We get this question a lot. The short answer is between 3.25" and 3.75". Read on for more details.
We follow the guidelines put forth by Cornell University College of Agriculture on turf care. You can learn more about that by clicking here. Here are a few highlights:
In the Northeast, lawns are composed of cool-season grasses. There are several varieties of cool-season grasses, the most common are Kentucky Bluegrass, Tall and Fine Fescue, and Perennial Ryegrass. Unless you sought out a specific variety of grass, your lawn is almost certainly a combination of these varieties. Some of these varieties perform better in different conditions, so a common practice is to seed a new lawn with a mixture of different varieties. Parts of you lawn with lots of shade will allow some varieties to thrive, and parts that get full sun will allow other varieties to thrive.
Can you cut my lawn shorter?
Maybe. If we're already cutting your turf at 3.25", we won't cut it any shorter than that. The bottom line is that all cool season grasses are healthiest when cut between 3.25" and 3.75". Cutting it shorter is not only stressful on your turf, which makes it more vulnerable to pest and disease, it also lets more sunlight hit the surface of the ground, which promotes weed growth. When grass is tall enough to shade the ground, new weed seeds that sprout are starved of sunlight and die. We get this request most often when a client is receiving every-other week service. If you feel your lawn is too long, you may need to consider switching to weekly service.
Remember, for your turf to stay healthy, you should ideally be cutting no more than 1/3 of the hight of the grass off. So if your grass is 4" to 5" after a week of growth, cutting it down to 3.5" is ideal. If your grass is 6.5" after two weeks and you ask us to cut it down to 3.25", what you're asking us to do is stress out your turf.
You may be thinking to yourself "But what about my local golf course?" Putting greens and fairways are seeded with a specific variety of grass that can tolerate being cut very short. The most common of which is Penncross Bentgrass. While this variety can tolerate being cut short, it also requires much more maintenance. In order to stay green at this height, it is cut roughly every day depending on weather, and a very extensive fertilization program is in place. This is not practical for a typical residential lawn.
If you have any further questions about how we care for your lawn, just click on the "Contact" link at the top of the page.