Pearlbush Shrubs: Drought-Tolerant Choice for Moon Gardens

White-Flowered Gem

Image: pearlbush just starting to bloom.
When pearlbush's flower buds are about to open, they look like pearls. David Beaulieu

Plant Taxonomy:

The taxonomy of pearlbush is Exochorda racemosa. Examples of some of the types available at garden centers are:

  • Snow Day™ Surprise (sometimes referred to on plant labels as the cultivar, 'Niagara')
  • Snow Day™ Blizzard
  • The popular hybrid, Exochorda x macrantha 'The Bride'

Plant Type:

Exochorda racemosa is a deciduous flowering shrub. It is one of those old-fashioned favorites associated with cottage gardens that, for whatever reason, have fallen out of favor in recent times.

Characteristics:

Common pearlbush matures to a height of about 10 feet, with a similar or slightly greater width. But the cultivars in the Snow Day series stay more compact, reaching 3-4 feet tall with a similar spread, meaning they are much better suited to small spaces. Plants bloom in May in my zone 5 garden. The white flowers appear in terminal racemes. The bluish-green leaves have an elliptical, oblong, or obovate shape.

Planting Zones for Pearlbush Shrubs:

These plants from China are suited to planting zones 4-8 in North America. Mulch for winter protection if you're a Northerner and live in an area where the bushes are only borderline cold-hardy.

Sun and Soil Requirements:

Grow this bush in full sun to partial shade and in a well-drained soil. Amend the soil with compost. Pearlbush shrubs like a soil pH that is on the acidic side. They are relatively low-maintenance plants once established.

Uses for Pearlbush Shrubs:

Possible uses for Exochorda racemosa are in foundation plantingsmixed shrub borders, and in loose hedges. I don't recommend it as a specimen plant, simply because it flowers for such a brief period and isn't much to behold at other times. Of course, that's no reason not to grow it.

Just be sure to surround it with complementary plants that will be in bloom when pearlbush isn't (or that supply visual interest through their attractive foliage).

Care (Pruning Information):

Pearlbush is one of the shrubs that bloom on old wood. Consequently, the time to prune (if  needed) is immediately after it finishes flowering. When might you need to prune it? An old bush might profit from a pruning to reinvigorate it (rejuvenation pruning). Or you might simply want to keep it as compact as possible if you are growing it in a small space.

Outstanding Features:

The common name derives from the appearance of the flowers before they open. Dangling there on the branches in their snowy brilliance, they look like so many pearls enticing you with their riches. These blooms are, however, the only aesthetic attribute of the shrubs that recommends them to the would-be grower.

I do, however, also appreciate the fact that, once established in a good loamy soil, pearlbushes can be considered reasonably drought-tolerant shrubs. I grew my own for many years in a neglected area of my landscape, where plants were often left to fend for themselves. My garden hose didn't reach this spot, nor did I stay on top of my weeding in this nook of my property, let alone bothering to fertilize.

While my pearlbush grew slowly under these challenging conditions, to its credit it did survive and blossom.

Other White-Flowering Shrubs:

Pearlbushes are not especially common. If your local nursery doesn't carry any (and if you're not particularly interested in buying online), rest assured that there are a number of more popular substitutes if all you want is a bush that bears white flowers in spring. Possible alternatives include:

Some gardeners grow plants with white flowers for use in so-called "moon gardens."