Having a well maintained lawn not only gives you an accomplishment to be proud of, it also adds beauty and aesthetic value to your home.
Determining the correct height at which to cut your lawn varies with a few conditions, the most important being your climate and location. Before looking at climate and location however you need to be especially careful in lawn cutting when you have recently seeded your lawn.
Cutting your lawn too soon after seeding will not only remove many of the seeds yet to begin growth but it will also kill the newly growing grass that has not developed enough to withstand a mowing. After seeding you want to wait at least 3-4 weeks before mowing at all to give your lawn a chance to develop, root, and become healthy. This may leave your lawn higher then usual for a while but it is a required step in keeping your new lawn alive.
One reason for not cutting your lawn too short is due to ‘burning’. If you live in a warm climate where sunny days mean a lot of heat, a short lawn will more easily ‘fry’ under the beating sun. Longer blades protect shorter (and thus immature) blades from the damage of the sun. Also longer grass dissipates some of the suns rays, allowing moisture and nutrients to remain in the soil a little bit longer then if exposed to the full glare of the sun.
A good height is a around 2 inches to get the balance between looking well maintained and protecting from sun damage in warm climates. Of course in cooler climates or areas that receive less sun, you can trim your lawn a bit shorter. At the same time you do not want to keep your lawn height too high as this will not only look messy but will encourage many creature visitors to move into your lush jungle like lawn.
Also more moisture may be retained inviting bugs such as mosquitoes which carry West Nile virus and other bugs that will chow down on your lawn. Plus, just like cutting too short will expose new blades to more sun then they can handle, leaving the lawn too long can block out the sunlight needed for growth of new blades and new seeds. Of course the only time to let your lawn grow above 2-2.5 inches is in the early seeding period or if you have recently laid down new sod.