By Dr. Bill Barrick, Executive Director
Like Kermit the Frog, one of my favorite colors is green, particularly in the winter months. We are fortunate to live in a climate with relatively mild winters, allowing us to enjoy the beauty of camellias and color provided by cold hardy annuals.
But we do receive enough cold temperatures for our lawns to become somewhat dull, or at least, not like the rich emerald color of spring and summer. In Mobile, the dominant grasses we use for lawns are warm season grasses, such as St. Augustine, Centipede, Bermuda or Zoysia. Overseeding lawns with cool season grasses, such as annual or perennial ryegrass, will keep our lawns vibrant green throughout the winter. Overseeding is most effective on narrow-leaved grasses, such as Bermuda, and really should not be done on St. Augustine lawns.
Each year in late September or early October, we overseed the Great Lawn with perennial ryegrass. Overseeding needs to be done at this time when nighttime temperatures are still warm enough to get good seed germination and cool enough not to encourage diseases.
It takes about a week to overseed the Great Lawn. The process begins with scalping the lawn by setting the mover blades to cut the grass much shorter than normal. This process produces a huge amount of clippings.
At this stage the lawn looks like a hay field. The clippings are vacuumed and taken to our compost area. Once the seed is distributed over the Great Lawn, we run the irrigation system almost daily to insure good germination. Germination typically takes about a week; within two to three weeks, the overseeded lawn is pretty well established.
In late March and early April, we apply an herbicide treatment that is effective on cool season grasses and broadleaved weeds. Although the rye grass would not survive our summer heat, applying the herbicide reduces the competition and allows the dormant Bermuda to regenerate. By late April, the lawn is back to its full grandeur, ready to serve as a wonderful backdrop for the late spring, summer and fall plantings.