Trees are nearly everywhere, but often get little notice until they start dropping slippery fruit on the sidewalks, send clouds of whirlybirds into the pool or tangle themselves in the power lines. Being able to identify a tree--and assess its impact on your property--is an important skill for the homeowner or gardener to have. For others, it serves as a fun and relaxing hobby.
For many people, learning to identify plants is a pleasurable hobby, but it is not without its uses. Accurately identifying tree species can influence landscaping decisions. For example, when choosing where to build a fish pond, a gardener may wish to know if nearby trees will drop seeds that may clog the filter. Being able to identify trees in your yard also helps you to identify possible difficulties. For example, some species are prone to disease or rotting that could make them fall and cause major structural damage. Knowing which trees to monitor for signs of trouble is of value to the homeowner.
There are two basic types of trees, and determining which you have is a step in the right direction. Deciduous trees shed their leaves in the fall in order to prevent water loss and dehydration over the winter, when the ground is too hard for them to extract water, as well as to disrupt burgeoning pest populations. Evergreen trees never lose a full set of leaves at once and remain green year-round.
Narrowing down your type of tree can be as simple as borrowing a field guide from the local library, although universities and botanical organizations have developed excellent online tree identification resources as well. A dichotomous key is particularly useful when identifying trees. To use a dichotomous key, select which of two statements best describes the tree you are trying to identify. Dichotomous keys begin with broad classifications--deciduous or evergreen is a common starting point. Increasingly narrow the criteria until you are able to select a single species.
Leaf shapes vary greatly between tree species, making the leaves ideal subjects for closer inspection when trying to identify a tree. Most people observe the basic shape of the leaf--an oak leaf, for example, is very different from a pine needle--but more specific identification often requires more detail. You should observe the pattern that the leaf veins make, the shape of the leaf's edge, how the leaves are grouped and arranged on the branch and the size and color of the leaves. Put together, this information will help you to identify your tree.
Also consider the fruit, nuts, seeds or cones that the tree produces, as well as the tree's size, shape and bark. Once you have a possible identity for your tree, find as much as you can about the species and check your information against it. For example, if you live in Montana, it is unlikely that you have a tree in your backyard with a range that doesn't reach above Georgia. Consider geographical range, preferred habitat and any seasonal observations about flowering and leaf fall. If all of the data matches what you observe of your tree, you likely have your match.