Ms. Eudora’s Garden Tool Blog

Peonies are living plants, and like anything that lives they are susceptible to forms of infections and viruses, White Mold, Viruses and Wilt are common peony diseases.  When planted properly and given proper growing conditions, the peony can be grown almost disease free.  However when the weather is more wet, rainy and humid for a period of time the plants will suffer. These are some ways to check for diseases if your peony plants are looking wilted or their growth seems to be stunted.

Wilt: Check the base of your plant, and if the base looks good but the shoots are wilting it may have what’s called Verticillium Albo-Atrum, a soil- born fungus and one that is almost impossible to get rid of. Cut off a piece of the stem and check the cross section to see if it is brown (it shouldn’t be) this is the plants self watering system.  If it is check with your local county extension office (County Dept. of Forestry) you will want to make sure before removing and discarding your plants.

White Mold: This fungus will cause the stems to rot on not only your peonies but other herbaceous plants in your garden as well. White Mold will cause a portion or sometimes the entire plant to wilt.  The infected part of the stem will become dry and stringy and tan in color.  If the weather conditions are humid a fluffy whit mold will appear.  To diagnose this, slice the stem lengthwise and check for signs of irregular sizes of hard black sclerotic that will be inside the tan area of the stem.  Sclerotinia is a soil inhabiting fungus that is also nearly impossible to remove. Because it has the over wintering structure it can last in the soil for years.

Virus Disease: Shows in the forms of ring spots, mosaic, leaf curls and or elongation.  If your plant has a virus, the leaves will be light and dark green in color, stringy and curly.  They will also have a reduction in growth and will be less vigorous.  They will however continue to grow and bloom as usual except they will have a strange pattern on their leaves.  No treatment is recommended for this but if it becomes severe remove and discard the plant.

There are fungicides available to treat Wilt and Whit Mold but nothing will cure it.  In the fall cut back your peonies and in early spring when the red shoots first start to appear start to treat the new shoots then.  Treat the stems and buds at the beginning of the growing season to help prevent infestation.

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