How Lawns Kill Trees
A lawn mower physically prevents any tree seedling from growing by cutting it short and removing its leaves, which eventually kills the seedling. But there are many more ways that lawns and trees are incompatible and therefore drive our need to create a protective canopy for our homes and streets. When we think of a forest, we don’t see grasses in that picture.
Grasses are very good at dealing with direct-sun conditions such as prairie and savannah landscapes that generally also have extended dry spells during which the grass goes into dormancy.
A forest is able to absorb nearly all of the sunlight high in its canopy, which also keeps the ground below cool. A consequence, however, is that only particular plants can live in the dappled light level and grass is not designed for such a dim circumstance.
When we prioritize a lawn’s health in our landscape designs, we deny the requirements for healthy tree establishment.
This is one of the primary reasons why trees have such a difficult time surviving in city conditions, particularly when we place them singly in a lawn or street boulevard.
Generally, the health of the lawn is our aesthetic priority and thus we provide sufficient irrigation and nutrients to keep it green. Grass root systems are very dense and water is quickly taken up and absorbed by the grass – generally before it reaches a tree’s root system.
Water is vital for trees during hot and dry summer seasons when they are focusing on their annual extension growth. Once their roots get dry, all new growth stops for the season.
Eventually, year after year of drought will dwarf the tree and defeat the original intent of planting them, which is to have the pleasure of long-lived, large and healthy trees – with all the many benefits their tree canopies bring to our lives in the city.
Planting trees in grassed areas today normally involves creating a mulched bed around the trunk as we recognize the importance to not have lawns near the base of trees in order to prevent accidental mechanical damage to the base of the tree (mowers, trimmers, etc.). Additionally, the mulch cools the roots and allows water to enter the soil without competition from the grass. Extending this knowledge of the benefits to trees, we can plant additional shrubs and other trees in close proximity within a shared mulch base, and re-create a small woodland area which will enable the trees’ root systems to develop fully. Thus it will be able to tolerate dry conditions more easily. Lawns will become a smaller part of our landscape design and, instead, we will create areas where both trees and shrubs grow together in a low-maintenance landscape. In this way, it will be natural to have evolving, healthy woodlands outside our homes.
Trees will thank us. 🏡