Some points with regard to tree establishment and maintenance.
August 2001
Jean Thomsin, Orange County Master Gardener



· Because of our clayey soil more often than not newly planted young trees have trouble to establish a strong root system.

· As an example Drake Elms (Ulmus parvifolia 'Drake'), used as street trees in Cypress Isles, often topple during strong rainstorms and generally are not doing well.

· Better suitable for our not well draining and often compacted clay soil are the Live Oak (Quercus virginiana), the Winged Elm (Ulmus alata), the Laurel Oak (Quercus hemisphaerica), the Red Maple (Acer rubrum) and the Allee Elm (Ulmus parvifolia 'Allee')

· It is advisable to plant smaller trees (trunk diameter 2" or less measured 6" from the root ball) rather than larger trees. This will result in a shorter time of establishment and a better chance of survival and they are cheaper.

· In a well-drained soil a new tree should be planted with the root ball level with the surrounding soil. However, in not well draining clay soil and/or compacted soil the top quarter to third of the root ball should be planted higher than the surrounding soil and irrigation managed accordingly. Dig the planting hole deep enough to penetrate the clay layer and refill with soil mixture such that one-third of the root ball is higher than the surrounding soil. After planting, mound soil to create a gentle slope down from the top of the root ball. The planting hole and resulting mound should be at least five times wider than the root ball.

· Proper irrigation during establishment is of utmost importance. It is even more important than fertilization. A small tree (diameter less than 2") needs water every day for two months, than every other day for 3 months and than once per week. Planting a larger tree requires watering during periods twice as long. (another reason to plant small trees)

· Many healthy trees do not require staking after planting. However, if anchor stakes are required 2-3 stakes should be used which are driven at least 24" into the ground. Use wide rubber-like material as wrap around the trunk above the base of the lower branch. Wraps and stakes should be removed within a year after planting.

· Apply mulch 2 to 3 inches deep in a circle around the trunk. The diameter of the circle should be 2 feet for each inch of trunk diameter. So a 2" trunk requires a circle of mulch with a 4 feet diameter. Mulch around the trunk will help establish the tree quickly without competition of other plants, especially turf grass.

· Fertilization is desirable. Give new trees 4 to 6 weeks after planting a small application of slow-release fertilizer (30-50% slow-release Nitrogen) and than two to three times per year for the following 3 years or so. Two of the annual applications are normally scheduled for March and September. The third application can be made during the summer. These applications should be applied to the surface of mulched and un-mulched areas extending out from the tree's trunk to about 1 ½ to 2 times the canopy's diameter. An example of the amount of fertilizer to be used in an annual application is e.g. 0.24 lbs. (= 7.5 tablespoons) of 12-4-8 (N-P-K) fertilizer for a canopy of 4 feet and an area of 1.5 x 4 = 6 feet diameter. Many fertilizers are formulated for use on lawn grasses. Some of these, known as weed-and-feed fertilizers, may contain a herbicide that can damage trees. It is best to not use these close to young trees. Once trees are well established (3 to 5 years after transplanting) they will not need additional fertilizer if they are growing in a landscape where turf and shrubs are fertilized.


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This page was updated 8/23/2001