Live Oaks(Quercus virginiana) have a genetic characteristic of growing wide, not very tall. The Texas Champion Live Oak has a spread of 150′ and a height of 44′ to give a general view of what a mature Live Oak looks like. Most Live Oaks, if not all, in the Dallas area are of this type.
Homeowners generally space them out to be one on each side of the front entry. Most city codes require 2 trees at 4″ DBH (Diameter at Breast Height) in every lot. If planted in the middle of the yard on each side of the entrance of a standard 100′ lot, the trees growing with just the irrigation and no other practices such as fertilization and pruning would grow into each other in less than 20 years. If they were appropriately pruned in accordance with pruning/growth cycles and properly fertilized, it would happen much sooner.
Actual property example: There are 19 live oaks in the front yard of this property spaced less than 40 feet apart, which means that in less than 15 years they are into each other.
When planted, most are installed in a landscape accompanied by grass, generally Bermuda grass. Bermuda grass is a creeper grass that requires sunlight all day long, irrigating and fertilizing with a high nitrogen fertilizer. When it does not receive these requirements it stresses and thins, making it easily susceptible to secondary infections. As the tree, the dominant organism in the landscape grows and responds to pruning, it dictates the environment underneath it, absorbing moisture/nutrients and sunlight.
Trees are pruned for health and structural benefits, thinning in addition to this to create an environment conducive for grass growth and or maintenance is counterproductive and harms tree health. Thinning the tree to provide enough sunlight for grass throughout the day is hopeful at best and harmful at least. As Arborists, we understand trees will respond in growth when pruned, it is our responsibility to train that growth in such a way that encourages it in a positive direction and compliments its genetics.
Trees live longer and they increase in size and value. They work up a relationship for the present and next generation of homeowner.