A common sight between the Willamette Valley and the coast during the summer is the frothy sprays of creamy white flowers covering stands of Holodiscus discolor, interspersed along the highway; maybe an obvious explanation of how it got the common names “Oceanspray” and “Cream Bush.”
It appears in such lush quantity along roadsides because it is one of the plants that is successful establishing itself in disturbed areas; frequently one of the pioneer species to take hold in places that have been affected by forest fire or clear-cutting. Advantageous that it does so, as Holodiscus is an attractant to butterflies and other beneficial insects, and provides cover for birds. It is useful in the process of reclamation as well as a good wildlife plant for the home garden.
There are two native species of Holodiscus found in Oregon:
Oceanspray, Cream Bush
This multi-stemmed shrub is commonly found at low to mid-elevations in almost every county in Oregon. It is widely adaptable to many soil types, amount of moisture and degree of sun/shade.
The stems of Oceanspray are slender but dense and hard – coastal tribes used the wood for arrows and digging tools, sewing and knitting needles, and even as joining pins for construction in pre-nail times – growing straight to slightly arching at a height of 10-20’ tall and wide. Mature stems and branches have an attractive reddish peeling bark. Leaves are lobed to roughly toothed, looking similar to black hawthorn. They have good, yellow to reddish fall color.
The flowers are a frothy cascade of many tiny, fragrant, five-petal blossoms, starting out as white, fading to cream and finally to brown as they age. Some of the clusters of small fruits that follow often persist into fall and can even overwinter, not being the favorite food of wintering-over birds. Its lush foliage and flowers during the year make it a good shelter tree for birds, however, and the flowers may attract butterflies to your garden.
Other than occasional pruning to shape, there is little maintenance required. Oceanspray is also not prone to disease or pests, making it a congenial specimen for a sunny/woodland garden.
Dwarf Oceanspray, Desert Oceanspray, Rock Spirea
This is the Oceanspray of the drier high country east of the Cascades. Among other places, it can be found in the arid pumice and volcanic ash soils of south-central Oregon, so to make it happy here in the wetter west side of the state would require a little effort and thoughtful placement out of the force of winter rains.
It is a smaller version of H. discolors in many ways, with similar leaf shape and flower structure, and reaching a height of only 6-15’. The bark is smooth and gray, and the leaves turn orange-red in fall.
Less commonly available in nurseries, it can nevertheless be a beautiful addition to a garden if the soil and drainage requirements are met by placing it in rock garden or container.
Common Name: (H. discolor: Oceanspray, Cream Bush. H. dumosus: Dwarf Oceanspray, Rock Spirea)
Origin: (H. discolor: Western North America, including almost every county in Oregon in sites low-to-medium elevation. H. dumosus: Central Oregon eastward, in rocky, dry habitat).
Characteristics: Erect to arching branches on multi-stemmed shrub. Leaves are small and slightly lobed/toothed, similar to Hawthorn. Flowers in mid-summer with tiny flowers massed in drooping panicles that change from white to cream to brown as they age.
Culture: Grows in full sun to partial shade, moist to dry conditions, depending on species. Good selection for a butterfly garden.
Maintenance: Virtually maintenance-free.
Pests & Diseases: Very little in the way of pests and diseases; fungal leaf spot and fire blight have been reported, but are not prevalent.