Selecting an arborist - Ask Extension
Hello,
I would like to hire someone to help assess and prune trees on a property I recently purchased. Are there questions I can ask to help select...
Knowledgebase
Selecting an arborist #892886
Asked February 20, 2025, 1:42 PM EST
Hello,
I would like to hire someone to help assess and prune trees on a property I recently purchased. Are there questions I can ask to help select someone who uses environmentally friendly practices? Is there a registry of such companies?
Carroll County Maryland
Expert Response
We recommend searching for a certified arborist or a Maryland licensed tree expert, both of which will have similar levels of training. Consulting arborists in particular might be more likely to be impartial (when it comes to recommending pricy treatments, say) if they are not employed by a tree care company. Still, compared to the cost of most tree treatments or pruning jobs, having 2-3 arborists offer separate assessments would be relatively inexpensive and a valuable to determine what issues may be the most pressing. Not all tree decline or damage is treatable, but well-trained arborists/experts will know how to properly prune branches, look for girdling roots and other environmental sources of tree stress, and can help to diagnose any ongoing insect or disease issues.
If an arborist/expert does recommend treatment for a certain condition, they should be able to explain to you what pest/disease is responsible, how it's treated, and what pesticide (organic or otherwise) they suggest using and why. Plants don't heal from damage the way we heal from injury (though trees do have ways of discouraging wood decay), so intervention focuses instead on preventing more damage from occurring. Typically, serious pest or disease issues only arise after a tree is already injured or stressed by something in its environment (whether those symptoms are evident or not), so they are generally only a secondary issue.
If a dying or unsalvageable tree isn't risking harm to people or property when it eventually falls, we recommend keeping it for the wood's value to the ecosystem. A compromise if you can't keep a snag standing is to retain the downed wood to create a brush pile for wildlife, or to use wood chips as mulch over garden beds, veggie garden pathways, or similar uses. Sawdust can also be composted as another sustainable and environmentally-friendly way to deal with removed trees.
If you want to plant new trees that will eventually take the place of current trees in the canopy when they decline in time, you can usually do so any time without worrying about pest or disease issues plaguing older trees, since whatever stressed those mature individuals likely isn't going to also affect the new trees as long as they were selected for their tolerances of the site conditions. (For example, choosing species that handle wetter soils well if the area happens to drain poorly or be prone to flooding and soil saturation.)
Miri
If an arborist/expert does recommend treatment for a certain condition, they should be able to explain to you what pest/disease is responsible, how it's treated, and what pesticide (organic or otherwise) they suggest using and why. Plants don't heal from damage the way we heal from injury (though trees do have ways of discouraging wood decay), so intervention focuses instead on preventing more damage from occurring. Typically, serious pest or disease issues only arise after a tree is already injured or stressed by something in its environment (whether those symptoms are evident or not), so they are generally only a secondary issue.
If a dying or unsalvageable tree isn't risking harm to people or property when it eventually falls, we recommend keeping it for the wood's value to the ecosystem. A compromise if you can't keep a snag standing is to retain the downed wood to create a brush pile for wildlife, or to use wood chips as mulch over garden beds, veggie garden pathways, or similar uses. Sawdust can also be composted as another sustainable and environmentally-friendly way to deal with removed trees.
If you want to plant new trees that will eventually take the place of current trees in the canopy when they decline in time, you can usually do so any time without worrying about pest or disease issues plaguing older trees, since whatever stressed those mature individuals likely isn't going to also affect the new trees as long as they were selected for their tolerances of the site conditions. (For example, choosing species that handle wetter soils well if the area happens to drain poorly or be prone to flooding and soil saturation.)
Miri
