Peonies are cool-weather-loving plants that bear their bright, decorative blooms best in cool growing zones. These shrubs grow best in U.S. Department of Agriculture zones 3 through 8, and thrive in Denver’s zone 6. Peonies require specific planting times for successful establishment, and do best with regular care and maintenance. Choose the right garden spot for your peony, and start your planting based on Denver’s frost dates.
- Moderately Easy
Things You’ll Need
- Garden fork
- Organic compost
- Plant peonies in fall to give them a winter of rest and establishment. Peonies won’t thrive with spring plantings, especially in warmer areas like Denver. Plant the peony in mid September, just before Denver’s first frost.
- Put the peony in a spot where it gets indirect or filtered sunshine, or morning sun and afternoon shade. Peonies don’t appreciate full, bright light, but fail in too much shade. Make sure the site has good year-round drainage and 3 to 4 feet of growing space.
- Dig into the top 12 inches of soil to loosen the base, and add 5 inches of organic compost to give the peony good nutrition and drainage. The compost will maintain moisture to keep the peony from drying out in Denver’s arid summers.
- Plant peony root stock deeply enough to cover all the buds, or growing joints, with 1 to 2 inches of soil. Peonies fail in deep or shallow plantings. Pack amended soil firmly around the roots to complete the planting.
- Water the peony with 1/2 gallon of water to settle the soil, and put it on a schedule of 2 to 3 inches of water every week. Mulch the site with 2 inches of organic compost to keep the soil warm during winter, and cool and moist during summer. Add more mulch as the layer breaks down.
Tips & Warnings
Peonies take up to three years to bloom after planting.
Prune peonies in fall, after they bloom, to shape the plants and encourage healthy new spring growth.
Peonies may crowd out their growing site as they propagate at the roots. If your peonies stop growing or blooming, dig them up in fall and divide them at the roots.