If you have a tree with multiple trunks connecting at or near the base, you should have it evaluated for structural integrity. These trees are most at risk for structural damage.
In these areas where trunks or major limbs grow together at a narrow angle (or a tight “V”), the pressure they exert on each other increases each year as each trunk expands in size with its newest layer of wood (these are the rings you see in trees cut down).
In addition to the increase in pressure, the canopies up top continue to grow and add weight. With increasing mass, they also catch more of the wind and move around more in heavy storms. This all adds up to a high potential over the long term for a tree like this to split apart and collapse.
In conjunction with reduction pruning (to reduce canopy weight and mass), we can install support cabling between two or more trunks so that they help support each other and are less likely to split apart.
Old cabling systems use metal cables and hardware drilled into the tree. These can cause wood decay and as a result may weaken or fall out over time, as well as diminish the circulatory health of the tree.
The cabling we use is non-invasive and there are no metal parts. It is a dynamic, shock-absorbing polypropylene-based braided cable that is installed by wrapping around the trunk or limb, and it can support literally tons of weight. It is also flexible, expanding as the tree grows, so it can remain effective and in-place for many years.
Full disclosure – lightning protection systems can be expensive. They are primarily copper and are typically installed in very tall trees, requiring a lot of cable. They are, however, effective at re-directing the charge of a lightning strike and thus perhaps saving your tree.
Trees most at risk for a lightning strike are those that stand above most others in their surroundings. Strikes are surprisingly common – we see evidence of them in about 10% of the landscapes we visit. Their strength and intensity can vary from light (“just a flesh wound”) to heavy (total destruction) and anywhere in between. Just as in the case of people, a lightning strike may or may not destroy a tree.
If you have a beautiful, healthy “landmark” tree in your landscape, or one that forms the very foundation of your landscape, a lightning protection system may be a good investment.