The fall is unofficially here and along with putting away the white in the wardrobe until spring, many are taking this time to aerate and seed their lawns. But there is another part of the home landscape that should not be overlooked at this time. While you’re looking down at the ground and giving your lawn some ‘TLC,’ don’t forget to look up and give your trees the proper care they need as well.
Growing grass under a tree can be tricky business. Often, the ground below a large tree may be barren and does not easily support a lush, living, green carpet, as the shady conditions allow little sunlight to reach the ground. Also, when grass grows beneath a tree, the roots of the tree and the roots of the grass compete with one another for water and nutrient resources. Add to that the current dry spell and drought conditions occurring almost statewide, and you will probably end up with plants that are stressed because they are unable to get what they need to thrive.
These trees are in deep trouble! Mulching that is piled too high on the trunk can cause disease issues, decay, or allow the formation of abnormal roots. Image: Gary Watson, Morton Arboretum, Bugwood.org.
One of the best things you can do to encourage the health of all plants in your landscape while maintaining aesthetics is to mulch the area beneath a tree. Not only does this look natural, but it retains soil moisture for optimal tree health, reduces the risk of soil compacting or tree wounding by lawn equipment, and slowly releases nutrients as the mulch decomposes. It also keeps grass from growing in that tricky below-canopy area. Mulch, shredded bark or pine needles can be applied around the base of a tree at 2 to 3 inches deep. A layer that is too thick may starve the tree of water and nutrients. Also, be sure not to set a peak of mulch around the trunk of the tree, as this will encourage the growth of disease pathogens, bark and stem decay and may cause abnormal root growth. With mulch, grass and trees can grow happily without sacrificing the beauty of your landscape! It’s a match made in heaven.
But some really like the look of grass under trees or may have other reasons for encouraging its growth. While it may be challenging, there are a few things you can do to help provide the resources that lawn and tree both need. Obviously, as trees grow, their canopies get larger and shade more area over time. Selective pruning by an arborist can allow more penetration of sunlight to the grass below. It would also be wise to select a shade-tolerant grass and not mow the grass as short as the rest of the lawn. A longer blade means more sunlight-gathering surface.
With some simple planning, you can have a lawn and tree that live happily… almost at happily as you with the summer heat behind us!