How to identify the trees in your yard

Common planted yard trees and the check that separates them

These trees are planted across much of the US and are often missing from native-tree guides. The Virginia Tech Dendrology fact sheets cover each one, and they give the check that settles it.

Sources: Virginia Tech fact sheets for each species (crapemyrtle, Japanese maple, kousa dogwood, Callery pear, ginkgo, Leyland cypress) and Penn State Extension on Callery pear, which notes that "Bradford" is the most widely planted cultivar of Callery pear and that it has been widely planted as a street and ornamental tree since the 1960s. Penn State also gives the quickest look-alike test: flowering dogwood and viburnums have similar rounded leaves, but theirs are opposite and Callery pear's are alternate. The Bradford pear page covers that tree in detail.

The field method, applied to a yard tree

If the paper trail runs dry, use the same checks as for any tree, in the same order. The hub guide to identifying trees explains each step; for yard trees, three points matter most:

1. Opposite or alternate first. Look where leaves or buds join the twig. Among the trees in the table, Japanese maple and kousa dogwood are opposite; Callery pear and ginkgo are alternate. In eastern North America, a native tree with opposite leaves is almost always a maple, ash, dogwood or buckeye.
2. Ignore the range map. A range map rules out trees that don't grow wild near you, but planted trees grow far outside their native range. Virginia Tech marks ginkgo, Japanese zelkova, kousa dogwood and Leyland cypress as planted but "not known to widely escape cultivation", which is why wild-tree keys skip them.
3. Expect odd leaf colors and shapes. Purple, variegated, weeping or columnar trees are usually cultivars. Virginia Tech notes that some Japanese maple cultivars are so deeply lobed the leaf looks compound, and that leaf color varies with the cultivar.

A yard is also the easiest place to learn trees with children: the tree identification guide for kids turns these checks into short activities.

For yard trees, a landscape-plant database often beats a forest key. The NC State Extension Gardener Plant Toolbox describes 4,725 plants that grow in and around North Carolina, cultivated plants included, with photos and a glossary of identification terms. Many states' extension services publish similar landscape-plant guides.

Photo apps and communities for yard trees

A photo gets you a likely name quickly, and the shot list in how to identify a tree from a photo applies to yard trees too: whole tree, both sides of a leaf, the twig, the bark, and any flowers or fruit.

Two cautions are specific to planted trees. First, community sites treat them differently. On iNaturalist, an observation of a captive or cultivated organism can't reach "Research Grade", according to iNaturalist's help pages, so a yard tree marked as cultivated stays out of Research Grade however many people agree on it. Second, apps name species, not cultivars.

Tree Identifier, an iPhone app, names a tree from one photo using a cloud AI model, so it needs an internet connection. For a yard tree, its Care Guide tool adds watering, sunlight, pruning and seasonal notes for the species in the photo, and the follow-up chat under each result takes questions like "is this a Bradford pear or a native serviceberry?". It shows no confidence score, so check the name against the tree. If you allow location, the Tree Map keeps track of which tree is where, which helps on a large lot.

When to call an ISA Certified Arborist

You rarely need to pay anyone just for a tree's name. You do need a professional when the question is about the tree's care or safety. The International Society of Arboriculture's consumer site, TreesAreGood.org, describes an ISA Certified Arborist as a tree care professional who has documented knowledge of tree biology, diagnosis, maintenance and safety, and who must keep up continuing education to stay certified. ISA lists the jobs where an arborist helps:

• Pruning, for health, appearance or safety.
• Removal, when a tree is dead or dying, an unacceptable risk, an obstruction, crowding other trees, or in the way of new construction.
• Emergency care after storm damage, which ISA calls dangerous work.
• Planting, including choosing species that suit the spot.

An arborist on site will also name the tree. Before you hire one, use ISA's Find an Arborist directory to verify the credential. ISA notes that certification holders are held to a Code of Ethics, and that the listing is voluntary, so a certified arborist may not appear in it.

Ask your county extension office

For identification alone, the Cooperative Extension office in your county is the usual free option in the US. Ask Extension passes questions to Cooperative Extension and university staff and volunteers at participating land-grant institutions. Send several sharp photos (whole tree, leaf top and underside, twig, bark, fruit), your town, and the date.

Once you know what the tree is, you can estimate its age from its trunk or compare it with the native trees on the street. Keep the name with a photo; the next owner will thank you.