Peony FAQ
Q: Ants – Do peony flowers need ants to open?
A: No, ants are not required for peony blooms to open. The ants are attracted to nectar on the sepals of the bud. Once the flower fully opens and the nectar is gone, the ants disappear.
Q: Best Planting Time – What is the best time to plant a peony?
A: Peonies are best planted in the fall when the days become shorter and cooler but the ground remains warm. This provides optimal conditions for new root growth to occur before the soil freezes up in late fall.
Q: Bloom season – When do peonies bloom and how can I extend their season?
A: In Montana most peony bloom occurs in June; of course actual bloom times are contingent upon seasonal weather conditions. There are a few early varieties that flower in May as well as some very late ones that could still be blooming on Independence Day. On average, a peony will bloom from one to two weeks. Some varieties have side buds as well, which are smaller blooms that open up after the main bud. To extend your bloom, choose varieties designated as early, midseason, or late. Look for seasonal designations in the Peony Catalog descriptions.
Q: Cut Flowers – Which peonies make good cut flowers?
A: In general most double peonies make good cut flowers. There are, however, some varieties that are particularly noted for their long vase life and/or spectacular beauty as cut flowers. In addition, some Japanese and semi-double forms make nice cut flowers. Look for that designation in the Peony Catalog descriptions.
Q: Deer – Do deer eat peony foliage or flowers?
A: Peonies are relatively deer resistant compared to many other perennials and shrubs. Over the years I have seen little deer predation on my peonies, and most of my customers have confirmed that experience. However, peonies are not deer proof, especially in areas with an abundance of them.
Q: Diseases – What diseases are peonies susceptible to?
A: Peonies are quite disease free in Montana. The primary pathogen I see here, particularly in damp cool springs, is botrytis. Botrytis is a fungal disease that leaves brown spots on the foliage and sometimes causes the flower buds to shrivel and abort; it also may cut off transpiration in the stems and cause them to die. Prevention is the best course to take. Remove and discard all diseased stems and foliage immediately as they appear with a pruner sterilized after each cut with alcohol or bleach. In the fall after the plants are dormant remove all stems and discard them; do not recycle or compost them.
Q: Dividing peonies – Should peonies be periodically divided?
A: Peonies are very long lived. If they are doing well where they are and you are happy with them, it is not necessary to divide them. If you wish to expand your peony planting, however, peony plants (especially those at 4 or 5 years of age) can readily be divided. The best way to divide a peony is to completely dig it out of the ground, wash off the soil so you can readily see the growing eyes and root mass. Then with a sharp knife carefully cut off pieces that have at least three nice growing eyes and a substantial root mass.
Q: Disbudding – Should peonies with multiple flowers on a stem be disbudded?
A: Removing the side buds when they are marble sized will allow the main flower to grow larger and it will be a bit showier. However, if you wish to extend your flowering season, leave the side buds and enjoy the blooms for a longer period of time.
Q: Fertilization – How do I fertilize my peony?
A: Peonies will perform better if fertilized with a general balanced fertilizer such as 10-10-10. If you are concerned about your specific soil, it is always best to obtain a soil analysis. Peonies will also appreciate a well-aged compost lightly dug in annually in the spring around the crown.
Q: Forms – What are the different types of peony flowers?
A: Peonies bloom forms are classified as follows: single, semi-double, Japanese, bomb, and double. Note that these designations are given in the Peony Catalog descriptions. For illustrative purposes, view the following in the Peony Catalog tab: Sugar N' Spice (single), Buckeye Belle (semidouble), Whitecap (Japanese), Red Charm (bomb), and Joker (double).
Q: Fragrance – Are all peonies fragrant?
A: Some peonies have little or no fragrance; a few even have a slightly objectionable fragrance when cut and brought indoors. There are, however, many peonies with that delightful fragrance traditionally associated with them. The scents can range from sweetly fragrant to lemony or even spicy like cloves. Peonies with a notable fragrance are designated in the Peony Catalog descriptions.
Q: Growing conditions – What conditions do peonies grow best under?
A: For best growth peonies prefer full sun, although they will grow adequately with half a day's sun, such as on the east side of a house. They like a well drained soil with a pH between 6.5 and 7.5.
Q: Itoh Peonies – What is an Intersectional (or Itoh) peony?
A: Intersectional peonies are the newest type of peony. It also is referred to as an Itoh peony, which is a nod to the first hybridizer, Ichiro Itoh, to create this new cross between a tree peony and a herbaceous peony. Itoh peonies combine the best of both peony types – sporting lovely tree peony foliage and flower colors such as golden yellow and lavender/purples only seen in the tree forms. However, the herbaceous peony genes confer more hardiness and allow the peony to become completely dormant in the winter. Most of the Itohs have strong stems that hold their blooms well above the foliage and are outstanding in the landscape.
Q: Mulching – Should peonies be mulched?
A: Mature peony plants need not be mulched and need no winter protection. If peony plants are mulched, however, be sure not to cover the crown, which over time could inhibit the bloom or cause crown rot. Newly planted peony roots should be mulched with straw or wood chips the 1st fall after planting. This is done to help anchor the young plants to protect them from heaving with wintertime freezes and thaws. Place a few inches of mulch around the plant, but not on the crown in late fall when the ground is about to freeze up. Remove the mulch in mid-spring when the soil is beginning to thaw and the stems are about to emerge.
Q: Planting Instructions – How do I plant my peony?
A: Dig a hole at least twice the width and depth of your peony root. You may mix in a small handful of slow release complete fertilizer into your planting soil. If you have good quality compost, you may also mix some of that into your soil. Growing eyes must be covered by between an inch or two or soil; however, do not cover the eyes too deeply or the plant may not bloom properly if at all. Once your root is planted, water well to settle the soil and allow for good root contact with it.
Q: Seasonal Interest – What attributes other than the flower make peonies attractive?
A: Though the bloom is a peony's crowning glory, many peonies have characteristics that make them attractive throughout the growing season. First, many peonies, particularly the lactifloras and intersectionals emerge in spring with lovely burgundy to purplish stems and foliage, eventually turning green after a few weeks of brilliant color. Second, most (but not all) peonies retain their nice green foliage and shrubby appearance until they go into fall dormancy. Finally many peonies sport beautiful buds – some even with a rose-like appearance – for a few days or a week prior to their opening up.
Q: Spent blooms – Should spent peony flowers be deadheaded?
A: For a neater appearance spent flowers and seed pods can be removed on older plants. On young plants that are only a year or two old, it is actually best to remove most of the buds even before they bloom to help the plant build its root mass. It's fun though to perhaps leave one bloom on a newly planted root, however, just to get a preview of what the flower might look like in years to come.
Q: Support – Do peonies need to be staked?
A: Many of the older double peony varieties tend to flop over because the blooms are so heavy, especially with a little wind or rain. However, there are a lot of newer varieties that stand well in the garden with little need for added support. Look for the “Needs No Support” designation in the catalog plant description for peonies that stand well in the garden.
Q: Tree Peonies – Do tree peonies do well in Montana?
A: In my experience most tree peonies do not perform as well in Montana as herbaceous and Itoh peonies. This is because their live branches above ground are susceptible to freezing and dieback during our harsh winters.