What is Virus X in hostas?
Discovered by Dr. Lockhart of the University of Minnesota in the mid 1990s, Virus X in Hostas or HVX, as we shall refer to it from now on, attacks the plant creating quite unusual leaf discolouration and distortions. When a plant starts to exhibit visible symptoms of HVX the damage looks distinctive but HVX can stay dormant in a plant for years before any damage shows. There is a wealth of information on the Internet that shows examples of what to look for - we have selected a few resources for you to follow up in the side column of the newsletter.
It isn't clear where HVX started and although it seems to be more of a problem in the USA it is obviously something we cannot afford to be complacent about in the UK. HVX isn't the only cause of sick looking leaves but it is the most important cause to be aware of because it can spread and there is no cure.

So what do you need to do?
If your plant looks like it may have HVX the only way to deal with it is to destroy it as HVX needs living tissue to survive. This is easy to do with a pot planted hosta but if you suspect a ground planted hosta of infection then you need to ensure you remove all the roots too.

What do we do about HVX?
The vast majority of hostas available on the market are grown in huge numbers, mainly through tissue culture and not all are grown by organisations who actually specialise in the genus. As hosta specialists we certainly cannot afford to take any unnecessary risks. The majority of our sales plants are root-divisions so we have to take special precautions when we propagate. We always clean the entire plant, and our cutting equipment, in treated water prior to splitting. Indeed we do the same thing to pre-treated plants prior to sending them out as bare-rooted orders.
If we spot anything that looks a little odd our first move is to isolate it. We have destroyed a number of individual plants over the years that we suspected might be exhibiting symptoms of a virus and isolated all the others of that variety. During isolation we check the plants for any other exhibiting the characteristics of the destroyed plant but have yet to destroy an entire variety.

Our collection provides us with a ready reference for any potential problem that might be identified in our sales plants. Collection plants are also pot grown and are physically separated from the sales plants in their own tunnels.

Although we cannot afford to fund research into whether our methods of growing hostas actually help prevent the spread of HVX, we do feel we are helping to combat the spread of this disease in a number of ways, including growing all our sale plants plants in pots on raised benches in poly-tunnels.

Whether the plants originate from our own collection stock or are bought in as divisions or tissue-cultured plants (from reputable suppliers) they are all treated with the utmost care. All bought in plants are treated and re-potted in our own soil mix before being added to our tunnel stock. In essence all our plants are physically isolated from each other so if we suspect any form of problem it is a simple matter for us to isolate the plants further by removing them to another part of the nursery where we can monitor further and destroy if necessary.