Identifying, Treating, & Preventing Hosta Diseases

Some possible sources of plant diseases include nurseries, neighbors' yards, plants you received as gifts, or your own yard. Our Best Value TC are guaranteed to be disease-free.  They are tested for diseases before being grown in "clean room" laboratories and greenhouses that are free of diseases. You can be assured our plants will come to you healthy!

Overview of Hosta Diseases

You may want to read a brief disease overview to begin with. Hostas are a low-maintenance plant and quite disease-free. However, you need to prevent diseased plants of any variety to enter your garden and promptly care for remove plants that might be diseased. Some of the diseases are Fusarium, Anthracnose, Viruses, Botrytis Leaf Spot, Foliar Nematodes, Sunscald/ Drought, Crown Rot – Southern Blight, and Virus X. The most common diseases that impact hostas are discussed and illustrated at the links below prepared primarily by universities and extension services.

Remember: HostasDirect's hostas are disease-free!

HOSTA VIRUS X

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.

Many hostas with Hosta Virus X (HVX) have been turning up lately.   This virus can spread and often does not show its symptoms for 3 to 4 years.  It most commonly affects '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 through the transmission of fresh sap and the cutting the plants, and possibly animals feeding on the leaves.  Because symptoms may take years to appear, HVX has infected hundreds of thousands of plants and is at epidemic levels around the world. If a batch of hostas contains any plants that show HVX symptoms, the whole batch should be considered infected and destroyed, as individual testing is impractical and not a guarantee.

You should not buy plants from batches that show 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 your supplier if you see them in your stock. This virus is has spread widely 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 contact of the infected plant's sap with sap of a healthy 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 to get as many roots as possible, and nothing should be planted in that spot until any remaining roots have died and rotted away.  Always sterilize tools and wash your hands after getting hosta sap on them. Reminder: Just one slightly symptomatic plant means that the whole batch is infected.

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Foliar Nematodes

http://www.extension.umn.edu/projects/yardandgarden/ygbriefs/p151nematodesfoliar.html
http://extension.osu.edu/~news/story.php?id=2223

Fusarium, (Tan Spots), (Anthracnose) White to Grayish Spots, (Viruses) Yellow Ring or Lines, (Botrytis Leaf Spot) Brown Spots

http://www.extension.umn.edu/projects/yardandgarden/diagnostics/hosta.html

Crown Rot – Southern Blight

http://www.extension.iastate.edu/publications/sul8.pdf
http://www.extension.umn.edu/projects/yardandgarden/diagnostics/hostasclerotium.html

Anthracnose

http://www.extension.umn.edu/projects/yardandgarden/diagnostics/hostaanthrac.html