Have you ever seen a grassy area under the dense canopy of a forest? How about trees growing in an open meadow? Trees and grassy areas do not mix together in nature, yet we always try to incorporate them in the landscape.
Grass is a rapid growing, shallow-rooted, aggressive plant. Grasses thrive in full sun with moist soil. When grasses don’t receive enough sunlight they grow sparsely, allowing room for weeds to grow. If grass doesn’t receive enough water, it will be stunted and not grow as vigorously as possible, allowing for weed growth.
Trees grow in open areas where rain comes in phases. The soil dries out keeping smaller, less drought tolerant plants from competing for moisture.
Tree roots grow in the top three feet of soil, with the absorption roots living in the top 12 inches of soil. The absorption roots are responsible for the majority of nutrient and water uptake. Grass roots grow in the top six inches of soil and can reach depths up to 18 inches. Grass roots absorb water and nutrients quicker than tree roots because of their large number and being closer to the soil surface.
To have trees grow well in lawn environments, certain considerations need to be met. The further away the grass is from the tree, the happier the tree will be. By installing a tree ring, a divider from the tree and the lawn, you can help the tree in multiple ways. First, the tree roots will not be competing with the grass for water uptake. Secondly, the tree will not be subjected to injury from lawn mowers and string trimmers. The third benefit of a tree ring is that maintenance costs are lower because you do not need to edge around the trees and mow so close.
Broad-leaf herbicides are used in lawns to kill clover and dandelions. The negative aspect of this is that trees are also broad-leaf plants. Only spot treatment should be used in lawns with trees to apply the herbicide versus a broad coverage type application.
Lawns are irrigated by overhead sprinklers and typically receive about one inch of water per week. That is a satisfactory amount of water for grass, but does not meet the needs of a tree. One inch of water does not move that deep into the soil. To help satisfy a trees water requirement, you can turn a garden hose on a low flow at the base of the tree and let the hose run for a couple of hours to help water the tree roots deep in the soil.
While trees and grass do not mix in nature, by following these guidelines your trees and your lawn will co-exist much better.
