Why are my Trees Slowly Dying?

If the trees leafed out normally in spring, looked healthy for weeks, and are now dying one by one instead of all at once, that usually points to an issue affecting individual trees rather than a problem with the entire planting. Here are the most common causes, roughly in order of likelihood:

1. Lack of Water (Most Common)

This is by far the biggest killer of newly planted trees.  Signs:

• Leaves wilt, curl, or turn brown from the edges.

• Entire tree slowly declines over several weeks.

• Soil is dry 4-6 inches down.

Keep in mind that even if it rains occasionally, the root ball may still be drying out. Newly planted bare-root trees often need 5-10 gallons of water once or twice a week during hot weather.

2.  Site Selection (Very Common)

• Not all trees are designed for all soils.     Trying to force a tree to grow in soil it isn't adapted to often leads to these results.    

  • Example:    Douglas & Fraser Firs in clay

  • Example:    White Pine next to a road where salt is used

3. Too Much Water

New roots also need oxygen.  Signs:

• Leaves yellow before turning brown.

• Soil stays wet for days.

• Tree never really puts on much new growth.

Poorly drained clay soils are especially prone to this.

4. Root Problems at Planting

Examples include:

• J-roots (roots bent upward)

• Roots left too confined

• Air pockets around roots

• Roots dried out before planting

These trees often appear fine initially because they're living off stored energy, then gradually fail as they cannot establish.

5. Herbicide Injury

Even a little glyphosate (Roundup), 2,4-D drift, or weed killer can damage young trees.

Signs:

• Twisted or cupped new leaves.

• Strange distorted growth.

• Damage often appears on scattered trees rather than every tree.

6. Animal Damage

Sometimes it's not obvious.

Look for:

• Rabbits chewing bark near the ground.

• Voles girdling stems under mulch.

• Deer browsing terminal buds.

• Mice living inside tree tubes.

Even partial girdling can kill a tree weeks later.

7. Planting Too Deep

If the root collar is buried:

• Trees often survive the first few months.

• Then slowly decline from lack of oxygen around the stem.

7. Heat Stress

A hot, windy summer can overwhelm a tree before its roots are established.

Symptoms:

• Leaves scorch.

• Branch tips die back.

• Tree declines despite occasional watering.