How Close Can a Tree Be to Your House in Spokane, WA?

The short answer: most trees within 10 feet of a house need a closer look

The generally accepted safe distance is 10 feet for small trees and 20 feet or more for large trees, but height, species, soil, and trunk lean can make a tree dangerous at any distance. In Spokane, where many lots have mature ponderosa pines and Douglas firs that reach 80 to 120 feet, a tree 15 feet from the house can still be a threat if its roots have lifted the soil or if the trunk has started to lean. The 10- and 20-foot figures are starting points, not guarantees. A tree that is 30 feet away can still drop a limb on your roof if the limb is long enough, and a tree that is 5 feet away may be fine if it is a small ornamental with a healthy root system. The only way to know for sure is to look at the whole tree and the ground around it.

Why height and distance tell you more than a single number

The taller the tree, the farther it can reach when it falls. A 100-foot tree can strike a house 100 feet away if it falls in that direction, but most trees fall within one and a half times their height. That means a 100-foot tree could hit a house 150 feet away under the right conditions. So why do we talk about 10 and 20 feet? Because those numbers describe the zone where roots, branches, and the trunk itself are most likely to cause damage without a full fall. Within 10 feet, roots can crack a foundation, a driveway, or a sewer line. Within 20 feet, a large limb can hit the roof. Outside those zones, the risk does not disappear, it just changes. A tree 50 feet away can still drop a branch on a power line or a car, and a tree 100 feet away can still fall on the house if the wind is strong enough and the soil is wet. Distance alone never tells the whole story.

What we look at before we say a tree is safe or not

We look at four things: the trunk, the roots, the canopy, and the ground. A trunk that leans more than 15 degrees from vertical is a warning sign, especially if the lean is new. A trunk with a cavity, a crack, or fungal growth at the base is weaker than a solid one. Roots that have lifted the soil, cracked a sidewalk, or created a visible mound on one side of the tree mean the tree may be rocking. A canopy that is thin on one side, or that has dead branches larger than your arm, is a hazard. And the ground itself matters: in Spokane, our clay-heavy soils hold water in winter and spring, which can make a root plate less stable. A tree on a slope above a house is more dangerous than one on flat ground, because gravity and water both push downhill.

The species matters as much as the distance

Some trees are more likely to fail than others. Ponderosa pines, which are common in Spokane, have a deep taproot when young but can become top-heavy as they age, and they are prone to dropping large limbs in wind and snow. Douglas firs have shallow root systems that can be undermined by wet soil. Cottonwoods and willows are fast growers with weak wood, and they often have multiple trunks that can split. On the other hand, a mature oak or a maple with a single trunk and a healthy root flare is usually more stable. If you have a fast-growing species within 20 feet of your house, it deserves a closer look than a slow-growing one at the same distance. The species also affects how far roots spread: some roots travel two to three times the height of the tree, so a 60-foot tree can have roots 120 feet out, which means it can affect a foundation even if the trunk is 30 feet away.

A seasonal checklist for Spokane property owners

Use this checklist to time your inspections. In Spokane, the ground is wettest from late fall through early spring, and that is when root plates are most likely to move. Windstorms are most common in fall and winter, and heavy snow can load branches in December and January. Summer drought can dry out soil and make it shrink, which can also destabilize a tree. Here is what to do and when:

• Fall (October to November): Look for new lean, cracks in the soil, or mushrooms at the base before the ground gets saturated. Check for dead branches in the canopy.
• Winter (December to February): After a windstorm or heavy snow, check for broken branches, lifted soil, or a trunk that has shifted. Do not stand under a tree that is shedding limbs.
• Spring (March to May): Look for heaving soil, exposed roots, or a new tilt after the freeze-thaw cycle. This is a good time to inspect the root flare.
• Summer (June to September): Watch for sudden leaf drop, thinning canopy, or bark falling off. These can signal internal decay.

What to do if you think a tree is too close

If a tree is within 10 feet of your house and shows any of the warning signs above, do not wait. Call us at (509) 555-0123 to schedule an on-site look. We will tell you what we see and what options exist. Sometimes the answer is removal. Sometimes it is pruning, cabling, or root management. Sometimes the tree is fine and you can leave it alone. We cannot give you a safe distance over the phone because the answer depends on the tree in front of you. What we can do is walk your property, check the trunk, roots, and canopy, and give you a written assessment. If you are not ready to call, take photos of the trunk base, the lean, and any cracks in the ground, and note when you first noticed the change. That information helps any conversation about the tree.