There are many things that can affect your trees these being anything from an insect infestation to a fungal infection in the bark etc. If caught early enough then they can be very simple to treat. Knowing the right treatment to use for each kind of problem is the main thing as they all have different ways of solving the problem.
Here are some examples of the problems you may encounter with your trees and ways to solve them:
- Insect infestation - There are many types of insect that will infest your tree and some if causing extensive damage can even cause the tree to die. Some of the different insects are aphids, bark beetles and various types of moth all causing different kinds of damage. Making sure you treat the tree correctly is vital when you have a problem such as infestation because if you don't the problem will persist. They each feed off different parts of the tree for example some will feed on the leaves some on the bark and some on the roots. Once you have identified the beetle that has infested your tree you will have to treat the tree accordingly you will be able to get this information from a local gardening store. If your trees seem to be prone to infestations then you may be best treating your trees each year with an insecticide suitable for the type of insects you are preventing from infesting your trees.

- Tree diseases - Each type of tree have various diseases they can get that are different to any other type of tree. The way to treat these diseases is to use the different chemical injections you can get for your trees as soon as the signs of these diseases show. Catching the disease as early as possible is the main thing because if left for too long many of these diseases can cause the tree to die. However, using these chemicals can harm the tree if the right amounts are not used so knowing the exact amount and where to inject them is essential. With there being so many variations of tree when it comes to identifying the problems your tree has you need to take note of the things that don't look right on your tree and either go online or see a tree specialist who should be able to tell you the exact problem your tree has. To prevent your tree from getting a disease regular pruning makes a great difference as a lot of trees get diseases through damaged branches or through damaged bark, pruning also just keeps your tree generally healthier.
If you are not sure on the processes used to prune, treat and maintain your tree then either ask a professional for their advice or get a tree surgeon in to do the work for you.