Flowering Almond (Prunus glandulosa)

Chinese bush cherry is a popular ornamental tree grown in its natural form and numerous hybrid varieties. In its native East Asia, it is a host plant to the larvae of the eastern Tiger swallowtail butterfly (Papilio glaucus). All parts of the plant contain cyanide, which is toxic to humans when ingested. 

I. Appearance and Characteristics 

Prunus glandulosa, called Chinese bush cherry, Chinese plum, and dwarf flowering almond, is a species of shrub tree native to China and long present in Japan. It is commonly used as an ornamental tree and for cut flowers.

It has white or pink flowers – single or double varies with cultivar – that bloom in Spring. Fruits are dark red. Its height is about 1.5 meters (4.9 ft) and prefers rocky slopes with plenty of sun. Leaves are alternating, pointy, and light green. It is drought tolerant. It is susceptible to mice as well as these diseases: fire blight, leaf spot, die back, leaf curl, powdery mildew, root rot, and honey fungus.

Cultivars include: ‘Alba’ – (single white flowers), ‘Alba Plena’ (also ‘Alboplena’) – (double white flowers), ‘Lawrence’ – (single white-pink flowers), ‘Rosea Plena’ (also ‘Sinensis’) – (double pink flowers).

II. How to Grow and Care

Sunlight

Dwarf flowering almond does best in full sun to partial shade. Try to give it at least five hours of sun each day. In colder regions, it will appreciate even more sun.

Temperature and Humidity

Dwarf flowering almond grows well in a variety of climates in USDA zones 4 to 8. It requires only a short season of cool weather to prompt flowering in the spring. Dwarf flowering almonds are fairly tolerant of urban air conditions.

Watering

Water regularly to keep the soil moist but not wet, especially during the summer. Cover the soil with 2 inches of shredded mulch for extra protection.

Soil

Dwarf flowering almond is tolerant of a wide range of soil conditions, from sandy to clay, but excessively wet soil can be damaging. It does best in soil with average fertility and a fairly neutral pH level between 6.5 to 7.5, though it will tolerate soils that are slightly more acidic or alkaline.

Fertilizing

Fertilize this shrub with a layer compost spread over the root zone in spring. Otherwise, it does not need additional feeding if the soil is healthy. If you’re looking to promote extra root strength, you can use a phosphorus fertilizer.

Pruning

The most critical aspect of plant care for dwarf flowering almond is pruning. Dwarf flowering almond is a thin-stemmed plant that can sprawl and grow messy if left alone for too long. The best time to prune is just after blooming is over in spring. This can be done even before the branches have leafed out. This shrub flowers in spring on old wood created during the previous growing season, so pruning it too late removes the growth that makes next season’s flowers possible.

Proper pruning has several elements:

• Remove suckers that sprout up around the base of the plant—unless you wish for the shrub to spread and naturalize.
• Remove any dead or diseased stems down to ground-level
• Remove a few of the thickest, oldest stems down to ground level to stimulate new growth and more profuse flowering.
• Shorten any scraggly, sprawling stems to keep the shrub tidy and control its height.
• You will not hurt this shrub by giving it significant pruning—it’s better to prune too much than too little. If the shrub becomes too overgrown or sparse, it responds well to a vigorous rejuvenation pruning that cuts the entire shrub back to just above ground level. It may take a year or two, but the plant will eventually return to a healthy state.

Propagation

Dwarf flowering almond shrubs are species plants rather than grafted plants, so they reproduce reliably from new softwood cuttings in spring or early summer, or from semi-hardwood cuttings from July to August.4 Here’s how to do it:

• Clip a 6- to 12-inch segment of branch tip, using sharp pruners. Trim off the lower leaves, but leave at least two pairs of leaves at the top of the cutting.
• Scrap off about 1 inch of bark from all around the bottom of the cutting, using a sharp knife or the blade of a sharp pruner.
• Dip the bare end of the cutting in rooting hormone, then plant it in a pot filled with moistened potting mix.
• Place the planted cutting in a loosely secured plastic bag, then place it in a location with bright indirect light. Periodically check the potting mix and remoisten when necessary.
• In about six to eight weeks the cutting should develop roots (tug on the cutting; if you feel resistance, it means roots have formed).
• Once the cutting has rooted, move it outdoors and continue growing it for at least a full year in the pot. For winter months, move the potted sapling into a sheltered location (such as a cold frame) until spring.

Plant the shrub in the landscape when it begins to develop new growth the following spring.

How to Grow Dwarf Flowering Almond From Seeds

Seed propagation of dwarf flowering almond is not common, as the process can take three years or more. Seeds taken from the fruit of a dwarf flowering almond must go through two to three months of cold stratification—either stored outside or in a refrigerator for the winter—before they are planted. Once planted in a tray with moistened potting mix, the seeds can take as much as 18 months before they germinate and sprout.

When they are large enough to handle, individual seedlings can be transplanted into individual pots, then grown in a greenhouse or cold fame through the first winter. The following spring, the seedlings can be transplanted into the landscape

Potting and Repotting

Because dwarf flowering almond has a limited period of visual appeal, it is not often grown in containers on decks and patios. However, it is easy enough to do so, and it is sometimes the best strategy in landscapes where the garden soil is wet and poorly draining. By planting the shrub in a large pot or raised bed filled with a good porous potting mix, you can ensure soil conditions that are favorable to the plant.

Use a large ceramic or clay pot (at least 20 gallons) with a drainage hole. Some growers blend in some sand with a commercial potting mix to improve drainage.

Container culture is most common in milder climates, where a potted shrub can ornament a large patio or deck. In regions with very cold winters, potted almond shrubs should be moved to a sheltered location for the winter.

When a potted dwarf flowering almond fills its container and begins poking roots through the drainage hole, remove it, trim back the root mass by about one-third, then repot in the same container with additional fresh potting mix.

Overwintering

Within its hardiness range, dwarf flowering almond generally survives winter unharmed, but be sure to prepare it by watering well in the fall. Do not prune in winter, as this removes the growth that fuels spring flowering.

Pests and Diseases

Common Pests and Plant Diseases

Dwarf flowering almond is prone to an unfortunately large number of diseases and pests. Common diseases include leaf spot, powdery mildew, root rot, and honey fungus.

Verticillium wilt is a serious, usually deadly fungal enemy of this shrub. The disease causes leaves to curl up and branches to systematically die back, one by one. Verticillium is a root disease that causes the plant’s root system to constrict so that water can not move up the stems. Affected stems should be pruned away, but once the shrub is infected, it is often doomed to eventual removal. This fungal disease is more likely to occur in soil that does not drain well.

You can help prevent fungus disease and pests by raking up fallen leaves around the shrub, which can harbor fungal spores and insect eggs and larvae.

Common Problems 

Beyond the many diseases and pest problems that can plague dwarf flowering almond (see above), the most common complaint with this shrub is its rather dull and messy appearance once the dramatic early spring flowers have faded. This plant has limited appeal as a specimen shrub for all but a month or so of the year. Thus, it is best kept to the back of the landscape as part of a border screen.

Yellowing leaves on this plant usually is a sign of a mineral nutrient deficiency, such as a lack of nitrogen or iron. In this case, you may need to supplement your plant with fertilizer rich in the minerals it’s lacking. Be careful not to create an excessively high pH in your soil when treating the problem.

III. Types of Dwarf Flowering Almond

The most common cultivar of this tree is ‘Rosea Plena’, also sold as ‘Sinensis,’ with light pink flowers. Other cultivars that offer slight variations in flower color and structure include:

• P. glanulosa ‘Alba Plena’: This shrub is identical to ‘Rosea Plena’, but with white double flowers.
• P. glandulosa ‘Alba’: This cultivar has white flowers with a simple single-petal structure.
• P. ‘glanulosa ‘Lawrence’: This variety has single-petal pinkish-white flowers.