How to Grow and Care for Purple Leaf Plum

The purple leaf plum tree (Prunus cerasifera), also known as the cherry plum, is popular in landscaping due to its ornamental nature. It’s a relatively small tree that has a rounded, spreading growth habit almost like a shrub. It produces fragrant, five-petaled pale pink to white flowers in the spring that are roughly an inch across, which then turn to small fruits. The elliptical leaves can range in color from purple to green. This tree has a moderate growth rate and gains about one to two feet per year. It’s best planted in the early spring or fall.

The stems, leaves, and seeds contain cyanide and are toxic, especially in the process of wilting; they are toxic to humans, and toxic to dogs, cats, and horses.

Purple Leaf Plum Care

The purple leaf plum is a relatively short-lived tree, lasting only around 20 years, and it requires a bit of maintenance. Yet growers still love it for its beautiful spring flowers and rich leaf coloring. 

In terms of its care, plan to water your tree throughout the growing season (spring to fall) if you don’t have sufficient rainfall. This tree also will likely benefit from annual feeding and pruning. Moreover, this is a messy tree. Be prepared to clean up the masses of fallen fruit that drop from the tree. It’s best to plant this tree away from walkways and other sites in your yard that get a lot of foot traffic, so you’re not walking on the fruit. But even so, wildlife will scatter the fruit about as they eat it.

Light

This tree grows best in full sun to partial shade. Ample sunlight causes the tree to produce its best purple leaf color. Otherwise, if it’s in a location that’s too shady, the leaves can become green.

Soil

The purple leaf plum likes loamy soil that has excellent drainage and an acidic to neutral soil pH (5.0 to 7.0). It also can tolerate clay and sandy soil. But it doesn’t like compacted soil or pollution and will struggle to grow in urban conditions. 

Water

This tree prefers a moderate amount of soil moisture. Once it’s established it does have some drought tolerance. But it likely will need watering during long stretches without rainfall or in extreme summer heat.

Temperature and Humidity

The purple leaf plum is fairly tolerant both to cold and to heat. It’s hardy down to minus 20 degrees Fahrenheit and can handle the high summer temperatures within its growing zones as long as it’s adequately watered. Humidity also is typically not an issue for the tree.

Fertilizer

This tree likes moderately rich soil. Fertilize annually in the spring as new growth begins with an all-purpose fertilizer. For the amount to use, follow the product label instructions. If you have rich garden soil, you might be able to get away with fertilizing only every two to three years. Your tree also can benefit from some compost worked into its soil in the spring.

Types of Purple Leaf Plum

There are several varieties of Prunus cerasifera, including:

• Prunus cerasifera ‘Thundercloud’: This variety features deep reddish-purple leaves. 
• Prunus cerasifera ‘Krauter Vesuvius’: This variety looks similar to ‘Thundercloud’ but has even darker spring foliage and grows slightly smaller.
• Prunus cerasifera ‘Newport’: The leaves on this tree are a bronze-purple in the spring, deep purple in the summer, and reddish-purple in the fall.
• Prunus cerasifera ‘Nigra’: This tree has bronze leaves in the spring, very dark purple leaves in the summer, and orange-red leaves in the fall. 
• Prunus cerasifera ‘Purple Pony’: This is a dwarf variety that only reaches around 10 to 12 feet in height and spread. 

Pruning

Purple leaf plum doesn’t need an excessive amount of pruning each year. Simply prune to maintain your desired shape for the tree, and remove any dead, damaged, or diseased branches. Prune after the tree has flowered, or you might accidentally remove flower buds.

Propagating Purple Leaf Plum

If you have the patience, rather than buying a sapling or young tree from a nursery, you can propagate purple leaf plum from softwood cuttings:

1. In the spring when the first flower buds appear, cut a shoot about 1/8 inch in diameter and 6 inches long with a sharp, clean knife. Remove all leaves except for the top three or four.
2. Dip the cut end in rooting hormone and plant it in a 4-inch pot filled with damp potting mix. 
3. Keep the cutting in indirect light outdoors and water it regularly. New growth is a sign that roots are forming.
4. Before planting it in your hard, let the potted sapling grow for a couple of seasons, transplanting it to a larger pot if necessary. The stronger the sapling when you transplant it, the better its chance of survival in the landscape.

As most purple leaf plums are cultivars, growing them from seed is not recommended, as it won't produce a tree true to type.

Potting and Repotting

Purple leaf plum is a tall tree that is meant to be planted in the landscape and not suitable for growing in containers.

Overwintering

Purple leaf plum is hardy to USDA zone 5 and does not require winter protection.

Common Pests & Plant Diseases

This tree is prone to several pests and diseases. Insects that might infest the tree include Japanese beetles, mealybugs, borers, tent caterpillars, and scales.

Common diseases include leaf spot, gray mold, black knot, and cankers. Symptoms of pests and diseases include discolored, wilted, or otherwise damaged foliage, along with poor growth and flowering.

Ensuring proper growing conditions and good airflow among the branches can help to prevent many problems.

How to Get Purple Leaf Plum to Bloom

If your tree isn't blooming, it could be due to a cold snap after unseasonably warm weather in the late winter or early spring, which damages the buds. Another possibility is improper pruning in the spring when you accidentally removed the flower buds. To ensure your tree blooms next year, only prune it in the fall.