Mother Nature's Backyard - A Water-wise Garden: February 2019

Western Chokecherry (Prunus virginiana var. demissa):
Mother Nature's Garden of Health

It’s difficult to conjure up a February-appropriate plant that we haven’t previously profiled. But one that’s getting to a reasonable size is the Western chokecherry, Prunus virginiana var. demissa, in Mother Nature’s Garden of Health. The scientific name is pronounced: PROO-nus ver-jin-ee-AN-uh dee-MISS-uh.

Prunus virginiana is native to North America. It once grew wild in much of Canada, the United States and northern Mexico. There are two recognized varieties: Prunus virginiana var. virginiana (the eastern chokecherry, native to the eastern US and Canada); and Prunus virginiana var. demissa (the western chokecherry, native from WA, OR and CA east to the Rockies and Mid-West).

In California, Western chokecherry grows in many wooded and shrubby habitats from San Diego County to the Oregon border, at elevations below about 8000-10,000 ft. (2500 m.). It’s not native to either the Southern California coast or the Central Valley, and grows mostly in areas with winter snow, or near seeps and stream bottoms. In Los Angeles County, it can still be seen in the Liebre and San Gabriel Mountains – and in gardens. It grows in most foothill and mountain plant communities, especially scrub lands, oak/pine woodlands and coniferous forests.

Western Chokecherry (Prunus virginiana var. demissa):
Four year old plant

Prunus virginiana is a large shrub or small tree. It varies greatly in size and form, sometimes appearing as a 3-4 ft. shrub. In other sites, it can achieve mature heights of 20-30 ft. (6-9 meters). Its mature spread can be 15-20 ft. The overall form is erect, with many slender branches. The bark is reddish on new growth, becoming gray. Some plants are shrub-like, with much branching from the base. Others are more tree-like, with a central leader. In some situations, Chokecherries form dense thickets. This characteristic makes them particularly suitable for hedgerows and screens. For more photos of Chokecherry plants see reference 1, below.

Western Chokecherry (Prunus virginiana var. demissa): leaves

Chokecherries are winter-deciduous, losing all their leaves in late fall in colder climates. In cold climates, leaves turn an attractive gold or orange in fall, making them a good source of fall color. In warmer sites (like Mother Nature’s Garden of Health), plants may retain their leaves well into winter in some years. The leaves are simple, ovate to elliptical, with finely-toothed margins. The new leaves are bright green in spring, maturing to medium or dark green above and slightly paler green beneath. The leaves contrast pleasantly with the bark, which is smooth and dark red on younger twigs and often gray on mature branches. The foliage is a larval food source for Small-eyed Sphinx Moth & Columbia Silk Moth.

Like many members of the genus Prunus, parts of the plant are toxic. New growth, wilted leaves, or plant parts injured by frost or drought are particularly harmful if ingested by humans or animals. Domestic cattle and sheep have been poisoned eating too much foliage. Despite this, Chokecherries are widely used as a forage plant in wild. Animals as varied as bears, moose, coyotes, bighorn sheep, pronghorn, elk, deer and smaller mammals all browse Chokecherry.

Western Chokecherry (Prunus virginiana var. demissa): Flowers
photo by Mary Winter, Cal Photos

Chokecherry flowers have many characteristics typical of the genus Prunus. The flowers themselves are small, white to cream-colored, with five simple petals (flower parts in fives). The flowers are arranged along drooping, 2-5 inch flowering stalks, and may be densely packed. Plants are very showy in bloom, and the species is often used as an ornamental shrub/tree in home landscapes. The flowers are sweetly scented – with a slight hint of almond – and attract a wide range of pollinators, including native bees and butterflies.

Western Chokecherry (Prunus virginiana var. demissa): ripe fruits

Chokecherry is probably best known for its fruits. The fruits are small (1/4 to ½ inch), shiny ‘cherries’ that begin green, then ripen to either red, dark-red or almost black (Four Corners States; Rockies). Even when ripe, the raw fruits are very bitter, hence the common name ‘Chokecherry’. None-the-less, birds and animals relish the fruits. If you grow Chokecherry for its fruit, you may need to protect the ripe fruits from hungry birds!

The seeds (pits) contain high concentrations of hydrogen cyanide, a potent poison. Fruits should not be eaten raw; however they can be cooked to render the fruit non-toxic, particularly when the seeds (pits) are removed after cooking. Chokecherry jelly and syrup are highly prized for their color and cherry flavor. They are one of the favorites at garden gourmet events in our gardens.

Western Chokecherry (Prunus virginiana var. demissa): jelly

Chokecherries can be grown in all but the heaviest clay soils. They don’t do well in soils with pH > about 7.8. They are shade tolerant and do well in part-shade and under trees. While they can be grown in full sun (with adequate water), they are probably most successful when given afternoon shade in Southern California. Chokecherries like a richer soil than many of our local natives. Organic mulch can be used to supply nutrients – or fertilize with a low-dose fertilizer in spring.

Chokecherries also need some summer water. They have some deep roots, but also many shallow roots. In the lowlands of Southern California, they likely will need water every 2-3 weeks from June through September. We water our Prunus virginiana every other week in Mother Nature’s Garden of Health. The soil dries out between waterings in our clay-loam soil. We’ve also located our plant on the north side of a tall wall, providing more shade than in most of our garden.

Western Chokecherry (Prunus virginiana var. demissa)

Like most Prunus (plums, cherries, peaches, nectarines, apricots, almonds) Prunus virginiana is susceptible to black knot fungus, fireblight, and several other diseases. In general – and with judicious watering – it is healthier then the domesticated Prunus. But keep an eye out for disease, and prune out diseased wood right away (using sterile pruners). Western chokecherry has a pleasant natural shape. Unless you’re training your Chokecherry to a tree or espalier it won’t need much pruning. But you will need to prune off the root suckers, which can be common in this species.

If you’re in the market for a large shrub/small tree Prunus virginiana has much to recommend it. It can be used in a mixed hedgerow or pruned up as a shade tree. In our garden, we are espaliering our Chokecherry along a wall (most Prunus are good candidates for espalier). The foliage is pleasant and the flowers are showy and fragrant. The fruits can be used to make delectable jelly, syrup, fruit leathers, cordials and wine – or left as habitat for fruit-eating birds.

Western Chokecherry (Prunus virginiana var. demissa):
Rancho Santa Ana Botanic Garden, Claremont, CA

Traditional medicine used tea made from the bark for stomach ailments, coughs, colds and diarrhea, and as a sedative. The ‘tea’, as well as a poultice made from the leaves, was used to treat cuts, sores, bruises. Dried, powdered bark was used similarly. The ripe fruit is a laxative. And leaves, bark and fruits can be used as natural dyes.

In short, Western Chokecherry is an attractive shrub/tree with many uses. It’s one of those native plants that provides lots of value for its cost – and the space it takes in a garden. If you need a large shrub or small tree, Prunus virginiana may be right for your garden.