OREGON STATE UNIVERSITY EXTENSION SERVICE Trees and Shrubs for Fall and Winter Bloom 28 Species Attractive N. Bell, H. Stoven and A. Melathopoulos fter autumn leaves drop, gardeners often to Pollinators and People “put the garden to bed” for the year. The West of the Cascades Agarden could be forgotten until spring arrives again. However, bright spots in the garden can add visual interest and needed cheer at this time of year. Winter is an opportunity to highlight structural aspects of the garden as well as provide habitat and food for wildlife at an otherwise lean time. One way gardeners achieve winter interest is by adding plants with colorful evergreen foliage or attractive bark. But we are fortunate in the maritime Pacific Northwest to be able to grow a number of plants and shrubs that brighten the garden with blooms and sweet fragrance during dark winter months. Most trees and shrubs go dormant in fall and save their blooms for spring or summer. However, some begin blooming in fall or winter. Cooler winter weather will often extend bloom time, with some displays lasting a month or longer. The area west of the Cascade Mountains generally has mild enough winters to grow a wide range of winter- blooming shrubs. Most days stay above freezing, even in midwinter. Although cold spells can kill some floral buds and damage flowers that are open, new blooms often emerge soon after the cold weather ends, returning the plant to glory. The plants in this publication are hardy enough Neil Bell, community horticulturist and professor of practice, Marion and Polk counties; Heather Stoven, Extension horticulturist, Yamhill County, and assistant professor of practice; Andony Melathopoulos, pollinator Photo: J. Kehoe, CC BY 2.0 health Extension specialist and assistant professor; all of A yellow-faced bumblebee visits manzanita flowers. Oregon State University. EM 9277 March 2020 to grow in the open garden in most locations west of BLOOM TIME: SEPTEMBER—OCTOBER the Cascades, but consider the various microclimates in your garden before planting. Microclimates are areas which can differ in climate in comparison to the surrounding area. These differences can be caused by vegetation, elevation, bodies of water, aspect (the direction an area faces) or slope. Microclimates can make a difference even for small properties. For example, plants placed next to homes or buildings are more likely to resist damage during a cold spell. The added heat from buildings can also change the timing of blooms. When deciding where to plant late-fall- and winter- blooming shrubs, consider their location in relation to windows or doorways. This way, you can see their flowers while gazing out or while coming and going. Many winter-blooming shrubs are fragrant, so place Baccharis pilularis ‘Twin Peaks’ these plants where you can enjoy the perfume. Flowering shrubs also boost pollinators, providing COYOTEBRUSH nectar and pollen when little is available. Anna’s Baccharis pilularis hummingbirds are year-round residents in western Oregon. They feed on nectar when they can find Coyotebrush is native to the it but also supplement their diet with insects. Oregon Coast and ranges Winter-blooming plants can provide them needed south into California. It is carbohydrates. usually seen as a medium to large (topping out around European honey bees are Flowering shrubs 8 feet), rounded shrub. active right through the winter also boost However, many cultivated Baccharis pilularis flowers and visit many flowering shrubs varieties are mounding, pollinators, when temperatures rise above spreading groundcovers. Evergreen 55 degrees F. Although most of providing nectar Coyotebrush is in the daisy Height and width: up to Oregon’s 500 species of native family (Asteraceae), but the 8 feet tall and wide. Some and pollen when bees go dormant in winter, some, inflorescence consists only of cultivars are much smaller. including bumblebee queens and inconspicuous disc flowers, little is available. not the showy ray flowers Fragrance: Subtle, pleasing several of our solitary mining fragrance. bees, are active as early as characteristic of many Aster family members. Coyotebrush Cultural requirements: Full February and March. The pollen and nectar in these is dioecious, meaning it has sun with some protection blooms are essential to these bees, fueling their search separate male and female from winter cold inland. No for new nests and provisioning their first brood. Late plants. Male plants are summer water. Plants can be fall blooms can be critical for late-foraging pollinator preferred in cultivation since shaped with light shearing in species building fat reserves to last the winter. female plants produce large spring. Note that while many winter-blooming plants numbers of wind-blown seeds. Hardiness: USDA zones 8-9. produce nectar and pollen, some are shaped in ways Male plants have yellowish Susceptible to cold injury in that restrict certain pollinator species. Typically, flowers with a subtle, pleasing cold winters. (See the USDA scent in September and bumblebees and hummingbirds have the longest Plant Hardiness Zone Map at October. Female plants have bit.ly/zml8bo/.) tongues and can reach down into longer flowers such white flowers. Coyotebrush as currants and heathers. is susceptible to injury in cold Attractiveness to winters and is best grown in pollinators: Very attractive a sheltered location. Buck to honey bees, a wide The following shrubs reliably bloom and add interest deer will rub their antlers on variety of late-season bees during fall and winter in the maritime Pacific Baccharis, which can cause and some butterflies and Northwest. They are listed roughly in order of bloom, damage. If injury does occur moths. although the length of bloom of individual plants or if shaping is required, Cultivars: ’Twin Peaks’, varies greatly. Bloom timing can also vary year to prune plants in spring. ‘Pigeon Point’, ‘Pistol year due to variations in winter temperatures. Warm Pancake’. winters can lead to earlier bloom times. 2 OCTOBER–NOVEMBER NOVEMBER–DECEMBER Mature strawberry tree Fatsia japonica ‘Variegata’ STRAWBERRY JAPANESE TREE FATSIA Arbutus unedo Fatsia japonica Strawberry tree is Japanese fatsia is native native throughout the to Japan and South Mediterranean basin and Korea, where it occurs as also occurs in Ireland. It gets a modest-sized upright its common name from the shrub in woodlands. The large size of the species and Strawberry tree flowers and fruit leaves are large, dark green Japanese fatsia flowers the spherical red fruit. The and conspicuously lobed, fruit are produced from the Evergreen which gives the plant a Evergreen previous season’s blooms Height and width: 15 feet tropical appearance in the Height and width: Up to and ripen at the same time tall by 20 feet wide. Listed landscape. The flowers 10 feet tall and wide. Slow as the new blooms occur, cultivars are far smaller. are white and produced in growing. in fall. The fruit are edible Fragrance: No fragrance. spherical clusters about Fragrance: No fragrance. and though not often the size of a golf ball, which consumed fresh, are used Cultural requirements: Full are borne in large panicles Cultural requirements: Part in preserves and distilled sun. No summer irrigation above the foliage. The flower shade to shade. Best with spirits in Europe. Strawberry once established. If placed display is unique, but they occasional summer water. tree forms a dense, where it has enough space, are sensitive to cold, and a Hardiness: USDA Zone 8. these plants require no rounded shrub or tree with hard freeze usually brings Attractiveness to pruning. leathery, dark green leaves. flowering to an end. Some pollinators: Attractive to Depending on the cultivar, Hardiness: USDA Zone 8. variegated cultivars are flower flies. the flowers are white to Foliar damage can occur at available. This unusual shrub Cultivars: ‘Variegata’, pink, urn-shaped and occur 10 degrees F or below. is suitable for protected, ‘Spiders Web’. in 2-inch-long clusters in Attractiveness to shady spots in the landscape abundance. pollinators: Honey where the flowers might be bees, bumblebees and better protected from cold. hummingbirds. Cultivars: ‘Elfin King’, ‘Compacta’, ‘Oktoberfest’. All photos by Neil Bell, © Oregon State University, unless otherwise noted 3 OCTOBER–NOVEMBER LATE FALL Holly tea tree in bloom Mahonia eurybracteata in bloom Photos: Jeff Stoven HOLLY MAHONIA OSMANTHUS EURYBRACTEATA Osmanthus heterophyllus This evergreen shrub is native to China and is Holly osmanthus is one distinctive due to its narrow of several fall-flowering and smooth-edged leaves, Osmanthus, but O. separating it from some heterophyllus is the hardiest, of the other spiny-leaved most commonly grown Mahonias. The foliage can species. It is a native of Holly tee tree flowers appear tropical with the Flowers of M. eurybracteata Japan, where it forms a fine texture of the leaves. Evergreen Evergreen dense, upright oval shrub. This plant prefers partial to The leaves are shiny dark Height and width: 10 feet full shade. In late fall this Height and width: 3–6 feet green. Juvenile leaves are tall and 6 feet wide. Cultivars shrub sends up bold spikes depending on cultivar. notably spiny while adult may be far smaller. of yellow flowers that attract Fragrance: Lightly fragrant. leaves — produced near bees. Silver-blue berries Fragrance: Flowers are very Cultural requirements: the top of the plant — lack follow later in winter. fragrant. Part sun to shade, average spines. Mature plants may Cultural requirements: moisture needs. consist primarily of smooth Full sun, summer irrigation. leaves. The flowers are Hardiness: USDA Zone 7. Responds well to pruning, small, white and borne in Attractiveness to and vigorous forms are often groups of four to five in pollinators: Very attractive made into hedges. leaf axils. Although this to honey bees and late- plant is not conspicuous in Hardiness: USDA Zone 7. season bumblebee queens bloom, the flowers are highly Attractiveness to preparing for winter.