Great trees for landscapes

When someone asks “Can you recommend a tree for my landscape?” my first impulse is to jump up and down and say: “Look around you in the gardens and woods. There are so many choices, so many options — just pick one!”

But that’s just it. There are so many choices and so many options, it’s hard to know where to start. And if you’re new to the area, new to gardening, or feel overwhelmed by the many tree lists in books and on the Internet, it can be particularly difficult to whittle down the seemingly unlimited options to a usable list. Yet each list and each option underscores the importance of choosing the right tree for the location. And doing your homework — determining the soil type and moisture levels, sun/shade conditions, available room for the tree to mature unimpeded in the landscape, and (of course) how it fits into the overall design of the landscape — is critical to finding that one perfect tree.

To help make it easier (or at least to help narrow the focus), The North Carolina Arboretum has developed “Great Trees for Landscapes: A Selection of Recommended Trees for Landscape Planting.” This resource lists trees that can tolerate various soil types and conditions, possess a desirable seasonal color, fruiting or flowering characteristic, and perform well after an initial establishment period of one to three years (assuming the tree isn’t planted and forgotten but given water and other proper care). Most of the recommended trees are native, and all of them can be found in the Arboretum gardens.

The list is organized into three height categories — small, medium and large.

Small trees (10-25 feet tall)

* Paperbark maple — a slow-growing maple that’s native to China and is known for its beautiful cinnamon-colored, exfoliating bark, which provides excellent winter interest in the landscape.

* Fringe tree — often referred to as old-man’s-beard, this tree is known for its white, fleecy spring flowers. Although it resents transplanting once established, it is pest-free, requires little pruning, and tolerates city air.

* Flowering dogwood — cherished for its welcoming spring display of creamy white flowers (which appear before the leaves emerge), this tree has bright-red fruit that offers nourishment to overwintering birds in our area. Be sure to plant this beauty in a sunny spot and give it extra attention as it gets established to help keep the dogwood anthracnose disease at bay.

* Kousa dogwood — from Asia, it blooms later than the flowering dogwood, its pointed, four-petaled flowers appearing atop the newly emerged foliage. The tree’s ornamental fruit extends its season of interest. Kousa dogwood is particularly pest-free; it has been bred with the flowering dogwood to increase its disease resistance.

* Cornelian cherry — a central/southern European and western Asian tree, it is actually a dogwood (though the flowers are very different) and has little competition in the landscape, since it’s one of the first to bloom.

* Smoke tree — hailing from southern Europe and central China, it has not-very-showy flowers with small hairs along the stems that give this plant its name. As the flowers mature and fade, the hairs go through various color changes, the most spectacular being the smoky pink phase. There are several purple leaf forms available that, alone or in groups, can create an unrivaled point of focus in the landscape.

* Flowering crabapple ‘Adirondack’ — one of more than 800 cultivated varieties available, it has spectacular spring flowering and fall fruiting characteristics. Crabapples in general have many disease and pest problems, but ‘Adirondack’ has proved to be quite resistant. Many studies and recommendations are available for “best” varieties; be sure to look for those trees that are the most disease- and pest-resistant.

Medium trees (25-40 feet tall)

* American yellowwood — a hardy native tree growing as far north as Minnesota, it’s a good specimen shade tree with fragrant white flowers clustered on irregular stems. This tree can be slow to flower when young (though it’s well worth the wait), but once established, it’s very pest- and problem-free.

* Green hawthorn ‘Winter King’ — one of the best hawthorns, it provides color interest in the landscape throughout the year. The spring flowering display is incredible, and the heavy fruit set lasts well into the fall and early winter.

* American holly — this evergreen tree with deep-green, spiny leaves is best known for its wonderful red fruit, relished and disseminated by birds. Best planted in moist, well-drained soils, this holly can be used alone or in a grouping. As new leaves emerge in early spring, it is prone to what I call the “ugly yellow leaf phase.” Look for cultivated varieties such as ‘Satyr Hill’ and ‘Miss Helen’ to avoid this and other pest problems notorious to the species.

* Black tupelo — this adaptable species makes an excellent choice for a specimen tree or for use in native plantings. Summer leaf spot can be problematic but doesn’t interfere with its consistent, multihued yellow, orange, scarlet and purple fall color show. Best moved as a young container plant, it does not transplant well once established, due to taproot development. Pick your spot and leave it!

* Sourwood — a great specimen tree for all seasons, with its lacy white flowers and brilliant fall foliage. A home for honeybees intent on making sourwood honey, this tree establishes best if transplanted as a field-grown plant into sunny, well-drained locations in the landscape.

Large trees (at least 40 feet tall)

* Red maple ‘October Glory’ — one of many cultivated varieties selected for its consistent orange-to-red fall color, it is ozone-tolerant and adaptable to varied environments, from swamps to city streets.

* Sugar maple ‘Green Mountain’ — Like the red maple, it offers superior fall color with yellows, orange and red all on the same tree, but it’s less tolerant of difficult planting situations or air pollution. ‘Green Mountain’ is resistant to leaf scorch, which can a problem with sugar maples.

* River birch ‘Heritage’ — this easy-to-transplant variety will thrive in moist soils but is tolerant of other soil types as well. Essentially pest-free (except for leaf spot in a wet season), it has beautiful exfoliating bark, and the multistemmed form makes a wonderful specimen in the landscape. What more could you ask for? (For a smaller version, check out ‘Fox Valley’, which only gets about 10 feet tall.)

* American sweetgum ‘Rotundiloba’ — the American fruitless sweetgum, it’s an obvious choice for folks who love the rich yellow/red/purple fall color but hate the species’ messy fruit. Given adequate room for root growth, this tree is great for lawn and street planting.

* Scarlet oak and white oak — both are an asset in any landscape planting, especially in large, open spaces where their form can fully develop. Plant a ground cover underneath, since the root competition and shade will make an unsuitable environment for turf grass. Oaks are best planted and left alone for many future generations to enjoy. Acorns are essential components of many birds’ and mammals’ diets.

* Bald cypress — this deciduous conifer drops its fine-textured leaves after a spectacular fall display of orange to golden brown. An unusual landscape tree is comfortable in swamp conditions as well as dry city sites. If planted near water individually or in groves, “knees” will form adjacent to the buttressed trunk, adding further interest to an already attractive specimen.

Fact sheets, available in the lobby of the Arboretum’s Visitor Education Center and on the Web site (www.ncarboretum.org), give more detailed information about each tree and related species or cultivars, along with helpful planting-and-staking techniques. It’s safe to say that this represents only the tip of what’s available in terms of tree choices for the landscape. And if “Great Trees for Landscapes” inspires and motivates informed plant choices for the landscape, well, that’s great!

[Alison Arnold is director of horticulture at The North Carolina Arboretum.]