Hi.
I have 2 peony plants. One of them has a white dust-like powder on it and large brown spots on the under side of the leaves. The other one is perfectly green. What is this and what can I do about it? Also, will this affect the blooms for next year?

Peonies are wonderful spring blooming perennials. They are one of the most popular, old fashioned garden perennials; their large showy blossoms appear sometime in May, depending on the weather, and will last for weeks on the plants or for several days as a cut flower.

There are two conditions that peonies cannot abide, one is crowded conditions. They need to be located in an airy spot so that air movement will dry out the leaves. This will help prevent leaf disease. Secondly, they can’t take deep planting.

Peonies can be dug and divided in the late summer or early fall, after the foliage has started to fade. To propagate peonies, gently lift the root systems with a digging fork and separate or if necessary, cut root pieces apart. Just make sure that for each new planting, you include a root piece that contains at least three of the buds or eyes- these are the small, swollen bumps on the roots from which the new growth will emerge.

Peonies can also be propagated by seed, although this is not a quick process by any means. Peony seed exhibit double dormancy, so they need a warm treatment followed by a cold treatment to encourage germination. Harvest seed fresh and plant immediately in containers or a prepared seedbed outdoors. Leave the seed alone through the summer (providing the warm treatment) and winter (the cold treatment) In the best-case scenario, the seed will germinate the following spring; worst-case scenario takes 2-3 years.

When planting peonies, only plant the root pieces two inches below ground level. If planted too deeply, peonies will refuse to bloom.

The most common problem with peonies is a disease caused by a fungus—Botrytis blight. You’ll recognize this disease by the black spots on the leaves and stems of the plant.

You can’t get rid of Botrytis blight once you get it, but you can go a long way in the fall to help control it during the next growing season. When the leaves on the peonies have about stopped their photosynthesis for the year, they will yellow. If they are also covered with black areas caused by Botrytis, cut the leaves and stems back and remove and discard the foliage.

The Botrytis fungus can also cause the flower buds to turn brown or black and to wither before they open. Look for gray moldy fuzz on the affected plant parts.

The fungus that causes Botrytis can overwinter on leaves if they are left in the garden. Next year when the growing season begins, the fungus will start to reproduce at the same time chances are very good that your plants would be affected again next year. You can reduce those chances by removing these leaves and cleaning up the garden area well.

It helps to have the proper tools for garden chores like these; extremely sharp shears will cut right through the stems and foliage. Be sure to wipe your tools clean and dry them before putting them away to prevent rust and deterioration.

If you’ve had a real problem with Botrytis this year, you might want to make a note to start a fungicide spray early in the growing season. Remember that fungicides don’t eliminate problems, but they can help to prevent further infection.

Peonies are wonderful flowers for bringing in for arrangements. If you have lots of little ants on your peonies, you can reduce the number that you are bringing in with you by dipping the flower heads into a bucket of water. Hold the flowers by the stem and dip them upside down a few times to drown the ants and then shake off the excess moisture.

Margaret Kulp is an extraordinarily talented local floral designer and she offers these SECRET tips for arranging peonies:

Use a glass vase instead of oasis for peony arrangements.

Burn the stems in a gas flame or candle after cutting.
Remove all the foliage below the water line.
Cut the blooms before they are fully open to prevent shattering.
Do not cut all the blossoms on a plant.

Cut peonies that are in the bud stage –without any moisture on them---can be wrapped and sealed in newspaper and then put in a plastic bag and refrigerated—these stems will last as long as three weeks.