Question
Hi,

I have a large oak tree in my back yard. Estimated age 100+ it seems to be in good health. Is there things I can do to keep it healthy? Or should I look for an expert to give me an idea on what might have to be done to keep it healthy? What should I be looking for in the tree expert category?

Thank you for you time,

Bob

Answer
The best thing you can do right now is fertilize the tree. A tree this old I would fertilize once a year. Use an all around fertilizer like 10-10-10 at the rate of 1 lb per inch of trunk diameter scattered around the tree under the branch overhang but not within 2 feet of the trunk. Water the fertilizer in good--apply just before a rain storm and you will not need to water. This will increase the health of the roots and in turn the overall health of the tree. The spring is the best time to apply the fertilizer. Make sure you do not use a fertilizer Called Weed and Feed. These contain a herbicide that will kill a tree.

IF the foliage is green and healthy and there are no large limbs dying there does not seem to be a reason to hire someone to treat your tree. IF you feel this is needed I would start with the local office of the State Forestry agency and ask one of their Foresters or Forest Health Specialist to come take a look. This is free service in most states. If you do hire a "tree expert" look for one that is a certified Arborist. Here is the web link to the organization that certifies Arborist. DO NOT use a tree service that removes trees they cut trees but have limited knowledge of tree biology. As long as there are not large limbs breaking and the foliage is healthy the tree is fine. In older tree decay fungi can enter the woody cells and over many years can expand up to the limbs and cause the large limbs to break and this could become a hazard if the limb can hit a object below. This does not sound like your situation so don't go and prune back the tree. This could harm the tree and the beauty. Your tree seems to be great as is.

http://www.isa-arbor.com/faca/findArborist.aspx