Top & Bottom: Book Summary

Topping off or priming the bottoms of trees might seem counterintuitive, but these practices, referred to as "tops and bottoms" in arboriculture, are often used to promote better tree health and growth. This is a complex topic with several techniques and considerations, so let's delve into the details.

Before we dive into specific methods, understanding the "why" behind these practices is crucial. Trees, like other plants, have a complex internal communication system.major player in this is a hormone called auxin, produced in the tree's apex (top) and roots (bottom). manipulating these hormone production areas can impact overall tree growth and health.

Understanding Topping

Topping, the process of removing the top part of a tree, is a contentious practice. While some arborists advocate for it, others strongly advise against it. The main argument for topping is that it can encourage bushier growth, which is desirable in some cases. However, it's essential to understand the potential drawbacks.

When a tree is topped, it's effectively injured. The tree's natural response is to produce more hormones to try and save itself. This often results in rapid, weak growth that's more susceptible to disease and damage. Moreover, topping can also change the tree's natural shape, leading to an altered appearance and stress on the remaining structure.

Selective Topping

One popular topping technique is selective topping, or drop crotch reduction. This method involves removing only specific branches, usually to reduce the risk of storm damage or to pull a tree's canopy down for easier pruning. Unlike aggressive topping, selective topping can be beneficial and is generally accepted in the arboriculture community.

To perform selective topping, arborists typically look for weak, dead, or rubbing branches, as well as those that are too large or poorly attached. By removing these branches, they're not only improving the tree's health, but also maintaining its natural shape and structure.

Alternative to Topping

Rather than topping, many arborists advocate for proper pruning, which involves removing entire limbs, including their branches, back to their point of origin. This encourages the tree to heal properly and promotes better growth.

Proper pruning also helps maintain the tree's natural shape, reduces the risk of limb failure, and can make the tree safer and less prone to disease. It's a more involved process than topping, but the results are often more aesthetically pleasing and healthier for the tree.

Understanding Root Pruning and Girdling

Pruning and manipulating the roots (or "bottoms") of a tree is another controversial topic. While it's generally accepted that root pruning can help control a tree's size and shape, radical root cutting, or girdling, is widely discouraged.

Root pruning involves carefully cutting back specific roots to control the tree's size and counteract the effects of trees growing in confined spaces. However, girdling, which involves cutting all the way around the tree's root flare, can kill the tree by blocking the flow of hormones and nutrients.

Root Pruning Techniques

There are several techniques for root pruning. One common method involves deep rooting, where a long, vertical cut is made into the root system to encourage deeper, healthier growth. Another is trenching, where a trench is dug around the tree to sever feeder roots and limit its size.

Both these techniques can be beneficial when used correctly, but they require careful planning and execution. Over-pruning can stress the tree and leave it vulnerable to disease and damage. Moreover, improper root pruning can change the tree's water and nutrient uptake, altering its overall health and growth.

Trenching and Soil Management

Trenching isn't just about cutting roots; it's also a form of soil management. By removing soil from around the tree, you're reducing competition for water and nutrients and fostering a healthier root environment. However, it's crucial to refill the trench with clean, well-structured soil to prevent future problems.

After trenching, regular monitoring and maintenance are essential. This might include adding mulch to retain moisture and prevent erosion, or applying fertilizer to replace lost nutrients. The specific needs of the tree will vary, so it's important to work with a certified arborist who can provide personalized care.

Remember, every tree is unique, with its own specific needs and vulnerabilities. What works for one tree might not work for another. It's always best to consult with a professional before performing any significant tops and bottoms operations. After all, the goal is always to promote the health and longevity of your trees.