How to fertilize trees

Is the tree showing any signs of a nutrient deficiency, and are there any fertilizers that are being added during other landscape-management practices and, if so, how much?

trees will tell you if they need more nutrients. The most common sign is yellowing of the leaves on deciduous trees.

This can be a symptom of several nutrientdeficiencies. To pinpoint the culprit, it’s best to have a soil test done. An important step in any good fertilizer program, soil tests should be done every year or two. They can tell you about the nutritional elements that are available in your soil and about the nutrients your plants may require.

Once you know what the soil is lacking, consider what else is being fertilized nearby. Grass and trees share root zones, so whatever fertilizer you are applying to your turf is being applied to your trees as well. Be sure to factor this into your overall tree-fertilization program.

One way to fertilize a tree is to broadcast granular fertilizer evenly over the area under the tree, extending to the drip line. Be sure to apply the fertilizer to moist soil or water it in immediately after application to avoid fertilizer-burn damage to the roots.

Source : The ABCs of fertilizing trees