What Size Tree Do I Need? Understanding Tree Sizes for Your Landscape

Choosing the right size trees for your yard can add privacy, provide shade, and define your landscape, but how do you know what size trees to choose? Since trees come in an almost infinite range of sizes, knowing what factors to consider when selecting trees can help you make the right choice for your landscape. We’ll help you understand everything you need to know to pick the perfect tree sizes.

What Size Tree Do I Need?

Trees don’t come in standard sizes—you’ll find a near-endless range of tree sizes, from the tiniest dwarf willow to the largest majestic redwood. Selecting the right size tree for your landscape requires that you consider factors like how much available space you have, how large the tree will get at full maturity, how wide the canopy and root system are, and how much tree growth your property can support. 

Tree Size at Maturity

When you purchase a young tree at a nursery, it’ll be categorized by either caliper size (the diameter of the trunk) or pot size (the size of the container that houses the root ball). While those measurements will determine how much you’ll pay for a tree and give you an idea of how long it’ll take to establish, you’ll need to know how big the mature tree will get so you can pick the right size.

Small Trees

Small trees are under 25 feet tall at full maturity and a girth of up to 14 inches. Some types of small trees include magnolias, cherry trees, crepe myrtles, and Japanese maples. Small trees are a great choice if you have a small yard or to act as accents in plant beds or other landscaping features.

Medium Trees

Trees that grow to 25 to 40 feet tall and 15 to 19 inches in girth at full maturity are considered medium-sized. Some medium trees include weeping willows, black tupelos, serviceberries, and staghorn sumacs. Medium trees can act as privacy barriers and are ideal for average-sized yards.

Large Trees

Large trees are those that grow to more than 40 feet tall and more than 20 inches in girth at full maturity, like poplars, birches, oaks, and bigleaf maples. These trees can be the focal point of your landscaping and provide ample shade. Because large trees have wide-reaching root systems, they work best in large yards where they can be planted far from your home’s foundation.

How to Measure Tree Sizes

Tree height is measured from the ground to the highest branches, but that’s not the only measurement you should know. Tree girth, which is the diameter of the trunk, is also an important measurement. When you purchase a tree at a nursery, the caliper size is the current girth, but to measure a mature tree, wrap your tape measure around the trunk at about 4.5 feet up from the ground. This measurement is also called the diameter at breast height, or DBH.

Things to Consider Before Choosing Tree Sizes

Tree height and girth aren’t the only things to take into account when choosing what size tree to plant in your yard. Here are a few other things to consider when picking trees for your landscape. 

Budget

When you’re budgeting for the cost of landscaping, the cost to plant a tree can take up a significant portion of your budget. Smaller trees will cost less than larger ones, and younger trees are more budget-friendly than mature ones. Keep in mind, though, mature trees are both more expensive and harder to establish than young trees.

Spacing

Deciding what size trees you want and how many of them you’ll need also depends on your planned tree spacing. Large trees can’t be planted too close to other trees, so if you’re looking to plant a tree in the perfect spot with a large tree, it’ll need to be spaced far apart. Small and medium trees can be planted closer together, so if you want to add privacy with multiple trees, more moderately sized trees are a better choice.

Canopy Size

Tree canopy size is the measurement of ground that’s covered by the tree crown, or the total width of the branches and leaves when viewing the tree from above. Trees with large canopies provide more shade than trees with smaller canopies, so you’ll need to determine how much sun you want to block from your yard.

Root System Size

Root systems are a very important consideration when planting near a house. Tree roots can reach out underground several times the size of the crown, so you want to ensure the root system won’t grow into your foundation or interrupt underground utilities or septic fields. 

Growth Rate

Trees grow both in diameter and height every year, so you’ll need to factor in how long it’ll take for your tree to grow to full maturity. If you overplant young trees, you may find them quickly crowding each other as they grow, so always plant with the fully mature size in mind. 

What to Do if You Have the Wrong Size Tree

Planting the wrong size tree can result in unhealthy trees, overcrowding in your yard, damage from root systems, and more. Not sure who to hire to plant trees and ensure they’re the right size? A local tree planting service can not only advise you on the right trees to plant but can also tell you the best time to plant trees, plant a tree on a slope to help minimize erosion, and give your new trees the best chance at thriving into healthy, mature landscape features.