Setting a few ground rules with the contractor before work begins protects a tree's roots: a fence at the dripline, the ground beneath the outer edge of the branches, with no digging, parking, or stockpiling inside it, and tunnels instead of trenches for utility lines. Root damage can take years to show, so the rules are settled first.

Why does work near a tree harm it without touching the trunk?

Because most roots grow in the top 12 to 18 inches of soil and spread well past the branches, where excavation tears them, equipment crushes them, and stockpiled soil or paving cuts off their oxygen.

What should be agreed with the contractor before work starts?

The agreement covers:

• A fence at the dripline or farther out, left up until final grading
• No digging, parking, or stockpiled soil inside the fence
• No grade cuts or added fill within the dripline
• Pruning saw cuts on roots over 2 inches across

How close can a utility trench come to the tree?

Open trenches stay at least this far away, by trunk diameter at chest height:

• Under 6 inches: outside the dripline
• 6 to 9 inches: 5 feet
• 10 to 14 inches: 10 feet
• 15 to 19 inches: 12 feet
• Over 19 inches: 15 feet

Closer to the trunk, utility lines are tunneled 3 to 4 feet deep.

What care helps the tree once the crew leaves?

Deep watering in dry spells, 2 to 4 inches of mulch kept off the trunk, and no fertilizer for a year or two on a badly stressed tree. To stretch the time between soakings, Hydretain Root Zone Moisture Manager is applied through a hose end sprayer and watered in.

Frequently Asked Questions

Which trees are most sensitive to root damage?

Oaks, hickories, honeylocust, Kentucky coffeetree, horse chestnut, redbud, serviceberry, and all conifers are rated very sensitive. Silver maple, river birch, willow, cottonwood, and poplar tolerate root loss fairly well.

Should the crown be pruned after roots are cut?

Not automatically. Only weak or dead branches are removed, and only while soil moisture is adequate.

When should trees marked for removal come down?

Ideally while the trees being kept are leafless. Taking out neighbors in full leaf can suddenly expose the remaining trees to sunburn.

Is it ever better to remove a tree before construction?

Yes, when severe damage is likely. Removing it beforehand costs less than taking down a declining tree after the work is finished.

When can a tree be fertilized again after construction?

Once the tree has recovered, usually a year or two after the work. From that point, TreeHelp Premium Fertilizer feeds slowly through the season, with one 3.3 pound bag treating a mature tree.