When trees grow naturally in the forest, the leaves fall around them, decay and form a good soil. The leaves also preserve moisture in the soil. On a lawn, however, the tree must compete with the grass for moisture and nutrients, and the leaves are raked up to prevent grass disorders, so that the successful gardener finds it wise to supply nutrients every two or three years. Feeding should be done when the ground is workable, in the spring or in the fall.

A difficult but worthwhile method of feeding is to strip the soil from an area all around the tree extending at least 2 to 3 feet beyond the outer branches, since the roof system extends this far. Apply stable or barnyard manure to this area, spreading it 3 inches thick and digging it in. Then firm the soil rake it level and return the sod.

An easier method is to drill holes over the same area, 12 to 18 inches deep and spaced about 15 inches apart. Fill each hole with a commercial fertilizer (made up of bone meal, tankage, peat moss, or humus) plus chemicals, in a formula containing 10% nitrogen, 6% phosphoric acid and 4% potash.

Water and Trees

Because of the transpiration of a tree, especially in the hot days of summer, lawn and specimen trees must be watered at least every 10 days in summer, to avoid trouble. Since the roots are deep, light watering won't do. The hose or sprinkler should be used for at least an hour. If the soil is hard packed, you can loosen it with a fork.

For a large tree, drive or bore a number of 1½ inch holes 3 to 5 inches deep and 3 feet apart, below the outer branches. Use a canvas hose or cover the hose with a gunny sack and let the water run. When planting new trees or small trees, if you put a few pieces of drain tile in the hole and put the hose in these, you can insure the water reaching the subsoil. Cover the drain-tile holes with stones to avoid evaporation.

Tips on Caring for Trees

Certain trees will not live long if a fill of soil is laid over their roots, or if a terrace of blacktop, outdoor fountains, brick or concrete paving blocks is laid over their feeding roots. Large, valuable trees should be protected with drain tile so that they will get water and air. The bark should be protected from dirt from a fill directly against it. You can buy metal tree wells, 3 to 7 feet across and 1 to 3 feet high, or build a masonry wall.

The wall can be capped with a circle of bricks or a low wall to make an extra seat on the terrace. If you have some surface other than sod or earth around the tree, see that it does not extend as far as the tree's outer feeding roots, and leave a circle of natural soil around the trunk. This can be planted. Care for your trees as injuries occur rather than wait to call in a tree surgeon and allow a weakened spot to remain untreated.

Remove all dead, decayed, diseased or injured bark. Do this by removing the entire limb, or, on a large limb or trunk, dig out the decayed matter, sterilizing and waterproofing the cut surfaces with creosote and liquid tar. White lead or paint are not as good to use as they will not seal when used on damp surfaces. Fill deep wounds with concrete. Use a pruning hook carefully, avoiding bruises.