For hundreds of years, a certain breed of patient gardeners has mastered the skill of bonsai, carefully restricting and nurturing trees that would otherwise get to be 50 or 100 feet tall, so that they would fit on a desktop as an object of wonder. The viewer is filled with awe and astonishment at how someone could achieve such a feat. It is not without great skill and effort, as such a restricted environment is fraught with great peril for a tree.

Many of us have seen images of trees that have roots depicted as being just as large underground as the canopy of branches reaching overhead. I have since learned that the root system can be much more extensive than the volume of branches that are visible above ground, more than twice the width of their canopy.

So what happens when we constrain a tree in a space that is significantly smaller than the tree would normally need to reach maturity? It’s what you might expect: The tree dies.

Because of rules written into our county’s zoning codes, property developers must provide a certain amount of parking spaces for every building they erect, and a certain number of trees. As one would expect, the developers have an eye to minimize expenses and maximize profits, all while operating within the boundaries of the law.

As a result, many trees in Baltimore County must live out their short lives in areas that may be as little as 6×10 ft, or 180 cubic feet of soil, which limits its potential canopy spread to about 10 feet before the tree’s health starts to decline, eventually resulting in the tree being replaced by a new young tree (typically not before someone files a complaint).

Research indicates that trees require 1 to 2 cubic feet of soil volume for every square foot of canopy spread. A tree with access to 500 cubic feet of soil can achieve a canopy spread of over 20 feet. Washington, D.C.-based Casey Trees recommends soil volumes should range from a minimum of 400 cubic feet to over 1,000 cubic feet to maintain healthy urban trees that do not need replacing every seven to eight years. If it seems like a waste of money and resources to replace young dying trees before they reach maturity, you would be right.

On Nov. 7, the Baltimore County Planning Board will hold a hearing to discuss updating its Landscape Manual, which delineates regulations for the planting of urban trees, among other things. Of primary consideration is that our urban trees need adequate space to reach maturity, when they may then serve as habitat, provide shade and cool clean air, and enhance the beauty of the environment.

In the original writing of the Baltimore County Landscape Manual, adopted in 2000, the focus was creating consistency of style in landscaped areas. Changes now under consideration should prioritize survival and problem-solving in light of the ecological challenges ahead. What has become apparent over the last two decades is how critical it is to utilize native plants to support our ecosystems — to help capture stormwater in bio-retention basins (which filter toxins instead of allowing them to pollute the Chesapeake Bay), to support biodiversity in landscapes (thus preventing wholesale destruction from blights) and also to reduce the need for fertilizers, pesticides and herbicides. It is a lost opportunity if the updated Landscape Manual does not take steps to meet our challenges in a way that reduces spending and helps mitigate future difficulties.

If you need more convincing, besides the beauty of a mature tree, think of what a victory it is to find, in the heat at the height of summer, a bit of shade to park beneath. Wouldn’t it be nice if trees were allowed a bit of space to mature and provide shade? Wouldn’t it be marvelous if there was enough shade to go around? Trees will provide shade, coolness, beauty and sustenance to wildlife, if we just give them a chance.

Amanda Wray is president of Wild Ones Greater Baltimore and a member of the Maryland Native Plant Society and Green Towson Alliance.