Purple Leaf Sand Cherry (Prunus × cistena)

Plum leaf sand cherry, also referred to as purple leaf sand cherry plants, is a medium sized ornamental shrub or small tree that when mature reaches a height of approximately 8 feet (2.5 m.) tall by 8 feet (2.5 m.) wide. This easy care plant makes a great addition to the landscape.

I. Appearance and Characteristics

Prunus × cistena, the purple leaf sand cherry or dwarf red-leaf plum, is a hybrid species of Prunus, the result of a cross between Prunus cerasifera (cherry plum or myrobalan plum) and Prunus pumila (sand cherry). A deciduous leggy bush or shrubby tree, it typically reaches a height of 1.5–2.5 meters (5–8 ft) and has a useful life of 10–20 years. The fruits are edible, if strong-tasting. Some people make jams or preserves from them. It is not advisable to eat the pits.

Frost-tolerant, purple leaf sand cherries can be grown up to USDA Hardiness Zone 2a. Commercial specimens are typically grafted to a rootstock from any of a number of other species, which will influence their growth form and final height. There are also a limited selection of cultivars available.

Prunus × cistena was developed by Niels Ebbesen Hansen in 1910. In 1993 it won the Royal Horticultural Society’s Award of Garden Merit.

II. How to Grow and Care

Sunlight

Choose a planting site that receives full sun, as the foliage color will be more vibrant with adequate sunlight. Tolerates part shade, but best flower production and leaf color are obtained in full sun. Ensure that the location provides well-draining soil to prevent root rot.

Temperature and Humidity

This plant is pretty much all-weather hardy, able to withstand a wide variety of temperatures through both summer and winter, though plants grown in consistently colder weather may be smaller and produce fewer blooms. It tolerates hot and humid summers.

Watering

The purple leaf sand cherry needs to be watered regularly and is not drought-tolerant. Typically, one watering per week will suffice, but more may be necessary if you’ve recently transplanted, are going through a period of hot, dry weather, or the plant is in its first season of growth.

Soil

Prunus cistena is adaptable to various soil types but prefers organically rich, well-draining, loamy soil. Amend the planting area with organic matter, such as compost or aged manure, to improve soil fertility and drainage.

Fertilizing

Apply a balanced, slow-release fertilizer in early spring to support healthy growth. Avoid over-fertilizing, which can lead to excessive foliage growth at the expense of flowering.

Planting Instructions

Dig a hole twice as wide and just as deep as the root ball of the plant. Gently loosen the roots, place the shrub in the hole, and backfill with soil, ensuring that the top of the root ball is level with the surrounding soil surface. Water thoroughly to settle the soil and eliminate air pockets.

Pruning

Pruning should be done after spring bloom to maintain a tighter oval shape or to create an ornamental hedge. Trim the oldest stems first, removing about a third of the existing growth.

Always remove dead, damaged, or diseased branches. To keep the shrub in its assigned space, cut off any suckers from the base of the plant.

Purple leaf sand cherry is mostly grown as a multi-stemmed dense shrub but can also be pruned into a small tree with a short trunk.

Propagation

Because purple leaf sand cherry is a hybrid, it cannot be propagated from seed. Instead, use one of the many suckers at the shrub’s base for propagation. Take these steps in the early summer:

• Dig out a few suckers using a trowel. Select the suckers with the most roots attached to them.
• Use a pot that is large enough to accommodate the roots of the sucker. Fill it halfway with potting mix.
• Place the sucker in the center of the pot and fill to the top with potting mix. Gently tamp down the soil around the stem. Water it well.
• Place the pot in a bright location but out of direct sunlight. Keep it evenly moist. Wait for at least one month, or until you see a good amount of new growth, before transplanting it into the landscape. Because of its shallow, spreading root system and size, a regular-size purple leaf sand cherry is not a good shrub for growing in a container.

Mulching

Apply a layer of organic mulch, such as shredded bark or wood chips, around the base of the plant to help conserve moisture, regulate soil temperature, and suppress weeds.

Pests and Diseases

Common Pests & Plant Diseases

Purple leaf sand cherry is a hardy plant but is highly susceptible to pests and diseases, which can shorten its lifespan to less than 10 years. Watch for Japanese beetles, which can do significant damage to its foliage. Other pests include the peach tree borer, scale, spider mites, aphids, leafhoppers, and tent caterpillars.

The shrub is also at risk for several diseases, including honey fungus, leaf curl, cankers, powdery mildew, leaf spot, and bacterial leaf scorch.

This plant is also somewhat affected by black knot, a common fungal disease that appears as black, corky swellings on branches that cut off nutrients to the tree.

Common Problems

As attractive as it is, purple leaf sand cherry has problems that often reduce its lifespan. Watch for these signs.

• Peeling, Oozing Stems

The stems of the purple leaf sand cherry tend to peel and ooze sap, a trait that is particularly noticeable if the plant develops fissures, cankers, or other wounds. Carefully remove and dispose of these damaged stems and branches to avoid spreading the problem.

• Branch Breakage

The purple leaf sand cherry’s branches are prone to some breakage from the black knot fungal disease. Prune out the black knot galls if possible to save branches. However, watch for frost cracks that lead to wood rot and breakage.4 The tree may heal itself before breaking. Or, wrap it for winter or trim away excess bark.5

• Dying Leaves

Keep an eye out for telltale signs of pests, such as lacy or hole-ridden leaves, and browning or withering foliage.

III. Uses and Benefits

Prunus cistena is often used as an ornamental shrub, providing visual interest and texture in mixed borders, hedges, or as a specimen plant. Its contrasting foliage makes it an excellent companion for plants with lighter-colored leaves or flowers.