of the busy Lizzie as we know it. If the plant nurseries can’t control it – then they won’t be growing them – and if we have no approved fungicides to use at home, once it appears on our plants that’s it.

There is one possible ray of hope. The Sunpatiens varieties seem to be resistant to the disease. These plants are bigger and more robust than your common or garden busy Lizzie and it may be this that provides the resistance.

If you’ve had any problems with your busy Lizzies and impatiens downy mildew disease, please let us know.


Gardening Roadshows

The last gardening question times for 2011, sponsored by Miracle-Gro, are:

September 10-11: Essex County Show, Barleylands, Billericay
September 17-18: The Cambridge Food, Garden and Produce Festival, Parker’s Piece, Cambridge

Come along and say hello and get your gardening question answered. We’ll even be asking you questions and if you get them right you can win some gardening goodies.


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