One of the main reasons trees are important in a landscape is that they provide shade, which can cut energy costs. The Department of Energy estimates that the average temperature underneath a shade tree is 6 degrees Fahrenheit cooler than the surrounding air, and planting one near your house can reduce cooling costs by as much as 10 percent. The area directly underneath a shade tree, which can be as much as 25 degrees cooler than the surrounding blacktop, also is a refuge for delicate shrubs, grass and other greenery.
Trees also provide homes for birds, windbreaks for fragile plants and structures, and sometimes even fruit and nuts. Ornamental varieties bestow color and visual interest for your lawn and garden. None of these benefits come without an investment of time, but if you're in a hurry, you can minimize that investment by planting fast-growing trees. Some species can add 4 feet or more of height with every growing season, although 1 1/2 to 2 feet is more common.
Extremely fast-growing species often grow aggressively enough to be considered invasive, and because they shed bark and leaves with abandon, they can be messy. Even so, landscapers across the country have a number of safe choices, depending on the local climate and soil conditions.
Shade trees that grow quickly save more energy, according to DOE statistics. That's a good thing, but it's tempered by the fact that they usually have shorter life spans and are more vulnerable to wind and storm damage than those that take their time to mature.
Favorites for Northern Climates
The United States Department of Agriculture divides the country into approximately 13 plant hardiness zones. Zones 1 through 6 approximately encompass the northern half of the country. Not many fast-growing trees can grow there, but two common species can thrive happily.
- Paper Birch (Betula papyrifera) or River Birch (Betula nigra). These North American staples are famous for their peeling, paper-like bark. The leaves have a light green color in the spring which deepens in the summer and changes to yellow in the fall. They are widely adaptable to soil type and tolerates moist soil. The paper birch grows in zones 2 through 7, and the river birch in zones 4 through 9. They grow from 2 to 3 feet per year and reach a height of 70 feet with a typical spread of 35 feet.
- Quaking Aspen (Populus tremuloidies). Found in Alaska and as far south as central Mexico, stands of quaking aspen are a familiar sight in the Rocky Mountains and in the northeast coastal states. One of the few fast-growing trees adapted for Zone 1, the quaking aspen gets its name from the sound made by the leaves as they flutter in the wind. This tree loves moisture and will grow in most soil types. It grows about 2 feet every year to reach a maximum height of 50 feet and spread of 30 feet.
Fast-Growing Trees for Temperate Climates
Zones 4 through 9 encompass most of the central area of the United States, from the Great Lakes south to Tennessee and from the Atlantic seaboard to the eastern slopes of the Cascade and Sierra Nevada mountains. Landscapers in this region have the widest selection of species that grow quickly to provide instant shade. Here are four popular ones:
- Green Giant arborvitae (Thuja occidentalis). This evergreen with flat, scaled needles grows in a pyramid shape and is perfect for shaping into hedges to form a natural barrier or a windbreak. This Danish import, hardy in zones 3 to 7, requires little to no maintenance and is not particular about soil type. It grows up to 2 feet per year to a maximum height of 60 feet and a spread of 15 feet.
- Tulip tree (Liriodendron tulipifera). One of the tallest trees you can plant, a tulip tree can top out at 190 feet, although a height of 90 feet and spread of 40 feet at maturity is more common. Found in zones 4 through 9, it grows as much as 2 feet every year and features aromatic stems and tulip-like leaves that turn golden yellow in the fall.
- Pecan (Carya illinoinensis). Besides providing plenty of shade, this state tree of Texas starts to produce 75 to 100 pounds of nuts annually about 6 years after you plant it. It grows from 1 to 2 feet every year to reach a final height of 70 to 100 feet with a maximum spread of 75 feet. This tree, with its massive trunk, is not particular about soil type and grows well in zones 6 through 9.
- Red Maple (Acer rubrum). It doesn't take long for a red maple to reach its final height of 40 to 60 feet and adorn your landscape with its fiery red fall leaves. This iconic hardwood tree, which also features red flowers and red stems in the winter, can grow as much as 2 feet every year. It inhabits zones 3 through 9, and although it likes moisture, it is somewhat drought tolerant. Its leaves are toxic to horses.
Trees for Hot, Arid Climates
Zones 9 through 11, which encompass southern California and the rest of the Southwest as well as the Gulf states, are characterized by long, sunny days, warm temperatures and little or no frost. None of these conditions are challenging, but in the Southwest, the lack of moisture limits the choices of shade-giving trees, let alone fast-growing ones. Here are two candidates for dry terrain:
- Live oak (Quercus virginiana). Hardy in zones 7 to 10, the live oak is common in California because of its tolerance to drought and salty air. It grows especially fast when young, but as it matures, the rate slows to about 2 feet per year, which is still impressive. It provides plenty of shade, with a spread of 80 feet when it reaches its final height of 40 to 80 feet. This tree is not partial to soil type, and can withstand the occasional flood as well as drought.
- Honey mesquite (Prosopis glandulosa var. glandulosa). Native to the American Southwest and the California deserts, the honey mesquite grows in zones 6 through 10 and reaches a final height of 40 feet. Its roots spread out voraciously in search of water, so it needs plenty of room. It has thorny branches, flat, fern-like leaves and reddish fruit pods. This tree is highly drought-tolerant and is a good addition to your yard if you have a deer problem, because deer tend to stay away from it.
A fair number of fast growers are hardy throughout most of the country. Two are particularly iconic and do well in all but the most southern and northern climates:
- Eastern white pine (Pinus strobus). With its cluster of long needles, this tree turns any lawn into a mini forest and is perfect for anyone who wants a permanent Christmas tree on the front lawn. It grows in a conical shape, ultimately reaching a height between 50 and 80 feet with a spread of 20 to 40 feet. Growing in zones 3 through 8, the Eastern white pine can stand on its own or form a windbreak when planted side-by-side with other trees. It provides a home for squirrels and many types of birds. It grows at a rate in excess of 2 feet per year.
- Silver maple (Acer saccharinum). The silver maple bears the iconic leaves found on other maples, but the leaves are green on top and silver underneath. It grows in zones 3 through 9 at a rate in excess of 2 feet per year to reach a height at maturity of as much as 80 feet and a spread that often equals its height. This native species has fast-growing roots, so it should be planted at least 10 feet from walkways and buildings.
Both the Eastern white pine and the silver maple do best in moist acidic soil and have limited drought tolerance.