Cultural Information

Once established, a peony is a low maintenance plant that requires only basic care. Their growing requirements are as follows:

Exposure – In northern climates such as Montana, peonies prefer full sun. Site them where they can receive a minimum of six hours of direct sunlight daily during their active growing season (typically May through mid-September). Note, however, their blooms will last longer when the plant is not stressed by high heat such as placement against a cement wall on the south side of a house.

Disease control – Peonies in Montana are not generally at risk for many diseases. Botryis is one common fungal disease that may affect peonies, particularly during wet, cool spring weather. In small gardens simple measures such as removing stems after fall dormancy and disposing of them will prevent botrytis from gaining a foothold. There are however, organic sprays with a copper base or a beneficial bacterial component (i.e., Actinovate) that can help prevent severe problems.

Fertility – Peonies will respond to a soil that has a balanced level of macronutrients (nitrogen, phosphorous, and potash) and a good micronutrient profile. Usually, a balanced slow-release fertilizer once in the spring is sufficient to keep peonies healthy and blooming well. A high nitrogen fertilizer is not recommended.

Mulch and compost – Peonies do not need to be mulched in winter to protect them. A summer mulch is also not necessary. Digging in a good grade of compost around the crown each spring, however, can be beneficial

Soil Types – Peonies are adaptable to different soil types but definitely prefer to be in a site that is well-drained. The roots may rot or be more susceptible to fungal disease if they sit in saturated soil over long periods of time. Generally peonies will grow well in a soil pH in a range from 6.5 to 7.5.

Spacing – For proper air circulation, peonies should be planted at least three feet apart.

Watering – Peonies in Montana will require watering. Their preference is to be watered deeply as needed and then allowed to dry out somewhat. They do not like to be overwatered. They will grow okay under a daily automated lawn watering system but that is not their preference.

Weed control – Though peonies have deep roots and can stand some weed competition, as is the case with most plants, they benefit by keeping perennial grasses and weeds under control. They will definitely be more productive and probably longer lived if they are maintained in such a manner.