Peonies come in three main types: herbaceous, tree, and intersectional (Itoh). Herbaceous peonies die back in winter and regrow in spring, while tree peonies have woody stems that persist year-round. Itoh peonies are hybrids of the two. For maximum blooms, select a variety suited to your climate. Herbaceous peonies thrive in colder regions, while tree peonies prefer milder winters. Ensure the variety you choose has a reputation for prolific blooming, such as 'Sarah Bernhardt' (herbaceous) or 'High Noon' (tree).
Peonies demand full sun (at least 6 hours daily) to produce abundant blooms. In hotter climates, partial afternoon shade can prevent scorching. The planting site should have well-draining soil, as waterlogged roots lead to rot and fewer flowers. Avoid planting near large trees or shrubs that compete for nutrients and moisture. Peonies also prefer slightly acidic to neutral soil (pH 6.5–7.0) rich in organic matter.
Before planting, amend the soil with compost or well-rotted manure to improve fertility and drainage. Dig a hole 12–18 inches wide and deep, loosening the soil at the bottom to encourage root growth. Avoid adding excessive fertilizer, especially high-nitrogen formulas, which promote foliage at the expense of blooms. A balanced, slow-release fertilizer or bone meal can be mixed into the planting hole for sustained nutrition.
Planting depth is critical for peonies. Herbaceous peonies should be planted with their "eyes" (buds) no more than 2 inches below the soil surface. Tree peonies require a deeper hole, with the graft union (if present) 4–6 inches below ground. Planting too deep prevents blooming, as the buds struggle to reach sunlight. Ensure roots are spread out horizontally in the hole and backfill gently to avoid air pockets.
Water newly planted peonies thoroughly to settle the soil. After establishment, peonies are drought-tolerant but benefit from consistent moisture during bud formation in spring. Avoid overhead watering to prevent fungal diseases. Mulch with 2–3 inches of organic material (e.g., straw or bark) to retain moisture and regulate soil temperature, but keep mulch away from stems to prevent rot.
Large peony flowers can weigh down stems, especially after rain. Install peony rings or stakes early in the growing season to support the plant. This prevents stems from bending or breaking, ensuring blooms remain upright and visible. For tree peonies, prune lightly to maintain a sturdy structure.
Peonies need space for air circulation to prevent diseases like botrytis. Space herbaceous peonies 3–4 feet apart and tree peonies 4–5 feet apart. Divide overcrowded clumps every 10–15 years in fall to rejuvenate blooming. Replant divisions at the proper depth in fresh soil.
Peonies dislike being moved and may take 2–3 years to bloom after transplanting. Choose a permanent location and avoid unnecessary digging around the roots. If you must move a peony, do so in fall when the plant is dormant.
Remove faded flowers promptly to redirect energy into root and bud development for the next season. For herbaceous peonies, cut stems back to just above a healthy leaf. Avoid cutting tree peony stems unless necessary, as they bloom on old wood.
