A preventive pruning program should be designed to create structurally sound trunk and branch architecture that will sustain a tree for a long time and keep it healthy especially during northern California’s coming rainy season. At Image Tree Service, Inc. in Windsor, CA, one of our main goals with mature trees is to develop and maintain a sound structure to minimize hazards such as branch failure, something that is prevalent during January through April when the rain is at its peak.
When properly executed, a variety of benefits are derived from pruning, weight reduction and clearing the crown. Benefits include reduced risk of branch and stem breakage, better clearance for vehicles and pedestrians, improved health and appearance, and enhanced view. When improperly performed, pruning can harm a tree’s health, stability, and appearance. Several consequences occur when pruning is not performed at all. These consequences include development of low limbs; weak, co-dominant stems and accumulation of dead branches. Formation of co-dominant stems and bark defects can lead to increased risk of breakage.
Jeff Kowell, the owner of Image Tree Service knows from experience that the rainy season is here and that’s why weight reduction for your trees is a wise and timely thing to do.
“The rain can really damage your trees, because the tree’s roots can become over-saturated with water and then the tree can become top heavy with rain,” he explained. “So, it has a double effect—the tree is weak from the bottom and the branches are holding water from the top. If you don’t deal with it and then the heavy rains come, your tree can topple and completely pull itself out of the ground.”
One of the most common defects in planted trees is formation of large, low limbs. Branches of this nature could overextend and break, or they may droop under their own weight and have to be removed later, leaving a large pruning wound. Removal of large branches and those more than about half the trunk diameter is more likely to initiate decay than removal of smaller branches. Measures should be taken to avoid the occurrence of this defect. With mature trees it is important to minimize hazards such as branch failure. Failures not only hurt the tree, but can also cause damage to people and property.
Wind can also be a hazard for any tree, according to Kowell. “Heavy winds can cause havoc to trees, because if the branches don’t allow the wind to pass through, a sail effect can occur, which can lead to branch failure and eventually the entire tree can split. We’ve seen falling trees damage homes and commercial buildings. Call us today and we’ll come down and look at your trees at no charge. Future problems can easily be alleviated if you act in time and we can surmise the situation rather quickly after inspecting your trees.”
Live branch removal is less desirable on mature trees, but it is sometimes necessary, for instance to remove a cracked live branch above a house. A horizontal crack greatly affects the structural integrity of this branch. As such, it is a good candidate for reduction and/or thinning. The goal is to alleviate forces at the base of the branch. This is accomplished by reducing weight at the end of the branch so that the risk of breaking is minimized. Cleaning the crown by removing dead, diseased, or broken branches is a highly recommended practice on mature trees. When planning a pruning program, it is essential to first evaluate the tree and the customer’s needs. This will assist the tree’s owner in determining which objectives should be accomplished with pruning.
“Root damage often occurs when building contractors and grading contractors damage a tree’s roots by excavating during construction or by parking vehicles too close to the trees and a whole range of other issues,” he said. “To avoid this, we often consult these contractors on how to prevent this from happening. Using an air-spade, we can expose the tree’s roots safely and alleviate problems such as tree stress or root decay. If a contractor wants to install pipes in the vicinity of the tree’s root system that can be achieved with the air-spade and the roots can be saved, in most cases. When the fine, very small roots at the top of the soil get damaged it means that they can’t deliver nutrients to the larger roots down below, so the tree’s root system fails and the tree (like the one here) will eventually die. These fine roots near the surface are the absorbing roots, so by using the air spade, we can protect the main life source for the tree.”
According to www.treehealth.com radial trenching is a treatment performed to trees growing in compacted or poor soils. It is a way to get oxygen to roots, replace soil, and to alleviate compaction.
Radial trenching is performed using an air-spade to remove soil radially from the trunk out to the roots. Narrow trenches are created using high air pressure in a radial pattern throughout the root zone. These trenches appear similar to the spokes of a wagon wheel. Trenches will be 8-12 inches deep 3-4 inches wide. Using high pressure air tools causes minimal root damage.
Narrow trenches are dug in a spoke pattern around the tree, then backfilled with topsoil or compost. Root growth in the trenches will exceed root growth in the surrounding soil. A 2- to 4-inch layer of wood chips may also be added over the top of the backfilled trenches.
The narrow trenches can be backfilled with the topsoil or compost. Root growth will be greater in the trenched area than in the surrounding soil. This can give the tree the added boost it needs to adapt to the compacted soil or new grade.
Rain and wind can create a double whammy for trees and a totally healthy tree can topple in a worst case scenario. “Other issues arise after heavy rains because the soil gets saturated the water can’t drain off,” Kowell explained. “The ground around the base of the tree loses its integrity and if the tree hasn’t been pruned properly the wind will cause a sail effect and then the tree is susceptible for toppling and then you’re in a lot of trouble.”
In upcoming blog articles, we’ll discuss tree protection programs, strategic watering schedules and how to prepare a tree properly during construction.