Tree health can be difficult to determine, but checking your tree yearly may help you notice problems as they appear.

Is this year's growth much less than past years' growth? Fast growth does not mean good health, but a dramatic reduction in growth rate may be an indication of poor health.

Here's a tip: Look at the branch tips or tree top. A year's branches will typically be smaller in diameter and a different color.

Also, inspect the size, color and distribution of the leaves. Look at individual leaves, as well as the whole crown for differences between branches or sections of the crown.

Inspect the base of the trunk for damage from rodents or string trimmers.

Maintain a ring of mulch around the tree (the wider the better). Organic materials like wood chips and leaves are best. Wood chips will take longer to break down and, therefore, will not require replacement as often.

Newspaper kills grass. If there is grass in the area that needs to be mulched, put a five-page layer of newspaper over the grass and then add mulch on top. This will help keep the grass from growing up through the mulch.

Mulch becomes soil. There should never be more than four inches of mulch over the roots. Too much mulch or soil can prevent oxygen from reaching the roots.

Many professional landscapers have been incorrectly mounding up soil and heavy layers of mulch around the base of deciduous and evergreen trees. This practice seems to be catching on with more landscapers, but it is a practice that is a waste of money and harmful to the tree.

The tree trunk should always be above ground to where the root flares out at the soil line. Soil or mulch around the trunk encourages rodents and disease damage that can kill the tree. Also roots need to breathe and heavy mulch inhibits oxygen from getting to the roots.

When putting on new mulch always fluff up the mulch layer before adding new mulch. The entire mulch layer should not exceed two to four inches.

Topping is not pruning. Topping is the indiscriminate removal of branch ends. Topping injures and ultimately results in early failure or death of a tree.

If the end of the branch must be removed, cut it back to a side branch that is at least one-third (preferably one-half) the diameter of the branch being cut.

It is a myth that topping will make the tree easier to maintain. The truth is that topped trees can regain their original height quickly, often in two years. A topped tree will require more attention.

A wiser alternative to topping is careful selection and training of your young trees. Allow your trees to realize their full potential for health and beauty in the landscape.

"Growing Green" is contributed by Lehigh County Extension Office Staff and Master Gardeners. Lehigh County Extension Office, 610-391-9840; Northampton County Extension Office, 610-746-1970.