Gardening with Gary

Gardening Advice from an Expert

Peonies

Peonies provide an old-fashioned special attraction in northern gardens during their short bloom period. The pink, white and rose fully double flowers last only a week or so, but by selecting early, midseason and late varieties, you can extend the display up to eight weeks

For all-season color, plant peonies with spring-flowering bulbs, followed closely by summer-flowering bulbs, corms, and tubers, so that there is a full season of color. Take notes of where you planted what, so they are not accidentally disturbed when the foliage has died down and the plants are not visible.

Or, plant them with iris, daylilies, mums, and asters. Also, the tall foliage of peonies make good background plants for low-growing annuals all summer long, as marigold, ageratum, pansies, and dwarf versions of many popular annuals.

Consider these factors when choosing a location for your peonies:

Peonies need at least six hours of sun a day. Any less that they will not flower well.

They enjoy a good, rich, organic soil with a pH between 6.5 and 7.2.

Since strong winds easily rip apart the blossoms, plant peonies in a protected area. A fence or wall near them assists.

Provide good drainage. Spade up the beds well, to break up solid pieces, especially if the soil is clay. If drainage is a problem, use a raised bed. The plant will be almost as wide as it is tall (about three feet) so allow plenty of room. They love to grow out, but not up so much.

Don't plant near the roots of trees or large shrubs. These plants will take away a lot of the needed water and food. Also, the competition for moisture and nutrients will cause the peony to produce smaller flowers.

No matter the soil, be sure to feed them weekly one you see spring growth, for larger flowers and greener foliage.

Peonies Not Flowering:

Q. I have two peony bushes, purchased at the same time, planted near each other in identical environment. One blooms quite nicely, the other produces a few small flower balls that shrivel up. Not a flower from the plant.

A. I would have to see the bush to be 100% certain, but I feel that the second one has a root or stem fungal infection. It probably came with the bush when purchased, as the other ones does not seem affected yet.

I would recommend pulling out the sickly one and planting some other type plant there, not another peony, for a couple years. Maybe there would be another spot to place a new peony if you really wanted another. I fear that the fungus may spread to the healthy one and may infect a newly planted one in that location.

If you prefer to wait a while longer, dig up just a patch of the root system, bag in clear plastic and take to a nursery for examination. But either way, I would not wait much longer, as if it is a fungus, then it will spread. You should buy a fungicide to treat the surrounding soil, too.

Q. I love peonies but mine bloom very little and only last several days. Am I doing something wrong? When can I plant new bushes?

A. Peonies are so wonderful in spring gardens [zones 5 to 10, check variety information] but their short bloom period is unfortunate. The flowers last only a week or so, but you can extend their display another six weeks by choosing early, midseason, and late varieties. Check your local nurseries or order from catalogs or online.

Also, you can provide color all season long by planting spring flowering bulbs, iris, daylilies, snapdragons, pansies, and later chrysanthemums and asters around the bushes.

Plant your new peonies in the fall right when planting spring bulbs. Dig holes larger than the root volume. Add some organic material to the soil. To ensure flowers, plant the bushes shallow, so that the top buds on the roots are just below the surface, maybe 1-2 inches. Fill around the plants, do not tamp down, and water well. Keep watering until frost so that they are well established before winter.

Member J/M writes~ When transplanting in the fall, do you cut back the Peonies before doing so?

A. Yes, you should, but read these descriptions first:

If you intend to move some of your peonies, if they have outgrown their space in the garden, or you wish to increase their number, the fall is the time to dig up and divide the clumps. A garden fork is the preferred tool for digging established plants because it minimizes damage to the root system. Lift out the part to be transplanted.. Remove most of the soil from the roots. Using a sharp knife, cut sections of the clump that have at least three "eyes" and sufficient roots. The eyes are the reddish buds located just below the crown of the plant.

Moving established plants is a simple procedure. Cut the peony stems near ground level in September. Then carefully dig around and under each plant. Try to retain as much of the root system as possible. Promptly plant the peony in a sunny, well-drained site. Division of large peony clumps requires a few additional steps. After digging up the plant, gently shake the clump to remove loose soil from the root system. Divide the clump into sections, making sure each division has at least 3 to 5 eyes (buds) and a good portion of the root system.

When replanting the peony sections dug up, make sure that the eyes are no more than 2" below the surface of the soil. If they are planted too deeply, the plants will not bloom. Make sure to water the new plants well, and continue with weekly irrigation through December, or whenever the ground freezes. If you don't need to move your peonies, don't disturb them. They enjoy staying put, and do not need division to thrive.

Assistance from Iowa State University, Ames, IA

Q. I am clueless as to how to plant peonies and what sunlight they require. Can I grow them down by a creek bed?

A. Peonies need at least six hours of good sun per day. They enjoy a humus, rich soil with a pH between 6.5 and 7.5. Since strong winds easily tear apart the blossoms, plant peonies in a protected area. Provide good drainage and if lacking, plant in a slightly raised bed. The plant will be almost as wide as it is tall, about 3', so allow plenty of room to grow out. Do not plant near the roots of trees or large shrubs, since the competition for moisture and nutrients will cause the peony to produce smaller flowers. Feed monthly with a good all-purpose fertilizer.

Janice writes~ I live in zone 7. My grandmother planted her peonies about 40 years ago and recently I have noticed they are not blooming. First, should I dig them up and re-transplant them or is there another solution? I really would like to save them...greatly appreciated.

A. I would recommend that you fertilize the plants. It is probably a bit late now [April] but you should feed them with a high Phosphorus [the second number of the three on the label] fertilizer in the fall before frost and then a couple times again in the early spring as soon as the ground is warm enough to accept water. This is the mineral which encourages flowering of most plants.

Also, buy a soil pH and nutrient testing kit at the nursery. Test and see what you have around them. Peonies like a neutral 7.0 or slightly acidic down to 6.0. Too high and there will be no flowers.

Dig and divide your plants in the early fall. replant so that the crown of foliage is right at the soil line or down to only 2", not any lower. By separating the plants, new feeder roots will form and if the plants have gradually sank in the soil through the years, this can be corrected. Peonies will not bloom if planted down.

Once they are established, you will be rewarded each year with an abundance of beautiful flowers. Peonies can live more than a hundred years if you take good care of them. There are seven hundred years old tree peonies in China. Each of those can still produce two hundreds flowers every year. So, all is not lost!

Here is a good page for diagrams:

http://www.paeonia.com/html/about_peonies/how_to_grow_peonies.htm

Posie writes~
I have been searching the web, top to bottom and back again, looking for specific info on judging peonies. So far have been entirely unsuccessful. Any help you can give will be truly appreciated.

A. I recommend that you contact:

Olga Sandilands
Email: O.Sandilands@aci.on.ca

Guest website: http://www.nhs.usethis.com/interviews/2002/septoct/interviewsept.html

Here is a portion of what she wrote:

Peonies & Flowering Shrubs

Make sure your peonies are the freshest cut they can possibly be. Peonies tend to go off quickly when they are cut and they will fade at the edges. A winning peony will have consistency of colour and texture throughout the bloom.

Flowering Shrub exhibits should show an evenness of flowers throughout the branch. Terminology is important. If the schedule calls for a branch of no more than 30", make sure that the branch is slightly less than 30".

Megan writes~
When is the best time to relocate peonies? I would like to move some from one side of my house to the opposite and I live in Dayton Ohio, so wanted to know if spring or fall is better. Please advise.

A. Some perennials are rarely divided or moved unless absolutely necessary. These include gas plants, peonies, tree peonies, foxtail lilies, goatsbeards, butterfly weeds and bleeding hearts. Most perennials decline with age and should be divided every 3 or 4 years. New growth can be noticed on the outer edges of clumps. Divide perennials when you notice the following:

a dead center formed in the crown area with a ring of growth around it;
blooms becoming sparse and smaller;
plants looking obviously crowded.

Do not divide perennials when they are in bloom. Divide spring-blooming perennials in late August or September. Usually gardeners relocate peonies in the first two weeks of October. Dig overgrown peony clumps with a shovel and cut them in half. Handle with care so the "eyes" or buds at the base of the plants aren't damaged. Plant so the eyes are 1-1/2 to 2" below the soil surface. If planted too deeply, they won't flower. Keep at least 3 to 5 buds per division. Do not hesitate to cut through a large clump of roots with a sharp clean ax. Most peonies can be left for many years (10 or more) without the need to divide.

Assistance from: Ohio State University

Megan writes~
I have some peonies on the side of my house and want to relocate to another place so that I can plant grass where they are now. I live in Dayton, OH and would like to know when would be the best time to relocate them. Please advise with what information you can.

A. Peonies can be left undisturbed for many years. Sometimes, however, it becomes necessary to move established plants. Peonies shaded by large trees or shrubs bloom poorly and should be moved to a sunny site. Large, old plants may become overcrowded and flower poorly. Large, old plants should be dug, divided, and transplanted to improve performance. The best time to move and divide peonies is September.

Moving established plants is a simple procedure. Cut the peony stems near ground level in September. Then carefully dig around and under each plant. Try to retain as much of the root system as possible. Promptly plant the peony in a sunny, well-drained site.

Division of large peony clumps requires a few additional steps. After digging up the plant, gently shake the clump to remove loose soil from the root system. Divide the clump into sections, making sure each division has at least 3 to 5 eyes [buds] and a good portion of the root system. Peonies grow best in full sun and well-drained soils. Dig a hole large enough for the entire root system. Place the peony plant in the hole so the eyes are 1-2" below the soil surface. [Note: peonies planted deeper than 2" often fail to bloom satisfactorily.] Fill the hole with soil, firming the soil as you backfill, then water thoroughly. Space plants about 3-4' apart. Apply a 2-4" layer of mulch in late fall. Straw is an excellent mulch. Mulching will prevent repeated freezing and thawing of the soil that could damage the plants. Remove the mulch in early spring before growth begins. Transplanted peonies will not bloom well the first spring. They should be back to full flower production by the third or fourth year.

Dept. Horticulture, Iowa State University