Mulching can benefit both young trees and older, well-established trees.  Mulch keeps moisture in the ground to help newly planted trees become established, and prevents grass and weed growth around the base of a tree.  Organic mulches, such as bark mulch, wood chips, and composted leaves also add nutrients to the soil as the mulch breaks down.  Spread mulch in a circle with a 2 to 3 foot radius around the tree, and not more than 2 to 4 inches deep.  The mulch should not touch the trunk of the tree, but rather be kept several inches away.   Loosen the mulch with a rake or hoe once a year and add fresh mulch to maintain a 2 to 4 inch layer.

Watering a tree after planting is a simple but important step to ensure that the roots will be able to provide sufficient moisture for the tree to grow.  Many nursery grown trees, especially when they are balled and burlapped, lose most of their roots during the nursery digging and transplanting process.  These trees require extra water to make up for the lack of feeder roots that can take up water.  Newly planted trees should be watered with about 10 gallons of water per week unless at least one inch of rain has fallen recently.  Established trees also require extra watering during periods of drought.  If possible, water the entire area covered by the root system, which could easily extend beyond the dripline on established trees.  The roots will be better able to take up the moisture if watering is done slowly and gradually rather than all at once. Fill buckets or milk jugs that have small holes in the bottoms (or gator bags) and set them out across the root zone for slow watering.

Pruning should be done to control a tree’s shape or to remove damaged branches.  Pruning can also be done to ‘elevate’ a tree, where the lower branches are removed to allow persons and vehicles to pass underneath.  Improper pruning can often lead to more problems than the pruning had intended to solve.  Never remove more than 25 percent of a tree’s crown in one year.  Winter or early spring is usually the best time to prune most trees, except oaks and honeylocusts which are more susceptible to disease in the spring.  Some trees (maple) may bleed if pruned during the spring.  The direction of branch growth can be controlled by pruning a branch back to a bud.  The branch will generally continue to grow in the direction that the bud is pointing.  Branches are best removed by making three successive cuts.   The first cut is made underneath the branch several inches away from the branch collar.  This cut prevents the branch from tearing the bark as it falls.  Cut about 1/3 of the way through the branch.  The second cut, just outside of the first cut, is made all the way  through the branch.  The third cut is made close to the branch collar all the way through the branch.  The branch collar will then grow over the wound to protect the tree from decay.  Wound dressings are not recommended, and could actually harm the tree by trapping moisture in the cut.

Fertilizing a tree provides supplemental nutrients which are necessary for the tree’s growth.  Although many different nutrients are used by a tree, only nitrogen (N) is usually deficient.  Nitrogen maintains the green leaf color and is required for twig growth.  Many commercial fertilizers also contain phosphorus (P) and potassium (K).  Phosphorus is important for root growth and flower production.  Potassium is used in the manufacture of food for the tree.  The best time to apply fertilizer is during the fall or winter.  The nutrients will then become available to the tree during the following growing season.   Do not fertilize a newly planted tree the first year.  The availability of nutrients for uptake by a tree can be determined by the acidity or alkalinity (pH) of a soil.  A soil test is recommended to determine the nutrient status and pH in a soil.  Over application of fertilizer can be harmful to the tree and to nearby streams.  Other nutrients, and organic matter, might have to be added in harsh soils.

Even if your tree has been adequately mulched, watered, pruned, and fertilized, periodic inspections of the tree should be made to determine its overall condition. Check for the tree’s shape, normal growth and leaf size, and any signs of insects or disease.  If stakes and wire were used to support the tree after planting, they should be removed one year after planting.  The wire could otherwise become ingrown into the tree and interfere with the normal flow of water and nutrients just inside the bark.