Flowers & Landscaping
How to Grow Peonies
Peonies are long-lived, easy-care, colorful spring-blooming perennials. What's not to love? Here's how to grow them in your own garden.
You know that summer is finally on the way when the peonies bloom. These gorgeous perennials burst into bloom in the weeks around Memorial Day, when spring bulb flowers are winding down and summer flowers are starting to grow. Peonies are deer- and rabbit-resistant, which makes them handy for gardeners who routinely have problems with animals munching on their plants. If you drive by old cemeteries or abandoned farmsteads, you’ll often see peonies blooming away, having received little care for many years. That’s because peonies are easy to grow!
Here’s how to grow peonies.
How to Choose Peonies
There are four types of peonies. They are, in order of bloom time: woodland peonies, tree peonies, herbaceous peonies, and intersectional peonies. The two most common types are herbaceous peonies, which grow well in zones 3-7, and tree peonies, which grow in zones 3-9. Herbaceous types usually grow to a height of 2 to 3 feet and a spread of 2 to 4 feet. Tree peonies are more like small shrubs, with some varieties topping out at 7 feet. All types of peonies require similar care, so the choice of what to plant depends on where you live and the look you’re going for. This article will focus on herbaceous and tree peonies.
When to Plant Peonies
The best time to plant peonies is in the fall. If you order peonies from a catalog, this is usually when they’ll be shipped. Sometimes you’ll find container-grown peonies blooming and for sale in the spring, and it’s fine to plant them then.
Where to Plant Peonies
Peonies need at least 6 to 8 hours of sun each day, though some protection from hot afternoon sun in zones 8-9 is helpful. Choosing an area with good air circulation is essential as well, to help prevent fungal diseases.
How to Plant Peonies
Peonies grow best in slightly moist, well-drained soil. To plant container-grown herbaceous peonies (the kind you buy in pots), dig a hole, remove the plant from the pot, and put it in the hole so that the top of the root ball is level with the soil (any deeper and the peonies will not bloom). Blend the soil you’ve removed with an equal portion of Miracle-Gro® Garden Soil for Flowers then fill in around the plant.
With bare root herbaceous peonies, first soak them in a bucket of water for a few hours to rehydrate them before planting. Dig a hole large enough to accommodate the roots, blend the soil as described above, and create a mound of blended soil in the center of the planting hole. Position the roots on top of the mound, allowing them to fan out and down. Fill in the rest of the hole with the remaining blended soil, making sure that the “eyes” (or growth buds) of the plant are covered by no more than 1 to 2 inches of soil (otherwise, they won’t bloom).
Tree peonies need to be planted deeper. Unless they are grafted, plant peonies so that the crown (where the roots meet the stem) is 2 to 4 inches deep, using the same soil mixture as described above. If the plant has been grafted (check the label), plant it so that the “graft union” (the part of the plant where the grafted top is joined to the rootstock) is 4 to 6 inches below the soil line.
Be sure to water thoroughly after planting.
How to Stake Peonies
Peony blooms can grow to be large and heavy, and stems are prone to flopping over after it rains. The best solution for herbaceous peonies is to place a peony cage (imagine metal supports with rings for the flowers to grow up through) over each plant in the spring before the leaves start to emerge. This is much more efficient than trying to support each individual flower stem, and more attractive than tying a piece of twine around the whole plant and cinching it like a belt.
Tree peonies can be staked with a single stake. Drive the stake into the ground next to the stem and tie the plant loosely to the stake with a piece of twine.
How to Water Peonies
Water thoroughly at the time of planting. Water the plants again when the foliage starts to emerge in the spring, and once more when the flower buds appear. Peonies are not thirsty plants, but will benefit from being watered during dry periods for a year after the initial planting.
How to Feed Peonies
Great soil plus just the right plant food equals a powerful care combination for your peonies. In addition to making he soil improvements mentioned above, give peonies the nutrition they need by feeding them with Miracle-Gro® Shake ’n Feed® Rose & Bloom Plant Food for gorgeous color and more blooms vs. unfed plants. Peonies should be fed twice a year, once after they emerge in the spring (after the new shoots reach 2 to 3 inches tall but before the flower buds become pea-sized), then again midway through the growing season (about 3 months after the first feeding) to build strong roots before winter comes. Be sure to follow label directions.
How to Help Prevent Problems with Peonies
Peonies are relatively fuss-free, but can sometimes suffer from fungal problems. Botrytis causes flower buds to turn brown and fail to open. Some fungal diseases manifest as brown spots on leaves. The best way to control these issues is to simply prune off and throw away (do not compost) infected flowers and leaves. In addition, keep the plants tidy, deadhead spent blooms, and remove old growth at the end of the season. Ants are sometimes attracted to peony blooms, but they will not harm the plants, so you can just leave them alone. (Contrary to the old wives’ tale, peonies do not need ants in order to bloom!)
How to Prune Peonies
Once all of the blooms on herbaceous peonies have faded, cut back each flower stalks to just above a leaf, low enough that the stem doesn’t stick out of the rest of the foliage. You can prune tree peonies that have grown unruly in either the spring or the fall (right before plants go dormant). If you prune in the fall, though, any stalks you cut back will not bloom the following spring (as you will be cutting off the flower buds). In the springtime, you can prune right after blooming. Whenever you choose prune, be careful not to remove more than 1/3 of the plant.
How to Divide Peonies
Tree peonies are best left alone (undivided) to grow for generations in the garden. Herbaceous peonies can be divided if the clumps have spread too far or blooming has slowed. To divide herbaceous peonies, dig up the entire clump and hose it off so that you can see the various roots and eyes (or buds) of the plant. Use sharp, clean pruners to cut apart the plant, leaving at least one large root and 3 to 4 eyes per clump. Replant, following the instructions above for planting bare root peonies. Keep in mind that the plants may or may not bloom the first year after dividing.
How to Cut Peonies for Bouquets
Timing is key. Buds should be at the “soft marshmallow” stage, meaning if you squeeze an unopened bud, it should feel about as firm as a soft marshmallow. Another way to tell when to cut is to look at the coloring on the buds. Most of the outside of the bud should be green, but you should be able to see about 1/2 inch of colorful petals peeking through. Cutting at this stage reduces the chance of bringing ants inside with the flowers, but it’s still wise to check the flowers before taking them into the house. Place stems in a vase of water and allow plants to open. Change the water every few days, and add Miracle-Gro® for Fresh Cut Flowers so the blooms will last longer (vs. water only).
How to Grow Peonies: Recap
- Choose peonies that will grow well in your garden conditions.
- Plant peonies in full sun in the fall or spring.
- Prepare the soil by adding Miracle-Gro® Garden Soil for Flowers.
- Water plants thoroughly, then occasionally through the season.
- Support plants with peony cages.
- Feed plants with Miracle-Gro® Shake ’n Feed® Rose & Bloom Plant Food.
- Deadhead to keep plants tidy and prune as necessary (herbaceous only).
- Divide peonies when plants become overcrowded and have fewer blooms.
- Cut stems for bouquets when buds feel like soft marshmallows. Add Miracle-Gro® for Fresh Cut Flowers to water.
Ready to start growing peonies? Click on any of the product links above for more information, to purchase the product online, or to find a retailer near you.