Growing beautiful peonies
It would be hard to find an easier plant to grow than peonies. Some plants have been known to live for 50 years or more with little care. Even so, if you want to grow peonies, you'll want to get the best performance they can give.
How to shop for peonies
In spring you'll find potted peonies in garden centers. While the selection is usually pretty limited you can get them in the ground as soon as you get them home. Mail-order nurseries have enough cultivars to make your head spin, and these usually come bare-root in the fall and look like the one in the photo below. You can plant them anytime before the ground freezes.
According to Roy Klehm, retired nursery owner and long-time peony breeder, before you order, ask how many eyes the plant has (eyes are the pink buds sprouting on the roots). Getting one with at least three to five eyes is the optimum size for a peony to adapt to new situations. Plants may flower the first spring but those blooms are usually small. They’ll become full sized in about three years.
Get your peony growing right
Peonies do best with full sun and well-drained soil. There's no need to fertilize much, either. A low-nitrogen formula, such as 10-15-10, every other year in spring, or an annual application of compost is just fine.
Planting depth is key to growing great peonies
Where winter temperatures dip below zero, the base of the eyes should be about 2 inches deep as the illustration above shows. In zones 7 and warmer, you might want to plant them just ½ inch below the soil. This lets roots stay cooler in winter and starts them blooming sooner in spring before the weather gets hot.
Stake peonies early
Peony stems are sturdy, but the blooms are sometimes heavy enough that the plants flop. Staking can help keep the flowers out of the mud and up where you can enjoy them. Remember to install your stakes in early spring as the foliage is just emerging. Trust me, trying to prop up an armload of heavy peony foliage later doesn't work.
Hoop stakes are an easy solution. The nice thing about these is that they're easily covered by the foliage and the stems still move around a bit so the natural form of the plant remains. Just make sure the rings are tall enough to hold the stems upright. If the hoop is too short, the flowers will flop over the top ring and might snap off.
DIY peony stakes
You can also make our own peony staking system. Place four stakes in a square, then connect and crisscross them with string when the shoots emerge in spring. As the plant grows, you'll need to make sure the stems stay inside the stakes and between the strings.
Cut peony flowers
Set at the right depth, mature peonies will produce plenty of blooms to keep the garden pretty and your vase full. They make a great cut flower. Cut them first thing in the morning while plants are still hydrated and choose buds that look full and feel spongy - too tight and they won't open. That way you can watch your flowers open and enjoy the lush blooms for about a week, depending on the weather. The warmer it is the faster the flowers open and fade, keep them cool and they'll last longer.
If a late frost is expected or you want to extend the enjoyment of your peony blooms you can save them for later. Deadheading will tidy up the plant so the foliage becomes be a nice border accent or backdrop for later blooming perennials.
Folklore holds that peonies need ants to help them open, but ants neither hurt nor help. They are just eating the sap from buds.
What’s wrong with my peony?
Peonies are pest- and disease-resistant but there a couple of common fungal diseases - botrytis and phytopthora - that can crop up. These fungi thrive in the cool, rainy weather and have symptoms so similiar that it’s hard to tell which is which. Fortunately, the treatment is the same. If you see dark spots on your peonies like those above, you can bet they’ll start small and spread to cover the whole leaf surface. It may even infect buds so that they shrivel up and fail to bloom. Botrytis or phytopthora don’t usually kill plants but they’ll return year after year without some intervention from you. Here’s what you can do:
5 things you can do to help your peonies avoid or fight off fungal infections:
- Don’t water overhead. Watering at soil level prevents spores from being splashed onto the stems.
- Allow space between plants for good air circulation.
- Keep an eye on your peonies, especially in spring, and if you notice signs of infection, prune the affected stem down to the ground.
- Clean up in the fall. Getting rid of spent foliage in fall is a must. Burn or throw away any debris, as this fungus can survive in compost piles.
- If things get really bad, try using a fungicide with neem, such as Garden Safe Fungicide 3. It can be used as a preventative, and also after the infection has started.
Get more peonies
Though peonies don’t need division to stay healthy, you may want to add another plant to your border or share with a friend. It's best to divide peonies in fall as temperatures starting to cool. You can dig the whole plant and it will likely just fall into pieces. Or choose two or three stems on the edge of a clump and slice down with your shovel to separate them from the rest of the plant. Next pry them up and cut the stems off at the base. Replant them in the same way you plant a bare root peony. That way the plant you’re taking the piece of still looks full and blooms vigorously the following spring.
Mature peonies are super cold-hardy, but you can help your new plants along with 3 to 4 inches of organic mulch in late fall. In spring, pull the material away to make way for the new growth.
Growing peonies in the South
Gardeners in USDA zones 7 and warmer have always struggled to grow these beauties because the roots need a cold period in winter and the flowers don’t do well in heat and humidity. I already told you how shallow planting can help with this.
Here are three more tips for growing peonies in the south:
- Choose early blooming cultivars so the flowers open before the heat really gets going.
- Choose single or anemone flower forms because they have fewer fungal problems.
- Give your plants some afternoon shade to keep them cool.