Choosing a maple tree
Challenging experiences with large trees shouldn't obscure the valuable features of the maple family, and most importantly, the desirable smaller species that are readily available. First, here are some considerations about growing trees in a cold climate. Most gardening books calculate mature growth statistics for hardwood plants on optimum growing conditions in the geographic centre of North America—and that could be a field in Zone 7. The growing season in Canada is considerably shorter, with fewer days of warm growing temperatures. We do have a healthy growing environment and can produce lovely trees, but they will almost always be smaller at maturity than gardening book figures for height and width suggest. (The exceptions to this are the true northern forest trees such as spruce, pine and hemlock.) Keeping that in mind, there are several desirable, small maples suitable for garden use; hybridzers have scaled down some of the large maples with similar reductions in root mass.
Placing your tree
Bigness is not a bad attribute in a plant, but there must be space for the bigness without consuming all in its shadow. The Norway maple, A. platanoides, would be happy in a meadow but makes a terrible obstruction when set down next to a house. Plant hybridizers have solved this problem (perhaps spurred by personal experience) and given us a columnar maple, A. platanoides 'Columnare', with a possible height of 12 metres and spread of four metres. (Sizes in this article are based on Zone 6.) The shape of 'Columnare' is compact and upright, with branches extending up rather than out. This is a reasonable size for a specimen lawn tree, or a string of trees set along a fence at least six metres apart. It would also find good use in the corner of a lot to block out sight of a telephone pole.
Red trees are useful for bringing colour to a green background in the warm months. 'Crimson Sentry' maple (A. platanoides 'Crimson Sentry') has deep purple foliage on a frame growing eight metres in height and five metres in width; it's hardy to Zone 4. Its pyramidal form is suitable for lawn placement or at the corner of a house. Both the 'Columnare' and 'Crimson Sentry' maples are generally lower-branched than other maples and this is always a plus in a specimen tree, preventing a hollow blank space under the limbs where grass won't grow. Nurseries sometimes mistakenly limb them up when very young, so search for one that has lower branches intact down to about one metre from the ground. Another scaled-down tree with lots of ornamental appeal is the variegated harlequin maple, A. platanoides 'Drummondii,' with light green leaves, each with a white margin. The harlequin maple makes a showy lawn specimen, growing to 11 metres with a spread of eight metres. All of the Acer platanoides hybrids are hardy to Zones 4 or 5.
If you've got a bit more space on a country property but don't want a full- size maple, 'Silver Queen' maple (A. saccharinum 'Silver Queen', hardy to Zone 3) is a more refined version of silver maple, growing to 16 metres with a width of 13 metres, still smaller than its species parent, which can grow to 18 metres high and 15 metres wide. The same can be said for 'Endowment' sugar maple (A. saccharum 'Endowment', hardy to Zone 4, which has a similar height of 17 metres and a narrower spread of six metres. 'Silver Queen' turns golden in autumn, while 'Endowment' turns orange-red.