Arborists are best thought of as tree doctors. They know the ins and outs of tree care, and they know what tactics are best applied to treat and preserve health in different species of trees. Obviously, though, you can't just take your tree's temperature to tell whether it needs to see a tree doctor. So what are the signs that you need to make an appointment with an arborist? Take a look.
If your tree starts developing spots on its leaves, this is a sign it needs some help. Spotted leaves are almost always caused by either a bacterial or fungal illness. The spots are typically one of the early signs of disease, and if you don't take care of the tree at this point, the fungi may move into the tree's vascular tissues or other tissues, causing more serious harm and even death. An arborist can take a look and perhaps even take a sample of the spots to see what pathogen is to blame. They may then recommend spraying the tree with fungicides or even injecting its trunk with fungicides, depending on the pathogen to blame.
Multiple Dead Branches
A dead branch or two is nothing abnormal in a tree, presuming those branches are small to medium ones and not entire limbs. When you need to be more worried is if a bunch of branches or a whole section of the tree dies. This could be caused by an illness, or it could be the result of a crack or other physical damage that is preventing the tree from "feeding" those limbs. An arborist can not only figure out why the limbs are dead, but also remove them in a way that will cause the least harm to the tree.
A few insects are bound to land on your tree from time to time. But if your tree ever seems to be completely overrun by insects, or if you ever see what appear to be worms burrowing into the tree's bark, this is a sign of an infestation. There are several insect species that invade trees like this. Tent caterpillars are one. The emerald ash borer is another, although it only attacks ash trees. It's important that you can an arborist who can spray the tree and also apply fertilizer and other means to keep the tree healthy and strong.
If your tree is looking spotty, has dead limbs, or is attracting a lot of bugs, call an arborist. They're like doctors for your trees.