Tree Peony Care Instructions

Site Selection: Please take time to prepare your planting area. In return you will receive a lifetime of enjoyment. In 10 years, most plants will grow to 4'x4'. If planting a group of tree peonies, allow at least 4 to 5 feet between them. Do not plant closer than 8-10 feet from large trees, where tree roots will compete with the peonies for nutrients and water. Choose a location with 4-6 hours of direct sun, or dappled sun/shade all day. Full sun will make the flowers fade rapidly. Full shade will result in weak and very slow growth.

Watering: This is the most common misunderstanding. Tree peonies do not have watering needs like roses or other perennials. They are woody shrubs native to northern China, which receives about 30 inches of rain per year. Once established, tree peonies are drought tolerant plants. Excess water will suffocate the roots and is the leading cause of plant failure. Do not plant near auto-sprinkler systems that keep the soils continuously moist. Do not water until soil is dry below the surface and try not to wet leaves when watering to prevent fungus. Be observant; soil can dry out on top and still be moist 6-12” below the surface. When you feel the soil is dry below the first 4-6”and leaves may droop slightly, water the roots deeply. Climates of hot summer temperatures with little or no rain at all will require more attention to watering then those areas that get some rainfall. Peonies in root control bags will require more watering attention than tree peonies planted in the ground. NOTE: Droopy leaves in the first warm days of spring are caused by an imbalance of the root system and leaf production. If soil has moisture, do not water. This imbalance that will self correct as the plant settles into the growing season. You know this is the cause of the limp leaves if the plant recovers in the evening or early the next morning.

Failure to follow our directions on watering will give unsatisfactory results. We cannot be responsible for plants that die due to excess water.

Spring Care: In areas of damp, cold spring weather, using a copper spray will prevent fungus that discolors the leaves with black spots later in the season. Use Basicop sold in most garden centers, or Soap Shield from Garden's Alive ( tel. 812-537-8650). Mix according to package directions. Use in early spring when the buds start to open, 3 treatments, 10 days apart. This will prevent spotting that shows up later in the season. If you do see fungus in late spring or summer, remove heavily damaged leaves. Late season spraying seems to have no effect on peonies. Spraying must be used preventatively. This fungus rarely kills the plant, but will slow its growth. If you have a problem one year, remember to treat for it early the following season.

Fertilizing: For optimum growth and vigor, fertilize every 2-3 weeks with 1 oz. to one gallon of fish/seaweed fertilizer such as Neptune’s Harvest. If it is raining frequently, mix 1 oz. fish/seaweed to 1 cup of water and sprinkle at the drip line of the plant, letting the rain pull the food to the roots.

Summer: The hot weather is a time of dormancy, with little or no leaf growth. Plants are storing energy in the roots and will make buds for next season in late summer. Continue to fertilize plants until about one month before the frost date in your area. Water plant when it seems dry 4-6 inches below the surface of the soil; water deeply, allowing plant to dry out again before the next watering.

Fall Care: About the time of the first frost, remove the leaves to prevent any over-wintering of fungus. Do not cut the woody stems; flowers bloom on old wood. Check for borer at this time. You will sometimes find a hole drilled into the woody stem on older plants. The pest known as the "Rose Borer" will sometimes drill into the pith of larger stems. Cut off affected area or take a thin wire and poke into the hole, killing the larvae. Seal hole with white glue or clay.

After fall cleanup, we like to add a little compost and a cup of lime to our acidic New England soil. Lightly dig in around the drip line . Tree peonies in China grow in soil with a pH of 7.0 or higher, so we feel it is important to maintain pH at this level for optimum growing conditions.

Mulch plant well in zone 4 and colder parts of zone 5. Warmer climates seem to be fine with little or no mulch once plants are established. Here in our zone 5b climate, we use just a couple of inches of mulch on established plants.

Pruning: Oncer your tree peony is growing for several years and has many branches, it may be necessary to cut out extra growth in the interior of the shrub. Select 6 to 10 of the strongest branches as the major stems of the plant. This will allow the peony to concentrate its strength on flowering in its main branches, rather than excessive leaf growth. It will also eliminate chances for fungus to grow, allowing more light and air to circulate in the plant. If you prefer to see the wood of the tree peony at the base, you can prune out leaf buds low to the ground. This is a Chinese style of shaping. The natural habit for most Chinese tree peonies is a very dense, spreading, rounded form, though some varieties, like White Screen Reflects a Blue Jewel, Phoenix White and Lotus that Shines in the Sun are naturally tall and woody at their base.

Remember the Chinese proverb, "The gardener's footsteps are the garden's best fertilizer".