How to Grow Peonies Indoors
Peonies are typically grown outdoors, but can make good container plants and placed indoors. Peonies are best planted as tubers or small plants in the fall so they can become established during the winter months. However, they can also be planted in the spring, if necessary. When buying peonies, consider that some grow so large they need support and in general, tree peonies have smaller root systems so they might be easier to grow in containers.
Choose a container with drainage holes that can accommodate the peony's roots, and has room to double or triple in size. The container should be heavy (e.g., clay) so that it won’t tip over as the peony gets larger and larger. If you plan to place the peony outdoors during the summer, select a light cover container so it doesn't heat up in the sun too much.
Fill the pot about 2/3 of the way with potting soil that is also mixed with plant fertilizer. Then dig a hole that is large enough to for the roots to fit. Plant the eyes—where the plant sprouts from the underground root stem—2 inches beneath the soil.
Backfill the soil around the root and water the plant until the water comes out the drainage holes on the bottom of the planting pot. Always dump the drained water out so the container is not sitting in water. Continue to water the peony in the same manner when the top 1 to 2 inches of soil dries out.
Place the container in near freezing conditions (e.g., unheated garage or attic) from late fall until late winter. Peonies need a cold dormancy to thrive. During this time, water only when the soil dries out completely (test with finger).
Peonies Won't Grow
A peony grown from seed will not produce flowers until it is at least 5 years old, and sometimes it takes up to 7 years for a peony to bloom, according to the North Dakota State University Extension Service. For that reason, many home gardeners purchase and plant older peonies. This is because they get crowded. In these cases, dividing the plant should help, but keep in mind that newly divided peonies don't usually bloom the first year after being transplanted. If they are in shade for most of the day, they won't grow or bloom very well, if at all. Dilute the fungicide with water at a ratio of 4 ounces for every 25 gallons of water. To help prevent Botrytis blight and other fungal diseases, water at the level of the soil, keeping the foliage as dry as possible. This is a fungal disease, caused by wet, saturated soil, that destroys the roots of the plant.
- Potting soil
- University of Illinois Extension: Time to Enjoy Peonies
- Ohio State University Extension Fact Sheet: Growing Peonies
- North Dakota State University Extension Service: Questions On Peony
- The Old Farmer's Almanac: Peonies
- Heartland Peony Society: Frequently Asked Questions
- University of California IPM Online: Peony (Paeonia spp.)
- University of California IPM Online: Gray Mold Pathogen -- Botrytis cinerea