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10 City Trees for Urban Landscapes and Street Sides

Littleleaf lindens
Littleleaf lindens (Tilia cordata) are common street trees for urban areas.

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

Chinese fringe-tree
Chinese fringe-tree (Chionanthus retusus)

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
American hornbeam (Carpinus caroliniana)

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.

Corenlian cherry fruit
Cornelian cherry (Cornus mas) fruit

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 fruit
Osage orange (Maclura pomifera) fruits do not exist on new all-male varieties.

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 Fafard Premium Topsoil packof 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.
Variety of trees

Summer Tree Care

Tree with houses in the background
Summer tree care helps landscape trees look great all season.

Trees are the ultimate givers, offering summer shade, protection from wind, and cleaner air.  They also beautify our landscapes, often providing food and serving as habitats for wildlife.  But, even in the face of all that generosity, we often ignore them.  Our trees deserve better, and summer is a good time to turn over a new leaf and focus on tree care.

Summer weather stresses trees.  Drought is hardest on very young or old specimens but ultimately affects them all.  Storms threaten stability and bring weak or diseased limbs crashing to the ground.  Lawn and garden equipment damages tree bark, while untreated pests and diseases can decimate entire communities of once-healthy trees.  Fortunately, it takes only a little observation and a bit of care to help trees withstand those stresses, enabling them to continue giving for decades to come.

Inspect Your Summer Trees

Tree with white blossoms
Healthy trees will have vibrant foliage, growth, flowers, and fruit.

Start by taking a good look at all the trees on your property, using binoculars, if necessary, for large trees.  Check for limbs that are dead, cracked or otherwise compromised.  If damaged trees are large or need anything more than minor pruning, call a tree expert to perform the work.  This may seem expensive, but corrective pruning helps trees withstand summer windstorms and prevents potential property damage and personal injury caused by falling limbs.

 Check Trees for Pests and Diseases

Tent caterpillars on the upper branches of a black cherry tree
Tent caterpillars on the upper branches of a black cherry tree.

If you seek expert advice or help with pruning, ask an arborist or tree surgeon to check for pests and diseases.  Pernicious pests like the emerald ash borer and the Asian long horned beetle can wreak wide-scale havoc, killing scores of trees in a single area, if infestations aren’t promptly controlled.  Bag worms, fall webworms, and early season tent caterpillars can cause significant damage to foliage, which stresses trees. Wasting diseases, like verticillium wilt in maples, can sometimes be arrested, if affected trees are treated in time.

If you don’t have expert help, check with your local cooperative extension agent to find out which pests and diseases are most prevalent in your area. Some municipalities employ professional arborists who can also provide this information. Take a good look at tree bark and foliage for telltale problem signs.  Follow the expert’s advice on treatment or prevention of pest or disease outbreaks.

Water Summer Trees Wisely

Silver watering can
Summer tree irrigation is especially important for newly planted trees.

All trees need regular water, though mature specimens, with broad, healthy root systems are best able to tolerate extended droughts.  Young trees are a different story and need water every few days if rainfall is sparse or nonexistent.  The best way to water tree roots is low and slow irrigation, positioning the water source close to the ground.  This means soaker hoses circling trees’ bases.  For newly planted and very young trees, property owners can also buy “tree bags”, water-holding, heavy-duty plastic bags constructed to wrap around the trunk.  Small holes in the bottoms of the bags allow water to seep slowly to the roots, a process that takes several hours, depending on the size of the bag.  Refilled every day or two during drought spells, the bags can be lifesavers for immature trees.

Protect Trees from Mechanical Injury

Tree rings with wheelbarrow
Tree rings protect trunks from mechanical injury, but beware “mulch volcanos”!

Power string trimmers are great garden time savers, allowing landscapers and homeowners to keep bed edges neat and tidy.  But repeated blows to trees from trimmers can penetrate tree bark to the point where young trees may die.  Trimmer injuries may not kill older specimens outright, but create entry points for damaging pests and diseases.

The best way to separate trimmers and tree trunks are to mulch tree rings around trees, a technique that also conserves soil moisture and keeps weeds under control.  Spread high-quality mulch in a circle with a radius of at least 2 feet around the base of the tree.  Keep the depth at about two to three inches and do not let the mulch touch the trunk.  So-called “mulch volcanos”, where large amounts of mulch are hilled up around tree trunks, contributes to the spread of bacterial and fungal diseases.  Always aim to create a moderately deep “mulch doughnut”, rather than a mountainous mulch “volcano”.

Tree Planting and Fertilization

Fafard Premium Topsoil packTree planting is also best done in spring or fall, when weather conditions are less likely to stress young saplings.  However, if you must plant in summer’s heat, “water in” the tree by filling the planting hole part way with water before installation.  If the surrounding soil is poor, thin or compacted, fill in around the tree’s root ball with a mix of the removed soil and an equal amount of high-quality, fertile planting material, like Fafard® Premium Topsoil.  Once the tree is planted, remember to water well, especially in hot, dry weather.

It is best to fertilize trees in the spring, just before the first flush of growth.  This growth slows down in summer, so the season is not optimal for fertilization.

Sitting under a tall shade tree with friends, family or just a good book is one of the best ways to spend a summer afternoon.  Timely summer tree care is the best way to ensure that you will continue to enjoy that experience for many years.

Planting a new tree with a child
Plant new trees in spring or fall. Spring planted trees need extra care through summer.

Growing Eggplant in the Garden

Eggplant in various sizes and colours
Eggplant come in many shapes, sizes, and colors.

Eggplant is a staple in African, Mediterranean, Middle Eastern, and Asian cuisines, where growing temperatures are hot. Think beyond the standard purple varieties you find at the grocery store. Green, ivory, rose, and magenta types of various shapes and lengths exist, and the best are mild and have few seeds. Some are even ornamental. The biggest challenge to growing them is battling a few common pests. Once these are tackled, plants will reward you with lots of fruits for Szechuan eggplant, eggplant Parmesan, ratatouille, and baba ganoush.

African Eggplant

Indian 'Petch Siam'
The Indian ‘Petch Siam’ is a round, green eggplant favored for curries.

There are many unique types of eggplant grown in Africa, most being variants of the African eggplant (Solanum aethiopicum). The ‘Striped Togo’ is an ornamental variety of African eggplant sold in the US, which has small, egg-shaped fruits of electric orange with green stripes. They are edible but have a very strong flavor, so most opt to add stems of the pretty fruits to late summer and fall arrangements. ‘Turkish Orange’ (Solanum aethiopicum ‘Turkish Orange’) is another African variety with fruits that age to brilliant orange red. These are larger and edible when green.
Several African eggplant varieties are popular in Brazilian cooking and classified as Gilo (or Jiló) eggplant. They are small, bitter, harvested green, and include the small, pear-shaped ‘Comprido Verde Claro’, and round, more bitter ‘Morro Redondo’. Due to limited demand, these unusual eggplant have yet to be adopted by American seed companies, so they are hard to find in the US.

Mediterranean and Middle Eastern Eggplant

'Black Beauty' eggplants
‘Black Beauty’ is the most common eggplant variety grown in the US.

The common eggplant or aubergine (Solanum melongena), is the most familiar eggplant to western palates and gardens. It has been grown and selected for hundreds of years in southerly regions of Europe and throughout the Middle East. One of the best from the Mediterranean is the classic Italian heirloom ‘Rosa Bianca’, with its broad, short, mild fruits covered with thin, lavender and cream skin. The French heirloom ‘Ronde de Valence’ is another unique but delicious eggplant that is deep purple, grapefruit-sized, and almost perfectly round. For a large-fruited, heat-tolerant eggplant, choose the Iraqi variety ‘Aswad’ (meaning “black” in Arabic), a new offering from Baker Creek Heirloom Seed. Its dark, pleated fruits can reach a massive 3 lbs.

Eggplant 'Gretel'
Eggplant ‘Gretel’ (Image by AAS Winners)

One American eggplant with a classic pear shape and purple-black skin is ‘Black Beauty’. The 1902 heirloom from Burpee has large fruits with good flavor. Two more American varieties include the AAS winners ‘Gretel‘ (2009 winner), which is petite and has white fruits, and the compact ‘Fairy Tale’ (2005 winner) with its small stature and white-striped purple fruits. Both are very productive and good for small-space gardening.

Asian Eggplant

‘Pingtung Long’ eggplant

Eggplant varieties from Asia are noted for their elongated shape, low seed count, and mild flavor. Many were bred in Southeast Asia and have an unusually high tolerance to heat and drought. The brilliant purple ‘Machiaw‘ is a tender, mild, thin-skinned variety that always produces well. For exceptional heat tolerance, choose ‘Pingtung Long‘ an heirloom from Taiwan that produces loads 16″-18″ long magenta fruits through the hottest days of summer. The dark purple ‘Orient Express‘ is an early, tender variety popular in many gardens. Finally, for something more unusual, try the Indian ‘Petch Siam‘, a small, green, striped eggplant favored for curries.

Growing and Harvesting Eggplant

Flea beetle damage on an eggplant leaf.

Growing eggplant is not too complicated. Provide them with full sun, warm summer days, good soil with adequate drainage, a little vegetable fertilizer, and water, and they will grow well. (Amend their soil with Fafard Garden Manure Blend before planting, and they will grow even better!) The biggest challenge to their success are two common pests: flea beetles and Colorado potato beetles.
These two pests will destroy plants if given the chance. Flea beetles are tiny, shiny black, and invade in large numbers, hopping from leaf to leaf sucking the juices from the foliage, leaving behind a mass of pock marks. (Read more about these pests here.) To reduce populations, clean old plant debris in fall (where these pests overwinter), till beds in spring, and plant eggplant in late spring to early summer to avoid spring hatches of this pest. Spraying with insecticidal soap or pyrethrin sprays will kill adult beetles and protect plants from summer damage.
Striped Colorado potato beetles lay masses of yellow eggs on the undersides of eggplant leaves in spring. Brownish orange larvae emerge that aggressively feed on leaves. As they grow larger, they cause more damage and can completely defoliate young eggplants. The best protection is to inspect plants for egg masses and remove them on sight. The beetles and larvae are also easy to remove by hand. (Learn more about these pests here.)
Most fruits are ready to harvest when they are fully colored and firm to the touch, while giving slightly when pressed with a finger. Fruits that are too old begin to turn yellow. At this point, they are too seedy and strong to eat.
Eggplant are delicious, easy to grow, and make a great addition to any summer garden. Add them to pasta sauces or your favorite eggplant dishes! They also freeze well for winter storage.

Orange ‘Striped Togo’ African eggplants in a harvest bowl with tomatoes.