I enjoy taking care of my lawn. However, through my involvement with the Anne Arundel County Watershed Stewards Academy, I've learned that some common lawn care practices can have a negative impact on our local watersheds. Since it's early spring, and many of us are focusing on our lawns, now is a good time to examine several options for environmentally responsible lawn care.
Researchers at our regional state universities have now determined that an early spring application of fertilizer is not beneficial to the health of our “cool season” lawns.
Most of us in this area have lawns composed of either fescue or bluegrass which are considered cool season grasses because the turf grows best in the spring and fall. In the past, an early spring application of fertilizer on our lawns was encouraged in order to quickly turn the lawn green.
Unfortunately, this quick green-up prevents the grass from developing deep roots which help the lawn endure the summer heat. Turf scientists are now recommending that we should skip the spring feeding and only fertilize our lawns twice in the fall, once in late September and again in mid- to late October.
An additional benefit to following this new recommendation is a reduction in the amount of nitrogen and phosphorus in the storm water runoff from our yards. High nitrogen levels in our creeks and rivers feed excessive algae growth which, when the algae die, robs the water of the oxygen needed to sustain fish, oysters, crabs, and underwater vegetation.
Treating our lawns for weeds presents another set of challenges for our watersheds. Pre-emergent herbicides are great at helping prevent nasty crabgrass infestations, but the chemicals are not exactly friendly to the health of our streams and creeks. Corn gluten, applied as a weed preventer, has received a lot of attention in recent years, but it is expensive to use and requires three years to become truly effective. Removing weeds by hand or learning to tolerate a few weeds in our lawns is definitely a more watershed friendly means of dealing with weeds.
Once the mowing season begins there is another important practice we can use to help our lawns remain healthy and that is to mow the grass at the proper height. The recommended mowing height for lawns in this area is three to 3 and a half inches tall which is generally taller than we are accustomed to doing.
Cutting lawns higher helps shade the soil and reduce soil temperature which helps to slow weed growth and, reduce the need for frequent watering. Mowing our lawns regularly at these heights also makes it easier to let the clippings fall back in to the grass and recycle as mulch.
Improving the health of our creeks and rivers is a big job, but with each of us taking small steps like feeding our lawns only in the fall, living with a few weeds in the lawn, and mowing our grass at the proper height we can begin to help restore the health of our local watersheds.
For additional information on lawn care view the Chesapeake Bay Foundation lawn guide at: www.cbf.org/Document.Doc?id=35 or the Maryland Cooperative Extension Home and Garden Information Center at: www.hgic.umd.edu and select Lawns and the Chesapeake Bay, FS 702.