Selecting Landscape Plants: Flowering Trees

Introduction

In the home landscape, flowering trees are secondary in importance to shade trees. The basic elements of framing, background, and shading are provided by shade trees, while flowering trees provide showy and unusual features with their floral beauty and seasonal interest. In addition, many flowering trees have colorful or interesting fruits which may be edible or attractive to birds or other wildlife.

Flowering trees must fit into the landscape. Only after deciding where they can be used most effectively should you try to select the variety to be used. If a certain type of flowering tree is desired, make the necessary changes to fit it into the landscape rather than simply placing it in the first open space.

Use relatively few flowering trees in the landscape. A small, residential property usually needs only two or three trees. Rows, large masses, and formal designs can be used more readily on estates or commercial properties.

Selection Factors

To select wisely among the many species and varieties of flowering trees available, consider:

• Mature size, form, and overall appearance of the tree.
• Light requirements, soil, and drainage needs.
• Intensity, duration, and color of the flowers and fruit; season of bloom.
• Cultural requirements, including pruning, fertilizing, and protection from insects and diseases. 

Give consideration to those trees with other striking features. Some trees which do not have spectacular flowers compensate by providing brightly colored or persistent fruits, pods, fall leaf color, bark, or uniquely colored summer foliage.

Whether a tree is considered a flowering tree is often a matter of opinion. All trees produce flowers, but whether we value them for the blossoms depends on how colorful, spectacular, or unusual they are. Few large trees are noted for their flowers. While their flowers may be noticeable, large trees usually are valued more for other reasons. Therefore, some of these are not listed in this publication but are described in VCE Publication 426-610, Selecting Landscape Plants- Shade Trees.

Fruiting characteristics and site selection should be considered together. Soft-fruited trees and those which attract birds create periods of inconvenience when they drop fruit and create litter problems on paved surfaces such as patios, walks, driveways, or game-courts.

Environmental Responses

Whether a flowering or fruiting tree lives up to its potential for health and beauty is largely dependent upon its environment: soil, water, light, and surrounding buildings and vegetation. Purchase flowering trees on the basis of their expected behavior under the prevailing growing conditions unless these conditions can be changed significantly.

Few trees tolerate wet or very heavy soils. Very sandy or gravelly soils cause problems for trees as well; they tend to remain too dry. Nearly all trees, however, respond favorably to deep and fertile topsoil with good internal drainage. When the soil is inhospitable, try to identify species that will tolerate that problem or add good soil in raised beds to help ensure that trees will thrive and flower well.

Flowering and fruiting are greatly influenced by duration and intensity of sunlight. Most flowering trees are adapted to full sunlight and perform better away from buildings or trees which cast dense shade during most of the day. Those preferring shade flower best where there is partial shade all day, or at least in the afternoon.

The form of most trees is variable, depending on the location. Planted in groups or in small openings, they will assume a form more upright than average. Trees planted in open areas will develop a broader crown and will not reach the same height as specimens that are crowded.

Availability and Adaptability

Our range of choices among flowering trees is largely determined by their general adaptability to the area. The climatic range over which a tree will thrive and flower well is usually reflected in the species or varieties offered in local retail nurseries and garden centers.

In the following list of recommended flowering trees, it is as impractical to list all the superior species and varieties as it is impossible for every garden center to stock all of them. Every retailer will have some desirable varieties not listed here. On theother hand, not all garden centers will have all those listed. When your retail outlet does not have the plant you want, they can usually obtain it for you if you are patient, or he may suggest a substitute.

Several trees which qualify as flowering trees are not available in the nursery trade or may have limited uses in the landscape. Many of those considered useful but perhaps worth seeking for special reasons are listed in VCE Publication 426-604, Selecting Landscape Plants, Unusual Trees.

A few of the outstanding native trees of Virginia are included in the list. These are not all readily available in the nursery trade at present. One reason for their appearance here is to encourage their preservation and incorporation into the landscape where they occur naturally. Another reason is to encourage use of some of our highly desirable, hardy, and well-adapted flowering trees in Virginia landscapes.

Flowering Tree Descriptions

In the following descriptions, the term hardy refers only to the extent to which trees survive the lowest winter temperatures. Most of the trees listed are hardy statewide.

Heights of trees are given for mature specimens grown on superior soils and within a favorable climatic range.

Generally, it takes many years to achieve such growth. In less favorable soils and climates, the trees will grow more slowly and these heights may never be reached.

Where fruits are indicated, an arbitrary size range is assigned. Fruits ranging up to 3/8 inch in diameter are termed small. Between 3/8 inch and 3/4 inch they are called medium. Large fruits are larger than 3/4 inch.

Cornelian Cherry
Cornus mas

Rounded with dense, ascending branches, this shrub-like but vigorous tree eventually reaches 20 feet in height. Clusters of small, yellow flowers appear before the lustrous foliage, which turns red in fall. The fruit is medium to large, maroon-red, cherry-like, edible, and attractive to birds. Use as a specimen or in groups or borders. It prefers excellent soil, is hardy, and relatively pest-free.

Crab apple
Malus spp.

Crab apples are among the most popular flowering trees. Not only are they splendid in bloom but also versatile in tree formand growth habit. Some are also prized for their attractive or persistent fruits which attract birds. There are more than 200 named varieties of crab apple.

The choice to use crab apples in the landscape should be accompanied by a willingness to attend to their maintenance if their full value as ornamentals is to be realized. Pruning is necessary to maintain the proper growth habit. Apple scab, cedar apple rust, and fireblight are all serious diseases of crab apples which require some control; try to use disease-resistant cultivars. Powdery mildew can be a fall disease problem, and cankers may develop where equipment makes wounds in the trunk. Chewing and scale insects, borers, and even mice (in weedy or brushy areas) will sometimes attack the tree. Diseases can be prevented and insects controlled by following the spray schedule described for apple trees in VCE Publication 456-018, Pest Management Guide For Home Grounds and Animals.

There are numerous varieties that have been selected as among the best, based on their disease resistance and ornamental characteristics. Contact your local VCE extension agent for recommendations of varieties. Crabapples may not perform as well in the Tidewater areas where summers are hot and dry.

Eastern Redbud
Cercis canadensis

This native tree grows from an irregular but attractive spreading crown. Small, purplish-pink flowers appear in clusters before the leaves show. The foliage is yellow in the fall, but drops quickly. Clusters of dark-brown pods persist through fall and winter. The tree is used as a specimen, planted in masses, or naturalized at the edge of woods. It is hardy and tolerant of a wide range of soils and light intensities. Also available are white and true-pink varieties; the latter color is easier to blend into the landscape than the purplish-pink color of the common species. Even more showy is the related Chinese species, C. chinensis, which is a smaller more shrubby form. C. canadensis ‘Forest Pansy’ has reddish-purple leaves. (20 to 30 ft. height; 25 to 35 ft. spread).

European Mountain-Ash
Sorbus aucuparia

Upright when young and spreading at maturity, this vigorous, rapidly growing tree reaches 45 feet on the best sites. Flat clusters of fragrant, white flowers appear in late spring and clusters of small, orange-red berries that are attractive to birds appear in the fall. The loose, compound foliage turns reddish in fall. The tree is best used as a specimen. It is subject to sunscald, borers, and fireblight. Varieties available include cutleaf, weeping, upright, and yellow-fruited types. Mountain-ash, being best adapted to cooler climates, should perform well in northern and western Virginia. It is not recommended for wetor disturbed soils or for the Tidewater area.

Flowering Cherry
Prunus spp.

Among the many flowering cherries, only a few are both spectacular and reliable enough for use throughout Virginia. They serve as specimens, accents, borders, or in groups. Most are slow growing. They respond well to good soil or soil improvement and tend to decline in vigor on poor or heavy soils. Cherries will not tolerate wet soils. The fruits of most flowering cherries are hardly considered ornamental but are very attractive to birds. Attention must be given to pruning, fertilization, and borer control.

Double-Flowered Mazzard Cherry —This dense, pyramidal tree grows to 40 feet and is hardy statewide. The double, white flowers last for 7-10 days, and the medium-sized, edible fruit is attractive to birds.

Higan Cherry —A dense, rounded tree, this variety reaches 30 feet in height. The light-pink flowers may be single or double and produce small, black, inconspicuous fruits. A pendulous, weeping variety is the most popular.

‘Kwanzan’ Cherry —The hardiest and most reliable form of Oriental Cherry, this variety has double, pink flowers and an upright growth habit that stays under 30 feet.

Sargent Cherry —The dense, upright growth habit of this tree reaches 50 feet. It is hardy statewide, with bronze-colored foliage in spring that turns green in summer and red in fall. The deep-pink, single flowers produce small, black, inconspicuous fruit. A narrow, columnar variety, ‘Columnaris,’ is also available.

Yoshino Cherry, Prunus x yedoensis — This tree has pink or white flowers and upright to spreading branches reaching from 25 to 50 ft. high. This flowering cherry is hardy throughout Virginia. Several cultivars, including a weeping form, are available.

Flowering Dogwood
Cornus florida

Unquestionably the most popular of our native flowering trees, the dogwood is the official state tree of Virginia. Its growth habit is rounded to upright with open, horizontal branching. The growth rate is slow to moderate, eventually reaching 30 feet. The tree is covered with white bracts surrounding small yellow flowers before the leaves appear. Red, glossy, medium-sized fruits persist in the fall when the foliage turns a lustrous scarlet. It is used as a specimen, in masses, or naturalized under large trees. Dogwoods prefer deep soil that is moist but well-drained. Avoid hot, dry exposures and improve tight or shallow soils. More dogwoods die from being wrongly planted in full sun in dry, compacted soil than from any other cause, especially in the Tidewater area. Always apply a mulch, and water during periods of drought. Old or injured specimens are subject to borer damage. Some of the more interesting varieties:

‘Cherokee Princess’ — white flowers, crimson-purple fall foliage

‘Appalachian Spring’ — white flowers, good fall color

‘Appalachian Snow’ — white flowers, dark red fall foliage

‘Appalachian Mist’ — white flowers, red fall foliage ‘Cherokee Brave’ — red flowers, good fall leaf color

C. ‘Rutgan’ Stellar Pink® — vigorous, erect growth habit, low branching; rounded, overlapping, textured, pink bracts not as showy as dark red bracts of C. florida

New cultivars include some with even deeper reddish-pink flowers, variegated leaves, or weeping growth habits.

Flowering Plums
Prunus spp.

The most popular plums are those which have reddish-purple foliage. Trees are rounded to upright, densely branching, with double or single flowers. The varieties with brightly colored foliage include ‘Newport’and ‘Thundercloud.’‘Atropurpurea’and ‘Nigra’ (Black Myrobalan Plum) have darker foliage colors. Fruit, when present, is edible but not ornamental. The plums require regular maintenance—pruning, fertilization, and occasional spraying—to maintain vigor. Sunscald is often destructive to unshaded or unprotected trunks, and many insectscan cause problems. (various sizes; depends on variety).

Fringetree
Chionanthus virginicus

A small, native tree with a spreading habit that is hardy throughout the state. Panicles of showy, fine-textured flowers appear in late spring. Fringetree tolerates most soils and prefers full sun. Fall color is usually yellow, but varies. This is a highly recommended small tree or shrub, although Chinese fringetree (C. retusus) is a more showy and adaptable species. (12 to 20 ft. height; equal spread).

Goldenraintree
Koelreuteria paniculata

The large, conspicuous, yellow flower clusters of the goldenraintree are produced in late June when few other trees are in bloom. The flowers are followed by showy, bladder-like fruit that hangs like clusters of small Chinese lanterns until late in the fall. It will grow in a wide variety of soils and has no serious insect or disease pests. However, it is a relatively short-lived tree. (30 to 40 ft. height; spread may equal height).

Hawthorn
Crataegus spp.

There are many species and varieties of hawthorn. They are valued for their profuse flowers, fruits, and picturesque growth habit. They are dense and thorny plants with white flowers and red fruits, though exceptions to these characteristics exist. Many are native to North America. They grow well in all but the wettest and poorest soils and are used as specimens, naturalized at the edge of woods, or in large formal plantings. The fruit is highly attractive to birds. Hawthorn is subject to borers, cedar-hawthorn rust, fireblight, and leaf-eating insects. It is somewhat difficult to transplant. Annual maintenance is beneficial. A popular hawthorn without thorns is C. crusgalli var. inermis. (20 to 30 ft. height; similar spread).

Japanese Dogwood
Cornus kousa

This tree has a rounded shape with horizontal branching, reaching about 20 feet at maturity. The large, pointed, white to pinkish bracts are produced three weeks after the native dogwood blooms. The fruit is medium, reddish-pink, raspberry-like, and attractive to birds. The foliage turns scarlet in fall. The culture and uses are the same as flowering dogwood, except that this variety seems to be better able to tolerate full sun.

Saucer Magnolia
Magnolia x soulangiana

The natural habit of this tree tends to be shrubby with multiple stems and a rounded to spreading shape, but it may be trained to a single trunk. It grows rather slowly to 25 feet but begins flowering at an early age. The cup-shaped flowers are white, tinged with pink or purple, and appear before the leaves. There are many hybrids with other colors, including yellow and deep purple. Best used as a specimen or lawn tree, in small groups, or seen against a background of evergreens. The tree needs some care in northern and western Virginia, where late spring frost may injure flowers. Several later blooming cultivars are available that can help avoid this problem. To ensure survival, transplant in spring.

Serviceberry
Amelanchier arborea

Upright in youth and oval to spreading with age, this native plant has a slow to moderate growth rate depending upon the site. Its mature height may exceed 40 feet in the best locations. Masses of small, white flowers in nodding clusters appear in early spring, followed by maroon-purple, edible berries which are quickly eaten by birds. The fall foliage is yellow, golden, or red. Used as a specimen or lawn tree, in border masses, or in naturalistic groups, it prefers well-drained sites. It is occasionally damaged by an assortment of leaf eating insects. Many new cultivars exist.

Sourwood
Oxydendrum arboreum

Excellent native specimen plant usually growing slowly into an oval or pyramidal medium-sized tree, although it can be quite tall in some instances. White, pendulous flowers cover the tree in summer. Fall color is a spectacular red, often with purple and yellow as well. This tree prefers acid, moist soils that are well-drained; may have difficulty in the Tidewater area. (25 to 30 ft. height; 20 ft. spread).

Star Magnolia
Magnolia stellata

A dense, mounded, large shrub or small tree reaching 20 feet, star magnolia has large, white, star-like flowers in early April before the dark-green leaves appear. In fall, the leaves change to yellow, and bronze when in full sun. Best used as a specimen or in small groups, this variety also needs care in northern and western Virginia. Avoid southern exposures to prevent damage to early flowers by late spring frosts. For the best results, transplant in spring. This variety is generally pest free.

Sweet Bay
Magnolia virginiana

A 60-foot evergreen tree in the south, the sweet bay is shrub-like and deciduous near its northern limits. It is most commonly used in southeastern Virginia and tolerates wet soils, but thrives on well-drained soils. Attractive foliage, gray bark, and fragrant, white flowers in early summer make this an excellent specimen or lawn tree. For best results, transplant in the spring.

This publication adapted for Virginia from Selecting Landscape Plants- Flowering Trees, with permission from Lower and Long, Department of Horticulture, University of Missouri.