What is the best way to store peony bulbs this winter and plant them in the spring?
Question:
I bought lots of peony bulbs in late fall and will plant them this spring. They are now covered in potting soil in pots in my garage. What’s the best way to plant to ensure they do well?
Answer:
Typically, peonies are planted in the fall to allow them to establish roots before winter, but that isn’t always possible for various reasons, so we move on to spring planting, where we largely treat them as any other bulb going in. They should go in as soon as the soil has thawed (no chipping at frozen ground) and drained a bit (if things are still sodden and muddy, the bulbs can rot). Herbaceous peonies should have at least 3′ of space between each to accommodate the root and canopy spread at maturity, and in full sun (a bit of shade is ok, but they should be getting 6-8 hours of direct light every day).
The spot should be moist and well-drained (if it’s clay-y or overly sandy, you may need to add compost or well-aged manure), with a pH of neutral to slightly alkaline–I recommend getting the soil tested through the UMaine Soil Analytic Lab before putting them in (or, since you’re trying to get them in early, as soon as possible after the soil is workable) to see if you need pH-raising amendments in the location. You can pick up a test kit for free in any Extension office, or request that the lab mail you one. Instructions for obtaining the sample are found here. The lab will not only let you know the nutrient composition and pH, but will also make recommendations for anything that needs to be added or avoided this season from a fertilizer perspective.
It’s recommended that the holes for the bulbs be worked a bit wider than normal so that the roots have good, loose, high quality soil to push their initial growth into, and the bulbs should be planted relatively shallow. Anything deeper than 2″ is likely to reduce blooming. Consistent watering through the spring and summer, and a light mulch with wood chips to maintain soil moisture and suppress weeds are great ideas.
Because you’re putting these in during spring, keep an eye on the weather. If it looks like we’re in for an unexpectedly late hard frost, I would put a blanket of straw or shredded bark mulch over the plantings to protect them until things warm back up.
There are a couple more resources you might find helpful:
Univ of IL Extension quick guide to Peony
Univ of WI Extension full guide to Peony
Happy gardening.