It’s not easy being a tree. This goes doubly for trees in urban landscapes. Air pollution, compacted soil, and road salt are just a few of the extra challenges that come with an in-town lifestyle. Worse still, much of that tainted soil and air is occupied by buildings, streets, sidewalks, power lines, and other structures that leave little space for branches and roots.
Amazingly, quite a few tree species are tough and compact enough to cope with these special challenges. Perhaps as remarkably, many of the best of these trees are still relatively rare in urban landscapes. If you’re looking to grow a tree in Brooklyn (or any other city), the choices range far beyond the ubiquitous littleleaf linden (Tilia cordata) and Norway maple (Acer plantanoides).
Outstanding Trees for Urban Landscapes
In place of Tilia cordata, you could try its smaller, more refined cousin, Kyushu linden (Tilia kiusiana). Rather new to American horticulture, this slow-growing 20-footer boasts a dense, teardrop-shaped habit; dainty, heart-shape leaves; and handsome, flaking bark. Kyushu linden prospers in sun to light shade in USDA Hardiness zones 5b to 8.
Shantung maple (Acer truncatum) is a well-behaved relative of Norway maple with lobed leaves that become flushed purple in spring, mature to rich green in summer, and turn sunset tints in fall. Its attractive gray bark provides winter interest. Height and width is 25 feet; favored conditions are full to part sun in zones 5 to 9.
American hornbeam (Carpinus caroliniana) has another common name – musclewood – which references its rippled blue-gray bark. Under whatever name, it’s one of the most picturesque eastern North American trees, with its muscled trunk, sinuously branched crown (to 30 feet tall and wide), and finely serrated leaves that go yellow in fall.
European hornbeam (Carpinus betulus) is a long-time (and larger) urban stalwart, usually seen as the upright-growing ‘Fastigiata’. It’s less hardy than American hornbeam’s USDA zones 3 to 9. Full to part sun; salt intolerant.
Chinese fringe-tree (Chionanthus retusus) is much underused. How can something this beautiful be this tough? Spectacular in late spring when covered with fleecy white flowers, Chinese fringe-tree carries its ornamental weight at other seasons with its shredding, cherry-like bark, bold oval leaves, and blue olive-shaped fall fruits. The yellow to rust-red fall color isn’t bad either. 20 to 30 feet tall. Full sun to light shade; USDA zones 5 to 8.
Cornelian cherry (Cornus mas) is actually a dogwood, despite its common name. A must for the urban edible garden, this multi-stemmed small tree is also essential for winter display, thanks to its clusters of acid-yellow flowers that precede those of forsythia. The cranberry-like fruits ripen in summer, and make for excellent preserves (they’re also good right off the tree).
Look also for the closely related but rarely offered Japanese Cornel dogwood (Cornus officinalis), which tends to bloom slightly earlier and often has pleasingly mottled bark. Both species are native to East Asia. 15 to 20 feet tall. Full sun to light shade; USDA zones 5 to 8; somewhat salt-tolerant.
American smoke tree, (Cotinus obovatus) has hazy, summer-borne seedheads that are not as showy as those of the much more common European smoke tree. But, the Southeast US native amply compensates with its smoldering fall color and scaly, silvery bark. Typically multi-stemmed and round-headed, it’s sometimes sold as a single-trunked specimen. The widely available cultivar ‘Grace’ – a hybrid with European smoke tree – offers equally spectacular fall color but a rather unruly habit. 25 feet tall. Full sun to light shade; USDA zones 5 to 9.
Osage orange (Maclura pomifera) is literally as tough as nails (just try hammering a nail into its rock-hard, close-grained wood), but it has never found a place in cultivated landscapes because of its spiny branches and large, messy, knobbly fruits. Thankfully, that’s all changing with the recent introduction of several lightly armed male cultivars (including ‘White Shield’ and ‘Wichita’). Now you can have Osage orange’s gleaming dark-green foliage and ironclad constitution without subjecting passersby to concussive fruits and clothes-rending spines. These cultivars grow quite rapidly to 30 feet or so. Sun to light shade; USDA zones 5 to 9; relatively salt-tolerant.
Peking lilac (Syringa pekinensis) is a close relative of the much more widely planted Japanese tree lilac (Syringa reticulata). Peking lilac surpasses it in its exceptional cold hardiness and its bronze, silver-flecked, often shaggy bark. Feathery clusters of white flowers deck its oval crown in late spring, and amber-yellow fall color occurs on some forms of this fine multi-stemmed or single-trunked tree lilac. Sun; USDA zones 3 to 7; relatively salt-tolerant.
Urban Tree Care
City trees appreciate a bit of extra coddling. Where soil is compacted or otherwise compromised, work several inches of topsoil (such as Fafard Premium Topsoil) into as much of the tree’s future root zone as possible. Although it’s tempting to plant a large balled-and-burlapped specimen with a several-inch-caliper trunk, smaller container-grown plants will establish more readily, and likely attain similar (or greater) stature in 4 or 5 years. Dig the planting hole to the same depth as the root ball (or shallower in heavy clay soil), and three (or more) times as wide. Spread a layer of compost in a wide circle around the newly planted tree, top with 2 to 3 inches of bark mulch, and water well, repeating when necessary (one or two times a week).
With good care, your new tree will repay your efforts by settling in quickly to its new urban home. Any one of these beautiful options will benefit your city landscape or street side, adding diversity and charm as well as welcome greening.