Why plant one spring flower when, by expanding the hole a bit and investing a few more minutes, you can plant thousands?

Consider that it's not much more work to plant a flowering tree than a six-pack of annuals, yet the benefits are incomparably greater. If well sited and given even minimal care, the tree should prove a permanent investment (for you, certainly -- your heirs may someday have to replant, but that's their concern).

In addition to longevity, a tree offers flexibility. A single tree can provide not only a veritable blizzard of early-season blossoms, but also a supply of colorful fruits in summer, vivid fall foliage, and an intriguing silhouette for winter still lifes.

A tree also furnishes living architecture around which you can organize your landscape. A single crab apple or cherry becomes a focal point for a vista or a buttress to anchor a bed or a border. A row of them becomes a wall to bound a garden room or highlight a path or a driveway. The irresistible attraction of such trees to the eye makes them a dramatic frame for a desirable view, or a matchless means of obscuring an unsightly one. A low-hanging moon echoed in a magnolia's pale, fragrant chalices is a Southern touchstone for romance. And who, honestly, could see past your dove tree (Davidia involucrata) -- set aflutter in mid-spring with handkerchief-like blossoms -- to notice your neighbor's rusty toolshed?

The key to all these rewards lies in two words: well chosen. Finding the right tree or trees for your garden involves careful consideration of a number of criteria.

First, of course, is climate. Some aspects of that can be moderated. For example, you can provide irrigation in an area with droughty summers. But winter cold is beyond a gardener's influence. That's why, for nearly 50 years, the standard tool for selecting regionally adapted plants has been the U.S. Department of Agriculture's map of hardiness zones. This divides the country into numbered zones according to the coldest temperature experienced locally in an average winter. If your garden lies in Zone 6 and a tree is listed as "hardy to Zone 6," that's a good indication the plant will survive in your backyard.

After climate, the fundamental considerations when choosing any tree are exposure and soil. Most flowering trees prefer an open area where they'll receive at least six hours of unfiltered sunlight every day. Fortunately, there are a number of woodland species such as dogwoods (Cornus spp.) and redbuds (Cercis spp.) that also will flourish in light shade, although in such situations they will bear fewer flowers. Most of the flowering trees available at nurseries and garden centers tolerate a range of soil types, but nearly all demand good drainage.

Something else to watch for when selecting trees is disease resistance. Inevitably, the most widely planted tree species have become targets for pathogens; plant breeders have responded by releasing resistant strains. The native flowering dogwood (Cornus florida) is prey to a fatal fungus throughout the northeastern and mid-Atlantic states. In those regions, it's only common sense to plant one of the fungus-resistant 'Stellar' hybrid dogwoods (Cornus spp.), such as 'Aurora,' 'Celestial,' or 'Stellar Pink.' Crab apples are subject to fungal and bacterial diseases, so it's imperative to plant a resistant cultivar such as 'Autumn Glory,' 'Molten Lava,' or 'Tina.' If the garden center you favor can't help you identify resistant cultivars, call a local cooperative extension.

Typically, a single tree provides only a couple of weeks of bloom. Its display, though eagerly anticipated and intense, is relatively brief. However, by matching an early-blooming star magnolia (Magnolia stellata), for example, with a less precocious crab apple or cherry and a late-spring-blooming dogwood or hawthorn (Crataegus spp.), you can extend the show's run from last frost until summer. Tuck in a sourwood (Oxydendrum arboreum) and a stewartia (Stewartia spp.) and you'll enjoy encores into mid-July -- and, best of all, revivals year after year.