Five Rules for a Healthy, Long-Lived Tree

Planting a Tree

  1. Select only native or well-adapted trees for our area which have unblemished single trunks, firm rootballs and more branches than clear trunk (i.e. no “lollipop” specimens). See the plant list for specific recommendations.
  2. Locate large trees (over 60 feet at maturity) no closer than 20 feet from a building; medium trees (over 30 feet at maturity) no closer than 15 feet from a building; small trees (under 30 feet at maturity) no closer than 10 feet from a building; and all trees no closer than 15 feet from a telephone pole, fire hydrant or driveway.
  3. Dig a hole, no deeper than the root ball or container, but at least twice as wide as the root ball (preferably 3 to 5 times as wide).
  4. Place the root ball in the center of the hole.
  5. Backfill the planting hole with a mixture of native soil and a small amount (less than 15%) of compost.
  6. Cover the planting area with 3 inches of mulch in a 3 foot radius. Do not make a berm (a tall ring) around the trunk and do not push soil or mulch up around the trunk. Both of these common practices can cause rotting at the tree base.


Tree Drip Lines

The most active tree roots will be found in the top few inches of soil around the drip line (shown in red) of your tree. Protect the area in this zone during construction activities. This is the area to target with slow release fertilizer during the fall and with a soaker hose if irrigation is needed.

Establishing a New Tree During Drought

A prolonged drought is not the ideal time to plant a new tree. But if you’re diligent about watering appropriately, it can be done, and with very little additional water. Just water your new tree by hand using our 3-2-1 watering planBe sure to soak the root ball thoroughly every time you water. But also be careful not to over-water. That can stress a new tree just as much as not watering enough.

  • Time frame
    Watering Frequency
  • First four weeks
    3x per week
  • Second four weeks
    2x per week
  • Third four weeks
    1x per week
  • Following six months
    2-4x per month
Picture of Mark Peterson
Mark Peterson
Mark A. Peterson was a conservation project coordinator for San Antonio Water System before retiring. With over 30 years of experience as an urban forester and arborist, Mark is probably the only person you know who actually prunes trees for fun. When not expounding on the benefits of trees and limited lawns, you're likely to find him hiking San Antonio's wilderness parks or expounding on the virtues of geography and history to his friends.
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