HOSTA VIRUS X

Fall 2007 Update

More Photos of HVX-infected plants  Page 1 Page 2 Page 3           Infected Cultivars in the Marketplace

Symptom Identification      Other Viruses in Hosta     Hosta Virus Myths

    Many hostas are turning up that are infected with a virus called Hosta Virus X (HVX). The most commonly seen ones are plants of 'Gold Standard', 'Striptease', and 'Sum and Substance', but other common varieties are being reported infected in large numbers. While this disease does not kill plants, its primary danger lies in its proven ability to spread prolifically. Because symptoms may take years to show after infection, HVX has infected hundreds of thousands of plants and is at epidemic levels around the world. If a batch of hostas contains any individual plants that show HVX symptoms, the whole batch should be considered  infected and should be destroyed, as individual testing is impractical and not a guarantee.
    If you are a gardener, do not buy plants from batches that show even the slightest markings on even one plant. If you have these plants from batches that show symptoms at your home, dispose of them immediately. If you are a grower or vendor, learn what the signs are and contact the supplier if you see them in your stock. This virus is widely spread at this time in the above plants and others (see table of infected cultivars) and the source nurseries are still learning about the problem as of 5/06. Only testing with the specific ELISA kit for HVX can detect HVX. Very large numbers of HVX-infected plants are still currently being sold at all levels.
    This virus is transmitted primarily through cutting the plants. Contact of the infected plant's sap with sap of a healthy plant will infect the new plant. This can happen whenever cuts are made and the instruments or hands are not disinfected afterwards. Dividing hostas, removing bloom scapes, removing leaves, stepping on them, even accidentally running the lawnmower over them can and will spread this virus. It survives only in living plant tissue and dies without a host. Plants in pots may be simply disposed of or burned. Plants in the ground should be dug carefully as to get as many roots as possible, and the spot should not be replanted until any remaining roots have died and rotted away.

Hosta Virus X in 'Striptease'.Note green lines in center of leaf.

Heavy HVX symptoms in 'Sum and Substance'. Note how green tissue is looking thin and wrinkled.

HVX-infected 'So Sweet' held to light to better see mottling.  

'Gold Edger' with HVX. Note sunken, glaucous green areas.

'June' showing classic "inkbleed" symptoms along the veins.

'Blue Cadet' showing lighter "inkbleed" areas along veins.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

All material in the Hosta Virus X section of the HostaLibrary, including photographs, is intended for free use as a public service. Please feel free to copy and use to help us contain the spread of this disease.

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More Photos of HVX-infected plants  Page 1 Page 2 Page 3           Infected Cultivars in the Marketplace

Symptom Identification      Other Viruses in Hosta     Hosta Virus Myths