Hostas have long been the number one garden plant. Now there is a virus called HVX or Hosta virus X that can kill your Hostas. If you are a collector of Hostas, this is a virus that you do not want in your garden. If you are not familiar with this virus it has become a major problem in America and Europe. Hostas that have HVX should be destroyed. There is NO treatment or cure for your plant. The disease is transmitted by sap from an infected plant to another plant by mechanical means. If you prune leaves from an infected plant and then prune another Hosta plant, you will spread the disease. Cleaning and disinfecting your pruners will not stop transmittal of this virus. How do you know that your Hosta plant has HVX? You may not know. A plant can look healthy and be infected. It may take up to a year for signs of the virus to appear in a healthy plant. When you purchase plants inspect them carefully and if they have unusual markings or do not look healthy, walk on by. The normal signs of infected plants are:
- Deformed or malformed flowers
- Less vigor in growth
- Brown or dead spots on leaves
- Spots, streaks, line patterns, mottle or mosaic patterns on leaves
- Death of the plant
If you remove an infected plant (including roots) it is safe to replant a new Hosta in the same spot. The virus does not stay in the soil. There is now a test kit available for testing Hosta. I had the opportunity to test a plant using the test kit and found it easy to use. You take a piece of the leaf, about the size of a quarter and place it inside the plastic test bag. The testing bag contains a clear liquid buffer. You then rub the plastic bag with the leaf sample inside. As you rub the leaf, the clear buffer turns green from the leaf chlorophyll. You then insert a test strip into the liquid inside the bag and it will show positive or negative for HVX. If it comes up positive, destroy the plant. The test kits are available from Agdia or you can go to their web site at http://www.agdia.com/.
A suggestion from a Hosta grower and collector is to purchase heavy duty plastic table knives and insert one in the dirt around each individual plant in the collection. The knife is used for pruning that plant only. This method will help to eliminate exposing all plants if one Hosta does have HVX.
The Creative Gardener