Planting & Maintenance
Selecting quality trees: Planting quality trees begins by selecting the right tree for the right location and
choosing vigorous, structurally sound trees from the nursery.
Digging the hole: A firm, flat-bottomed hole will prevent trees from sinking. Dig the hole only deep enough to position the root collar even with the landscape soil surface. Use a rototiller or shovel to loosen soil in an area three times the size of the root ball. This loose soil promotes rapid root growth and quick establishment.
Installing the tree: Remove soil and roots from the top of the root ball to expose the root collar; cut away any roots that grow over the collar. Cut any roots that circle or mat along the sides and bottom of the root ball. The root collar shall be even with the landscape soil after planting. Backfill with soil removed from the hole. Minimize air pockets by packing gently and applying water. Build a berm 4 inches tall around the root ball to help force water through the root ball. Enlarge the berm as the tree establishes.
Mulching: A layer of organic mulch, such as leaf litter, shredded bark, or wood chips, helps protect tree roots from temperature extremes and conserves soil moisture. Mulch also helps prevent grass from competing with the tree for water and nutrients. The mulched area makes it easier to operate mowers and weed eaters without hitting the trunk and compacting soil. Apply mulch to a depth of 3 to 4 inches (slightly thinner on top of the root ball).
Staking: The method of staking is dependent on a tree’s ability to stand on its own and the location of the
planting site. Staking is used to hold trees erect, allow the root ball to anchor, and protect the trunk from
damage by equipment. Stakes should be removed when the tree can stand on its own and the root ball is
anchored. Stakes should be positioned away from the tree and secured to the trunk at the point where the tree stands straight. Do not use wire or any strap that will girdle the tree or damage the bark. If a tree cannot stand straight on its own after staking, a splint stake tied directly to the trunk made of bamboo, spring steel, or a fiberglass rod may be used to straighten the upper trunk and/or leader. Avoid using square wood secondary stakes.
Consistent irrigation is critical for tree establishment.
- Apply about 3 gallons of water per inch of trunk diameter to the root ball 2 or 3 times per week for the first growing season.
- Increase volume and decrease frequency as the tree becomes established.
- Weekly irrigation the second year and bimonthly irrigation the third year should be sufficient for establishment.
- Once established, irrigation requirements depend on species, planting site, climate, and soil conditions.
- Irrigation devices should be regularly checked for breaks and leaks.
Reference: “CAL FIRE Standards and Specifications for Purchasing, Planting, and Maintaining Trees.” Developed as a project of CAL FIRE, Western Chapter of International Society of Arboriculture, California ReLeaf, and the Urban Tree Foundation. Copyright © 2011 Brian Kempf and Ed Gilman