By Laurie Sprague

Trees still do all the things we learned about in the third grade, and slowly but surely they’re getting the recognition they deserve. A discussion about the intractable problems of climate change? Trees are front and center as a solution to cleanse and cool the air around us. Want to sell something to a certain segment of the population? Promise to plant a tree with every purchase. Want to cut trees down? Prepare for battle as fans gather around them (and in them) to defend their value. Hollywood itself will soon make trees the unlikely focus of a movie. Production companies headed by Amy Adams and Jake Gyllenhaal recently bought the rights to Finding the Mother Tree, Suzanne Simard’s new book about how trees communicate with other living things; Adams is set to play Simard. (Filmmaker James Cameron’s Avatar and novelist Richard Powers’s The Overstory are said to draw heavily on Simard’s once-disparaged research.) As trees become central characters in the Earth’s drama, their biological and psychological benefits to other species—humans, especially—get more recognition. Trees have been lauded for everything from nurturing moss, insects, fungi, animals, and plants to reducing anxiety. And of course, people will always feel connected to certain trees—one they climbed on or played under as a child or one that filters the light coming in through the bedroom window just so.

On a simpler level, trees also make homes homier. “Trees provide functional and aesthetic value to any developed property,” says Brian Sawyer, a landscape architect and founding partner of the New York design firm Sawyer | Berson. “They screen the sun to provide shade where it’s desirable,” he says, and they can help define a space, channel or reduce wind speed, and reduce the effects of “heat islands” in overdeveloped or urban areas. A property with healthy, mature trees is worth an average of 10 percent more than one without them, says the U.S. Forest Service. Indeed, according to a recent story in The Wall Street Journal, “trophy” trees—huge, old, full-growth specimens, scouted by professional “tree relocators” and moved by helicopter, barge, or truck to their new homes, for huge sums—are the newest status symbol for wealthy American homeowners.

After all, even the most beautiful home can look naked and unfinished without trees framing and protecting it. Sawyer, whose firm approaches architecture and landscape design as complementary tasks, says trees are the building block of any landscape. “Shade trees and evergreen trees provide structure, scale, and spatial definition,” he points out. Small and medium flowering trees are what he uses for accents and seasonal interest.

CHOOSING A TREE

Whether you’re considering a leafy green tree, something flowering and decorative, or an evergreen, it’s not necessary to hire a tree relocator or spend hundreds of thousands of dollars to do it. There are plenty of healthy, young, ready-to-plant trees at your local garden center or nursery, as well as online.

Before you invest in one, take note of the types of trees you like best in your neighborhood and consider where on your property they would look and grow best. It’s also smart to talk with an arborist, the experts at the garden center or nursery, or your county extension office to learn more about what types of trees do well with the local soil and climate. The ultimate goal, after all, is to find a tree that meets your needs—for shade, wind protection, aesthetics, ease of care—as well as one that will grow and thrive where you plant it and be with you for a very long time.

Researcher Douglas W. Tallamy would like everyone to consider planting an oak. The author of The Nature of Oaks: The Rich Ecology of Our Most Essential Native Trees, Tallamy may be oak trees’ biggest fan, in part because of the great bounty an oak tree can produce: as many as 3 million acorns in its lifetime, with a mature tree dropping up to 700,000 leaves a year and providing a habitat for beneficial organisms. Add those figures to a tree’s standard benefits to the air, water, and soil, and you have a compelling reason to choose an oak sapling for your space. “A yard without oaks is a yard meeting only a fraction of its life-support potential,” he insists.

Brian Sawyer shared some suggestions for what tends to grow best in various parts of the country:

Northeast: White oak or any oak native to this zone, for shade and structure. (Note: Water oak and willow oak are not recommended because they produce lots of dead wood.) Magnolia stellata (or star magnolia), dogwood, or crab-apple trees for accents.

Southeast: Live oak for shade and sculptural interest, and crepe myrtle for seasonal interest and accent.

Northwest: Oregon white oak for shade and Douglas fir for defining space and screening. Sweetbay magnolia, cherry (varieties), or Pacific madrone trees for seasonal accent.

Southwest: Blue palo verde, white oak, or Texas ebony trees for shade and definition. Olive trees, mesquite, and saguaro cactus for accents.

Midwest: White oak or aspen trees for shade and definition. Crab-apple, Amelanchier, or red maple trees for seasonal interest.

BEFORE YOU PLANT

• Check to see if your town or city has any ordinances about planting or pruning trees.

• Consider where you want to plant the tree and what type of tree you’d like; research its potential height as well as the reach of the roots. Consult an expert, particularly for trees that you’re considering planting near your home, your septic tank, or other structures.

• Keep in mind that certain tree varieties may require a specific climate or type of soil; check with an arborist or other local expert.

Tree size is often measured by the diameter of its trunk, or caliper. The diameter is usually measured at six inches above the soil line on trees that are four-inch caliper or smaller. Slightly larger trees are typically measured at one foot above the soil line. When buying shade trees or evergreens for most residential properties, Sawyer recommends more established three-to-four-inch-caliper trees, since they look more mature more quickly. “If the homeowner has the time to wait years for smaller trees to grow or would like to save on costs, smaller-caliper trees can be installed,” he explains, adding that there is no difference in survivability.

One thing to keep in mind: Smaller trees tend to experience less root loss when they’re transplanted, according to the International Society for Arboriculture (ISA), so they establish themselves more quickly. Also, root loss in a larger tree can mean you’ll have to water it until its roots can support it. In other words, you may need to water a large tree for two or more years, while a smaller one could be self-sufficient much sooner.

THE BASICS

When to Plant. According to the ISA’s Trees Are Good website (treesaregood.org), the ideal time to plant new trees is during dormant seasons. That means in the late fall, after leaves drop, and in the early spring, before buds break. Planting when weather conditions are cool allows trees to establish roots in their new location before spring rains and summer heat cause the tops to start growing. However, healthy container trees, or plants that are balled and burlapped, can be planted throughout the local growing season. In parts of the country where trees grow year-round, such as tropical and subtropical climates, new trees can be planted anytime as long as there is sufficient water.       

How to Dig. It’s best to dig a shallow, broad planting hole two to three times wider than the root ball, but only as deep as the root ball. Keep in mind that the majority of a tree’s roots will develop in the top 12 inches of soil. To avoid air pockets, fill the hole by packing soil around the base of the root ball gently but firmly and watering periodically while filling in with soil. Trees Are Good doesn’t recommend adding fertilizer when you plant.

“Generally, when planting new trees, it is critical to backfill the root ball with suitable soil,” adds Sawyer, “and to plant the tree at the same grade it was grown at the nursery.” In other words, the soil should come to the same level it did before being dug out. If you purchased the tree from a nursery, the people there can determine if you need to add anything to the soil as you plant.  

The Trees Are Good site also recommends adding mulch to the soil surface of a newly planted tree to maintain moisture and improve soil conditions. Mulch also helps deter weeds and offers protection from extreme temperatures.

Care and Staking. Upkeep will vary based on the tree you’re planting. Some species require substantial watering until the roots are established, as well as regular mulching. Avoid pruning until the second or third year.

When a young or newly planted tree needs added stability, staking can help, particularly if it’s planted with bare roots, or in an open area that gets a lot of wind. Staking also adds balance when the crown, or top of the tree, is dense or too heavy to be supported by the trunk. “Some trees must be staked to prevent them from being pushed over by the wind,” adds Sawyer, who explains that a tree’s crown and foliage can act like a sail when the roots aren’t yet secure enough to keep it from toppling.

THE DEFINITIVE GUIDE

With almost 600 pages of authoritative information on individual species and their habitats, leaves, bark, flowers, fruit, and conservation status, Trees of North America (Audubon/Knopf, $39.95) is a comprehensive guide and look book for those who want to identify and appreciate what grows around them.

ONLINE RESOURCES

The Arbor Day Foundation website (arborday.org) has advice on tree varieties as well as planting and care. The site features a U.S. Hardiness Zone map to help determine what will grow in your part of the country and also sells trees and shrubs.

Awaytogarden.com is the website of Margaret Roach, the first garden editor of Martha Stewart Living and the current gardening columnist for The New York Times. The site offers helpful advice and information—“horticultural how-to and woo-woo”—about trees and shrubs, as well as ornamental and edible plants. Roach, who is also the author of several books about gardening, has a weekly online newsletter, as well as a weekly public radio show and podcast. Here are a few of the online nurseries she recommends:

• Broken Arrow Nursery (brokenarrownursery.com): This Hamden, Connecticut–based nursery sells a variety of trees and shrubs and also offers expert help and education.

• Keeping It Green (keepingitgreennursery.com): A family-owned Washington state–based retail nursery that features hard-to-find trees and shrubs as well as other rare plants.

• Mr. Maple (mrmaple.com): Nichols Nursery, of East Flat Rock, North Carolina, specializes in Japanese maples but also sells ginkgos, conifers, and more.

• Stark Bro’s (starkbros.com): Based in Missouri and in business since 1816, Stark Brothers focuses on fruit and nut trees and berry plants as well as landscape trees.

MODERN TREEHOUSES

A new trend in urban design puts nature front and center.

Location: Porta Nuova Gioia District, Milan

Designers: Diller Scofidio + Renfro, New York

Stefano Boeri Architetti, Italy

The Project: Known as Pirelli 39, it represents a new model of mixed-use buildings and sustainable design. One residential tower will be built with 18,300 square feet of vegetation planted on multiple floors, a vertical urban forest. The building will absorb 14 tons of carbon dioxide and generate 9 tons of oxygen annually. It will also produce enough energy to cover 65 percent of its needs.

Location: Vancouver, British Columbia

The Designer: Heatherwick Studio, London

The Project: This residential reinvigoration of the Vancouver skyline consists of two curvy, tree-like towers, with greenery, including terraces and planters, across the lower floors and timber accents throughout.