At the risk of making a broad generalization, most of us cut our lawns too short and too often, particularly during the summer months. Short lawns often fall prey to weeds and diseases. In fact, the United States Department of Agriculture purposely cuts its test lawn plots short to encourage diseases for their experiments.
Why do we feel the need to cut our lawns so short? Are we searching for a bit of order and uniformity in our crazy, mixed-up world? Do we need to make our turf look like Augusta National (home of the Masters golf tournament) or Fenway Park? Whatever the motivation, lawn cutting sometimes approaches obsession in North America. Obsessions usually aren’t very healthy.
When an individual grass blade is cut a number of things happen. All growth temporarily stops, carbohydrate production and storage is reduced, water is lost from the cut end and water uptake drops off.
As long as the lawn is healthy and maintained properly grass can quickly bounce back from this traumatic experience. Under ideal conditions mowing helps to increase the number of individual grass plants, making for a tighter, more weed-resistant turf.
Unfortunately there aren’t many lawns grown under ideal conditions, Augusta and Fenway notwithstanding. If you combine repeated mowings with poor weather, drought, compacted soils, lack of water and nutrients and whatever else happens to your lawn, chances are the lawn’s health will decline. There will be fewer grass plants and more weeds.
Most of the lawn grass species in our part of the world are known as “cool weather grasses.” Such grasses; fescues, ryegrasses and Kentucky bluegrass, respond better to higher mowing heights, particularly during the heat of summer. It makes perfect sense because higher cutting heights leave more grass to shade the roots and reduce moisture loss.
You will notice that when the temperatures are high for days at a time the lawn grows more slowly. This is because these types of turfgrasses tend to go semi-dormant in summer, growing quicker in the spring and fall when temperatures are cooler. This means, thankfully, that you should need to cut less often, leaving more time for other summer activities.
So to sum up, raise the cutting height on your mower this summer. Don’t water it every day or every second day for a short period of time. Let it approach dryness (when it looks to be turning grey or when you can see your footprints after you’ve walked across it) and then water for a longer period of time. Fertilize if needed with a good quality slow-release lawn fertilizer.
If a few weeds should poke their heads through the thick and healthy turf you’ve nurtured don’t sweat it. Brown patches in the lawn are completely normal at this time of the year as the turf naturally goes dormant. Embrace them and watch them disappear when the cooler weather arrives in fall.