Herbaceous Peony Culture and Care
Garden Peonies, the Queen Flowers of Spring
Herbaceous Peonies are one of the most easily grown hardy perennials available today. Long lived and durable, a peony can live easily as long as 100+ years. The most common peonies in this group were selectively bred plants originating from the species Paeonia lactiflora, which is native to China. Other species have been hybridized with P. lactiflora to create herbaceous hybrid peonies. The hybrids are often more upright plants with larger, more vibrantly colored flowers. Both lactifloras and the hybrids are grown in the same way, have similar plant habits and needs. Typically, herbaceous peonies do not require much special treatment and their culture is fairly intuitive for the gardener, with some exceptions.
For more detailed information please use our Herbaceous Peony Culture and Care document.
-Major Points of Culture-
- Plant in a well-drained site, which never becomes wet and allows roots to prosper. It is especially important to know the winter season’s site properties, as this is period in which many soils may become saturated. Typically, gardeners do not notice winter soil conditions due to inactivity in the garden, thus extra attention is required to the site before planting. Winter kill from excessive moisture is one of the most common reasons for herbaceous peony crown death (rotting).
- Plant in a well-drained site, which never becomes wet and allows roots to prosper. It is especially important to know the winter season’s site properties, as this is period in which many soils
- Select a site which does not have competition from other plants – especially shrubs and trees. Lilacs and some other shrubs produce root systems which compete with the roots of peonies for the same nutrients.
- The planting site should be one not subject to late spring frosts, as this may prevent young buds from developing further. Low sites are most often impacted by late frosts.
- Provide a site with full sun or very light shade. Those planted in hot summer climates are best when some shade is provided to protect the leaves from burning.
- Water only if needed. Herbaceous peonies are quite drought resistant and resent wet feet. Keep plantings well clear of automatic sprinklers, such as those to keep lawns green and growing. Do not plant near downspouts and roof driplines.
- Provide a site which will have good air movement and is not crowded. Good air movement around plants prevents foliar and stem diseases.
- Plant in predominately native soil found at your location, if at all possible. Amending soils heavily with organic material in the planting hole often creates a ‘BIRD BATH EFFECT’, in which water is held and may cause rooting issues. The goal is to create a homogenous soil in which roots do not encounter pockets of variable constituents (roots have to adapt to each soil variable they encounter). If amending the soil, do so broadly over the entire planting area, not just the planting hole. DO NOT USE excessive amounts of peat as an amendment – it holds water and is acidic. Peat is a very good dry packing material for shipping peonies due to its antiseptic properties, but is not useful as a major soil constituent for growing peonies. However, peat may be well mixed with native soils in very minor amounts to improve soil structure without detriment.
- Soils which support best growth have a near neutral pH (6 to 7). Clay soils are often highly fertile and may support excellent growth, but may hold excessive water which damages roots. Avoid soils with fresh and excessive organic material included, as this may promote disease. Soils predominantly composed of sand are not particularly fertile and peonies will not prosper.
- Cut stems to the ground after the growing season has ended in the fall season. Remove all stems and leaves from the garden and destroy or send to a public composting program. Do not compost foliage from peonies for use in future peony plantings, as residual diseases may persist and infect plants where applied. Do not cut down herbaceous peonies while foliage is green, since they continue to use their leaves to photosynthesize (make energy).
- Containerized culture is not recommended and less than positive results may be expected over time. Plant herbaceous peonies in the ground where they may grow their extensive root systems.
- Fertilize only if necessary. Allow plants to establish at least 3 years before considering the application of fertilizer (true for all peonies). Avoid the use of fresh manure, as this may burn root systems or carry diseases. Herbaceous peonies grow slowly the first couple of years and their growth is always measured, thus it is unlikely any large increase in growth will ever be noted after fertilizing. High nitrogen fertilizers, as those found in lawn and bedding plant ratios, are to be avoided. High nitrogen fertilizers will promote soft growth susceptible to disease.
- Plant them in the late summer into the fall season as soils begin to cool. This period of time is when root growth occurs. The month of planting will depend upon the region in which the garden is located. Those in the northern tier of the United States usually plant at the end of September to mid-October. More southerly locations will have best results in mid-October to November. Spring planted divisions can be expected to flounder (or die) and will not produce roots until soils begin cooling in late summer – spring planting is not recommended and does not produce a larger plant the following year.
- Avoid the use of mulch near herbaceous peonies. Mulch often holds excessive moisture and does not allow for good aeration of the soil below it, often creating a wet situation. Mulching plantings has become popular and is one of the main causes related to plant failure and development of disease. If plantings are mulched, make sure it is applied no closer to the peony plant than 16 inches. Additionally, many of the commonly available mulches are now treated with preservatives and coloring to enhance their longevity and visual appeal, these may be detrimental peony growth. Mulch contamination from oils, herbicides and other contaminants may occur at the production site before it is sold to end consumer – these may also present issues with its use. Lastly, some wood mulches may be produced from tree species which contain chemicals which adversely impact peony growth (ex: Black Walnut).