A close look at small trees

A close look at small trees

For years I had a favourite old crabapple tree at the entry to my house. In spring, soft-pink blossoms covered the tree, and in summer the limbs were heavy with tiny red fruits. Last summer, however, I reluctantly decided the crabapple had to go. It dropped so many fruits that I could hardly mow under the tree or walk on the sidewalk. So down came the tree, and off to a nursery I went to find a cleaner replacement-a small ornamental tree that would provide interest and screening at our entry without all the mess. It turns out that there were plenty of selections to choose from, depending on how and where I might use them. A flowering magnolia now stands about 10 feet from where the old crabapple tree stood, and its delicate springtime flowers and clean habit get rave reviews from both the neighbours and me.

Effective Uses for Small Trees

Many small trees that reach only 25 to 30 feet tall have interesting flowering, foliage, bark, berries, or form. They are especially effective in areas where other trees or plants wouldn’t work: in a limited space such as a courtyard, in a spot where you need screening, in a nook where a flowering tree would be welcome, or anywhere you want a unique focal point.

Small-space situations

If you live on a small city lot where a towering shade tree would overwhelm house and lawn, consider a small ornamental tree. For example, three flower maple (Acer triflorum, Zones 5 to 7) grows to 30 feet tall and 25 feet wide, has unusual peeling bark, and orange-to-red foliage in autumn.

Courtyards are perfect spots for small trees. They soften harsh corners and shade hot brick or concrete surfaces. Magnolia x loebneri ‘Leonard Messel’ has light pink flowers in spring, grows to 25 feet tall and 20 feet wide, and is hardy in Zones 5 to 9. When choosing a tree for an enclosed area like a courtyard, avoid one with messy fruit or seeds-it can be a chore to clean up after them (as I learned with my crabapple).

Small trees are a prime choice for areas under or near utility lines. Their size reduces the need for heavy pruning to prevent power-line damage. Apple serviceberry (Amelanchier x grandiflora, Zones 5 to 8) is a GreatPlants selection from the Nebraska Statewide Arboretum for this type of site. The cultivar ‘Forest Prince’ has outstanding white flowers, edible red berries, and red-orange fall colour. It grows 20 feet tall and 15 feet wide.

Screening

If your neighbours have a terrible-looking shed you would love to hide from view, but building a fence would deliver the wrong message, think about a small tree. Crabapple (Malus spp.) ‘Donald Wyman’ has a dense, spreading form, white spring flowers, and red fruit that stays on the tree all winter. It grows to 20 feet tall and 25 feet wide, and is hardy in Zones 5 to 8. Many newer crabapples hold their fruit into the winter and are not as messy as the older varieties. Each region has local cultivars of crabapple trees and unique soil conditions, so it’s best to consult local nurseries for the best selections for your area. Another tree good for screening is katsura (Cercidiphyllum japonicum f. pendulum, Zones 5 to 8). The cultivar ‘Amazing Grace’ has layered, weeping branches and grows to 25 feet tall and 30 feet wide.

Seasonal colour

Some lucky gardeners have flowers blooming all year, but most live in cooler climates where flowers are seasonal. Enduring a long winter is easier when you can look forward to spring-flowering shrubs and trees. Eastern redbud (Cercis canadensis, Zones 5 to 9) is listed by the Chicago Botanic Garden as one of the best flowering trees for Illinois. It has deep-red, pink, or white flowers in early spring (depending on the cultivar) and grows to 30 feet tall and wide with a spreading form. Magnolia (Magnolia grandiflora ‘Little Gem’, Zones 7 to 10) is evergreen in the South and is generally considered one of the best for humid, southern climates.

If you live in a dry, warm climate, consider two small trees that Wade Roitsch, propagator at Yucca Do Nursery in Hempstead, Texas, recommends. One is a redbud from Mexico (Cercis canadensis-Mexico form, Zones 7 to 10). Its leaves are smaller than the Eastern redbud, and the flowers are purple. It grows to 15 feet tall and 20 feet wide. The other is Eve’s necklace (Sophora affinis, Zones 8 to 9), a delicate-looking but tough tree that grows to 20 feet tall with an umbrella-like shape. It has blooms of pale-pink pea-like flowers and seed pods that resemble black-eyed peas.

Many of the maples, including amur maple (Acer ginnala, Zones 3 to 7) have outstanding autumn color. The amur maple grows to 30 feet tall and 25 feet wide. Japanese maple (Acer palmatum ‘Bloodgood’, Zones 6 to 8) has interesting features all season with purple-red leaves in summer and bright-red foliage and fruit in autumn. It grows to 15 feet tall and wide.

Outstanding Ornamental Trees

While spring has the largest selection of small trees, in the autumn your local nursery may have some excellent bargains. Otherwise, explore local botanical gardens and arboreta, and collect catalogs and earmark some fascinating smaller trees to grace your landscape next summer:

Bottlebrush Callistemon viminalis, Zones 10 to 11): Large shrub or small tree with bright red flowers in spring and summer. Grows 30 feet tall and 12 feet wide.

Cornelian cherry (Cornus mas ‘Golden Glory’, Zones 5 to 8): Yellow flowers in spring, edible red fruit, often multi-stemmed. Grows 25 feet tall and 20 feet wide.

Crabapple (Malus ‘Adirondack’, Zones 5 to 8): White flowers, red fruit. Grows 18 feet tall and 10 feet wide.

Crabapple (Malus ‘Pink Spires’, Zones 3 to 8): Grows 20 feet tall and 10 feet wide, fruit doesn’t persist in winter.

English hawthorn (Crataegus laevigata ‘Crimson Cloud’, Zones 5 to 8): Red flowers and fruit. Grows 20 feet tall and wide.

Fringe tree (Chionanthus virginicus, Zones 5 to 9): Large shrub or small tree with fragrant flowers, dark blue fruit. Grows 10 feet tall and wide.

Golden-rain tree (Koelreuteria paniculata, Zones 6 to 9): Yellow flowers, pink-red fruit capsules. Grows 30 feet tall and wide.

Hydrangea (Hydrangea paniculata ‘Tardiva’, Zones 4 to 8): Large shrub or small tree with white flowers in midautumn. Grows 8 feet tall and 8 feet wide.

Japanese maple (Acer palmatum ‘Bloodgood’, Zones 6 to 8): Grows 15 feet tall and wide, excellent foliage and bark.

Japanese tree lilac (Syringa reticulata ‘Ivory Silk’, Zones 4 to 7): Creamy white flowers. Grows 20 feet tall and 15 feet wide.

Kousa dogwood (Cornus kousa, Zones 5 to 8): Green flowers with white bracts. Grows 22 feet tall and 15 feet wide.

Magnolia (Magnolia ‘Butterflies’, Zones 5 to 9): Yellow flowers, likes moist site. Grows 15 feet tall and 11 feet wide

Nannyberry (Viburnum lentago, Zones 2 to 8): Large shrub or small tree with arching branches, white flowers, pink fruit that ripens to deep blue-black, grows 20 feet tall and 10 feet wide.

River birch (Betula nigra ‘Litte King’, Zones 4 to 9): Compact habit, interesting bark, multi-stemmed. Grows 10 feet tall, 12 feet wide.

Texas mountain laurel (Sophora secundiflora, Zones 7 to 10): Large shrub or small tree with fragrant violet flowers. Grows 35 feet tall and 20 feet wide.

Showy mountain ash (Sorbus decora, Zones 3 to 8): White flowers, orange-red fruit. Grows to 25 feet tall and 15 feet wide.

White Geiger (Cordia boissier, Zones 10 to 11): White flowers. Grows 10 feet tall and 8 feet wide.

Wild plum: how to find it roadside

Wild plum

Typically, when you’re looking for stunning garden specimens, you don’t go trolling the roadside. But that’s where I first became enchanted with wild plum: on a steep, dry embankment near an interstate. Every day I walked the overpass near a thicket of small, thorny, completely unremarkable trees. Then spring came, and I could smell the pungent white blossoms a block away. A few months later, the trees hung heavy with tiny, delicious, purplish fruits. I’d stumbled upon the perfect illustration of a wild plum’s life: it thrives on neglect and often congregates in wastelands; it suckers to form extensive colonies; and it produces loads of fragrant flowers in spring and edible fruit in summer. This little tree shows—as gardeners know better than most—that beauty is where you find it.

Common name: Wild plum, American plum, American red plum, hog plum

Botanical name: Prunus americana

Plant type: Deciduous small tree or large shrub

Zones: 3 to 8

Height: 15 to 25 feet

Family: Rosaceae

Growing conditions

Sun: Full sun to part shade

Soil: Average, well-drained

Moisture: Medium to dry. Found in the wild in rocky, sandy soils.

Care

Mulch: Three to six inches of organic mulch will help the soil retain moisture. Don’t mulch up against the tree trunk, as this encourages rot.

Pruning: Wild plum will sucker vigorously. If you want to keep it contained, prune suckers to the ground.

Fertiliser: None needed

Propagation

• By seed and cuttings.

Pests and diseases

• Borers, aphids, scale insects, and caterpillars can be problems.

• Leaf spot, plum curculio, brown rot, black knot, and canker can affect the tree.

Garden notes

• Be very particular about where you plant a wild plum. The ideal site is one where the plum’s suckering habit is a boon and not a curse: a place where you need a windbreak, or erosion control, or where you want to establish a patch of wildlife-friendly woodland.

• Wild plum flowers in the early spring. Some call the fragrance unpleasant; others say it’s spicy and sweet.

• The edible fruit, about 1 inch long, ripens in June or July. It’s said to be especially good in jams and jellies.

• If you don’t eat the fruit, the birds will.

• For the best fruit crop, plant two or more wild plums. Wild plums are also excellent pollinators for hybrid plums.

• Fall colour is yellow to red.

All in the family

• Canadian plum (Prunus nigra) is very similar to P. americana, and its range is about the same, though it is found further north. The cultivar ‘Princess Kay’ (P. nigra ‘Princess Kay’) is a popular ornamental with fragrant double flowers and sparse fruit.

• Other native Prunus trees include pin cherry (P. pensylvanica) and chokecherry (P. virginiana). Both produce fruit that can be made into jams and jellies or left for the birds.

Garden News: million year old Magnolia fossil found

Sweet bay magnolia

Drought is all over the news, but many gardeners have the opposite problem: a soggy low spot (or entire yard) that doesn’t drain well. Sweet bay magnolia (Magnolia virginiana) is perfect for these boggy areas, and gorgeous to boot. This heat-loving native thrives in the woodlands of the eastern and southeastern United States. It’s popular in gardens because of its lemon-scented, bright white flowers, which appear in the spring and summer, and its shiny green leaves with silvery undersides. Aromatic leaves and twigs add to the charm. Birds like the bright red berries.

Common name: Sweet bay magnolia, silver bay, swamp magnolia

Botanical name: Magnolia virginiana

Plant type: Deciduous or evergreen large shrub or small tree

Zones: 6 to 9 (warmer parts of Zone 5 with protection)

Height: 10 to 60 feet tall, depending on site

Family: Magnoliaceae

Growing conditions

• Sun: Full sun to part shade

• Soil: Rich, humusy, acidic

• Moisture: Average to moist

Care

• Mulch: Mulch to help keep soil moist.

• Pruning: Minimal pruning needed. Remove crossing or damaged branches.

• Fertiliser: None needed.

Propagation

• By seed or cuttings.

Pests and diseases

• Scale insects, weevils, and plant hoppers may attack Magnolia virginiana.

• May be vulnerable to canker, leaf spots, and powdery mildew.

Garden notes

• Your climate will determine the mature size and form of sweet bay magnolia. If you’re in the south, it can grow 40 feet tall or more. If you’re growing it in Zones 5 or 6, sweet bay may be a large shrub with multiple trunks, perfect for a specimen or screen, a foundation planting, or even for the back of a wide border.

• Take advantage of sweet bay’s tolerance for wet feet: Place it beside a pond or stream, or at the edge of a marsh.

M. virginiana grows between 1 and 2 feet per year.

All in the family

• Many relatives of M. virginiana are favorites in the garden. Northern gardeners rely on star magnolia (M. stellata, Zones 4 to 9) for early spring blossoms. Southerners are familiar with the cultivars of bull bay (M. grandiflora, Zones 7 to 9).

• Other popular garden magnolias include saucer magnolia (M. x soulangeana) and M. x loebneri (both hardy in Zones 5 to 9)—both of these have produced beautiful cultivars.

• There are about 125 species in the Magnolia genus, and they’re found primarily in Asia and the Americas.

• The magnolia is one of the first flowers to have evolved. Scientists have found magnolia fossils millions of years old.