Town-dwellers tend to live cheek by jowl. About 18 years ago, I moved from the city to a house in the country on a 2,000-square-metre lot, backing onto farmland. But when I visit friends in town, I am reminded of how close together the lots are. Little wonder people plant trees to give them something other than the neighbours' drapes to look at.
Unfortunately, many trees eventually grow far too large for the available space. But there are plenty of trees suitable for even the smallest lot, trees that can be planted with the knowledge that they will neither outgrow their space nor require expensive tree surgery to keep them within bounds.
One of my favourites is a tree small enough for the pocket-handkerchief garden, found with rows of townhouses, and thrives even in poor, sandy soils. The 'Walker' Siberian peashrub (Caragana arborescens 'Walker', Zone 2) is grafted onto common peashrub stems and forms a narrow column about a metre wide at maturity. Because of its weeping habit, it gains very little in height, so if you want a two-metre-tall tree, this is the size to buy; mature width is about one metre. The branches on my 12-year-old plant now trail across the soil. Its small and almost threadlike leaves are pale green, with no fall colour, but in late May the plant is clothed in bright yellow flowers that resemble small sweet peas. The winter silhouette is most attractive, and its rounded top makes a good perch for birds.
A similar tree is the weeping white mulberry (Morus alba 'Pendula', Zone 4), with a pleasing umbrella shape that provides young children with a wonderful hiding place. It can grow to about two metres wide. Again, buy the size you need since it will gain little in height; 2.5 metres is as tall as it gets. The fruit, small and raspberry-like, are edible but will stain clothing and sidewalks, although the birds normally enjoy them before much damage is done.
The pagoda dogwood (Cornus alternifolia, Zone 3b) is a small, native tree that in nature prefers an acidic soil in light shade; however it is growing well in a slightly alkaline soil and full sun in my garden. It gets its common name from the branch tips that turn upwards slightly. This is a most attractive tree in late spring, with clusters of white flowers held just above the almost horizontal branches. The resulting fruit turn from green through red to almost black by late summer, at which time clouds of birds descend and strip the tree bare in a couple of days. It will grow to six metres tall by 7.5 metres wide at maturity, but it's slow-growing and will take more than 30 years to reach this size.
In warmer climates, consider the flowering and kousa dogwoods (C. florida, Zone 7, and C. kousa, Zone 6). Both have showy flowers in spring, good fall colour and edible, red fruit. The showy, white flowers are really four bracts, about 10 centimetres across (slightly smaller in the kousa dogwood), and are carried in multi-flowered heads above the branches. Alternative flowering dogwoods include 'Rubra', with pink flowers, and 'First Lady, with variegated yellow-green foliage. Both species prefer acidic soil in full sun; where widely planted, the flowering dogwood is prone to many pests-including dogwood borer and leaf miner-and diseases-anthracnose and powdery mildew among them. Despite this, I wish it were hardy in my zone. In Canada, both form trees about six metres tall and wide, although they can reach double that size in the southern U.S.