home

catalog

peony care

plan a garden

events

visit

TREE PEONY CARE

It's Peony Planting Time
Whether you are noticing the approach of spring or the onset of fall it is the perfect time to plant tree peonies.  In fall, plant before the permanent frost settle. In spring, plant bare root peonies as early as the ground can be worked and before the plants have leafed out. Plant potted tree peonies in May or as soon as purchased. Plant in an area that is free of tree roots, where the soil is neutral and well draining and where there is partial sun. Tree peony's grow well in zones 3-8. We do not recommend planting peonies outside of these zones as they will not survive. For more information on your horticultural zone visit the National Gardening Associations website.

Bare-Root or Potted Tree Peonies
Healthy tree peonies consist of 2 to 5 stems on a strong root system. All of our tree peonies except the gansu varieties are on their own roots - not grafted onto an herbaceous root - thus ensuring that only a tree peony will grow and not its herbaceous nurse root. Bare-root tree peonies are planted September through April. Potted tree peonies are planted in May.

Site Selection
First, consider placement. Tree peonies should be planted where there is little competition from other large trees or shrubs. Give your plant a good 3 to 5 feet of space that it can grow in to. Dwarf varieties will require less space; mid and tall varieties more. Remember that your plant is slow growing and will take time to fill in this space but plan accordingly as they do not like to be moved.

Second, consider soil conditions. Peonies tolerate a wide range of soil conditions. Ideally, you want neutral to slightly alkaline soil that has good drainage and high organic content. Peonies planted in clay soil, amended to ensure good drainage, take longer to become established but produce beautiful plants as clay soil retains nutrition.  Peonies planted in sandy soil take less time to become established but can produce less striking plants as nutrients easily leech out of the soil. If planting in sandy soil, amend with clay and compost and top dress several times a year with compost to renew the soil. Regardless of soil conditions, tree peonies need soil that drains, as peonies cannot tolerate wet feet. 

Third, amount of sun. Tree peonies are tolerant of a wide rage of sun conditions from full sun to dappled shade. Ideally, your tree peony wants morning sun and afternoon shade, or dappled sun throughout the day. This will give your tree peony ample sunlight while prolonging the life of the flowers.  If you grow your tree peonies in full sun, consider using wax paper umbrellas to prevent the flowers from fading. Varieties with numerous petals will hold up in stronger sun than those with fewer petals. See guide to shapes and colors to help select varieties for your garden.
Forth, extraneous factors. If you live in a location prone to heavy winds, consider planting your tree peony near a windbreak. If your area is prone to heavy snows consider planting your tree peony away from eves or plow lines to protect the tree peony from heavy downfalls of snow that can break the branches. If you are in horticultural zones 2 or 3, consider some winter mulching. In most gardens, however, tree peonies need no winter protection as they are cold hardy and resilient. 

Planting
As your peony prefers to be planted and left in one location for generations, it is worth taking the time to amend the soil.  If need be invest in a soil test from your county’s agricultural extension service. Dig a hole at least the size of a five-gallon pot and amend your soil as necessary to produce a friable loam. Clay needs compost and quarry dust. Sand needs clay and compost.  Add a slow release fertilizer that is low in nitrogen and bone meal.

Tree peonies should be planted deeply. The plant should be buried so that the join of the root and the stem is two inches below the surface of the soil. This will promote additional branches to emerge from the base. All of our tree peonies (except the gansu mudan varieties) are on their own root, not grafted, and new shoots from the roots should be encouraged to provide a shapely plant. The gansu mudan varieties are grafted and should be planted even more deeply - the graft should be six inches below the surface of the soil. This deep planting forces dieback of the nurse herbaceous root and successful growth of the tree peony root. Any herbaceous shoots noticed growing from a gansu variety should be cut back and the plant should be mulched to more deeply bury the root.

During the first two growing seasons after planting a new tree peony, ensure that it gets a good soaking every two to three weeks.  This keeps the plant from being stressed by drought as it develops its fibrous root system.  However, remember that peonies do not like wet feet and be careful to not over water. 

What to Expect
Tree peonies, like most perennials, take about three years to become established in your garden. They follow the well known truisms - first year sleep, second year creep, third year leap - or first year roots, second year shoots, third year flowers. You can often expect small flowers on first or second year tree peonies but the flowers you are looking for typically come in the third year. Tree peonies will grow five to ten inches of green growth every year. Part of this green growth will become next year’s woody branch. 

Beautiful Cut Flowers
Tree peonies make some of the largest cut flowers. They can be floated in large glass vases and bowls making an incredible statement on any table. Stems should be cut short, about one inch, to avoid cutting off what will become next year's woody stem.

Fall Care
Tree peonies are self-reliant requiring little care in the fall. Unlike herbaceous peonies, tree peonies stems do not get cut back. Fastidious gardeners can trim back the leaves to the stems and in severely cold climates - horticultural zones 2 and 3 - they can be screened with burlap to protect from winter winds and heavy snow. Also different from herbaceous peonies, tree peonies like mulch. A light layer of nutrient-rich mulch or compost will feed and protect your plant in the winter. Avoid mulching with wood chips however as the fungus that decomposes wood chips can infect tree peonies. For the most part, however, tree peonies do not require any special fall or winter care.

Prune for shape only. Prune just as the flowers are fading as next year’s flowers develop early on existing wood. Never prune more than one-third of the plant at one time. Use a sharp set of pruners and cut at an angle just above the place of a new bud.

Diseases/Insects
To prevent disease make sure your garden is kept clean, that air circulates, and that plants are kept healthy. Messenger™ and Neptune’s Harvest™ are two organic products to keep your plants healthy and disease resistant.

Powdery Mildew - leaves turn white. Onset is in late June through September.  It is not fatal and tree peonies are less prone than herbaceous peonies to this fungus. In some years powdery mildew is worse than others. It can infect plants when there are hot days, high humidity, and cool nights. Once the plant is infected, simply remove the leaves for no amount of spray or oil will rid the plant of powdery mildew this year. Some preventative remedies include the following: Bacillus subtilis to boost plant’s natural defenses, rhubarb leaf tea, backing soda spray (1t backing soda, 1qt. water and a few drops of liquid soap), cornmeal as a soil amendment or mixed as a spray, neem oil, products containing sulfur, or a biofungicide recommended to treat powdery mildew on peonies. The cooperative extension service in New Jersey recommends potassium bicarbonate at 7-10 day intervals.


Botrytis - young stalks wilt and die, buds turn black. Onset is in early spring when temperatures remain below 70 degrees. Botrytis will kill tree peonies if not treated. Botrytis thrives in cool humid conditions and can be minimized by planting peonies where they have good air circulation. When noticed, cut off diseased portions of the plant, dipping the pruners in a 10% solution of bleach between each cutting to ensure you don't spread the disease. Throw out the diseased portions, do not compost. A more aggressive option would be to use systemic fungicide labeled for use on peonies. The cooperative extension service of New Jersey recommends ferban, maneb, and triflumizole from the time buds are pea sized until plants are ready to bloom.

Various Funguses/Diseases - There are several diseases that can cause blotches on the leaves or cause the plant to turn black, wilt and portions to die. When in doubt, send a sample to your county’s agricultural extension office for laboratory diagnosis and treatment recommendations. But in general peonies are disease resistant and require very little care.

Ants
Ants are not as attracted to tree peonies as they are to herbaceous peonies as the buds do not produce as much nectar. Remember that ants can be beneficial for the garden.

Transplanting Peonies
If you are lucky enough to have mature tree peonies in your garden and want to transplant them, the time to do this is in the fall when the plants have become dormant. Dig the new hole first and amend the soil as necessary. Then to lift your established tree peony, beginning at least eighteen inches from the base of the stem, loosen the plant from the soil with a large garden fork, work your way around the plant, and gently pry it from the ground.  The roots will be deep and tough. Have burlap ready to help secure the root ball. Plant immediately and water in well. Note that when moving a tree peony it will take several years for it to return to its previous health.