Tree health is a concern for everyone who cares about natural spaces or spends time in or around trees. Trees can be a powerful and inspirational presence, as well as an important part of the ecosystem and our lives. Strong trees feel good to walk under, provide shade during the summer heat, and reduce air pollution. They help adjust Earth’s climate, produce oxygen through photosynthesis, provide homes for animals, and prevent erosion by holding soil in place with their roots that are built like anchors into the ground.
Threats to trees can come from insect infestation, disease, and physical injury. These are not limited to urban areas but are found in forests, woodlands, and even home landscapes. Tree health is affected by a wide range of factors, including individual species’ biology and genetics, the environment in which it is found, and its location within that environment (such as exposure to sun and wind).
1. Observable Yearly Growth
Most trees have an observable yearly growth pattern. The tree’s annual rings can help determine its age, show the timing of when it was planted or transplanted, and indicate when a tree is stressed. You can count the number of rings on certain parts of the tree. Often you will count them on the trunk, but you can also count them around branches or even twigs. By counting annual rings in a pattern for several years, you can figure out how fast that tree grows each year.
2. Living Branches
The tree is responsive to its environment. Limbs can be affected by diseases, heavy winds, drought, or other environmental stresses. Limbs that are dead or dying can affect the overall health of the tree. This explains frequent tree trimming in Portland. If a limb dies, it will often break off when it falls to the ground, so you can count limbs as they fall away. After a couple of years, you will notice a pattern in how many new limbs grow each year and how quickly they grow.
3. Healthy Bark and Trunk
A tree’s health can be determined through its bark and trunk. The bark reacts to stresses that it may experience. If the bark has scales or cracks, it is likely to suffer from drought or wind damage. Count the number of grooves in the bark, then compare them to where you found healthy branches and twigs.
4. Full, No Bare Patches or Spots
Bare patches or spots on the tree are one sign of a disease. You can spot bare patches or spots on the tree using your bare hands (use rubber gloves to protect your hands from diseased sap), binoculars, a magnifying glass, or even a smartphone camera. If you spot any of these signs it should be reported immediately. Anytime you see any disease symptoms, it is important to report them to your local conservation office so they can intervene and try to prevent the spread of a serious infestation.
5. Healthy Leaf Characteristics
You can tell a lot about a tree by the way its leaves look. Leaves that are thick and healthy will be large and green, with no holes or scars. You can twist or pull the leaves gently to see if they come off easily; a healthy leaf will not fall off even when it is twisted or pulled. You should also see that the buds are green or brown, not black. Their presence on the tree must be monitored because they grow into new leaves and branches, which allows the tree to recover from damage.
6. Recognizing Disease Symptoms
Diseases are one of the biggest threats to tree health. Every year diseases affect millions of trees throughout the world, reducing their strength and causing them to die. Whether they are caused by insects, fungi, bacteria, or viruses, diseases attack every part of a tree and cause it to become weak. These problems can spread quickly if not handled correctly.
The best way to know if a tree is in good health or not is to observe it regularly. This method allows early detection of problems, which gives you more time to take action and prevent the spread of diseases. Help maintain good tree health by keeping an eye on our trees and recognizing the signs of trouble so they can be addressed quickly.