An overly dense tree crown can be a major hazard. Not only does overcrowding in the crown compromise the health of the tree, but it also can increase the chances of branch loss and blowdown due to excess weight.
1. Friction Wounds
Friction is a real issue when the crown of a tree is crowded. Branches will cross and rub together, which leads to the bark flaking off of the branches. The missing bark increases the chances of branch breakage. Wounds from the missing bark can also lead to diseases invading through the bark wounds. Trimming the trees to remove the rubbing branches solves the issue and prevents damages.
2. Mildew Issues
Over-crowding in the crown reduces air circulation and increases humidity. This is a recipe for mildew and mold issues, which will coat the foliage and lead to leaf and branch death. Mildew isn't typically fatal, but it can weaken the tree and make it more susceptible to other health problems. Trimming out some of the branches allows airflow through the branches so that mildew is less likely to be a problem.
3. Sparse Foliage
Dense growth prevents sunlight from penetrating deeply into the crown. This leads to weak leaf growth. What leaves do grow in may be yellowed and stunted due to the lack of light, and they will often drop off prematurely. Not only is sparse foliage unattractive, but it also means that there is not sufficient foliage to support the excess branches in the crown.
4. Branch Loss
The above issues with disease and sparse foliage, along with damage from friction, all increases the chances of branch loss. Breakage is a common cause, but a tree will also sometimes spontaneously drop a branch. A broken branch can damage neighboring branches when it breaks, or it can damage things below such as a home's roof or a parked car.
5. Tree Cracks
Excess weight in the crown puts stress on other parts of the tree. If there are any forks in the trunk, for example, the weight can lead to a split trunk and the death of the tree. Cracks can also form around the base of the heavier branches, which can lead to major damage if they break. Thinning out the crown removes the excess weight and prevents cracks and splits.
Contact a tree trimming service for proper pruning if you notice these issues with a crowded crown, like Live On Tree Service.