Here’s a good article on lawncare by Joseph Truini for Popular Mechanics.
It isn’t easy cultivating a perfect lawn, but avoiding these common mistakes is a good place to start.
Growing a lush, green lawn is well within the capabilities of any homeowner, as long as you follow a few simple rules. Unfortunately many lawns fail, not because of neglect, but because of some bad practices and misconceptions.
So, to help you have the greenest, healthiest lawn in the neighborhood, this compiled list helps you avoid the biggest pitfalls standing between you and a great lawn.
Mistake #1: Cutting the Lawn Too Short
As a general rule, grass should be cut no shorter than about 3 inches long. Trimming it too short removes much of the energy-producing top growth and puts unnecessary stress on the plant, making it more susceptible to insects and disease.
Adjust your lawnmower’s cutting height accordingly, but never trim off more than one-third of the grass leaves. Another important benefit of not cutting the grass too short is that thicker lawns do a better job of crowding out weeds.
Mistake#2: Mowing With Dull Blades
Regardless of whether you use a walk-behind or riding mower, it’s important to use sharp blades. Dull blades rip through the grass, leaving jagged ends that easily turn brown and make the grass more susceptible to disease.
It’s recommended that you sharpen lawnmower blades every spring and again about halfway through the mowing season. However, if you regularly hit rocks or scalp the ground, you’ll need to sharpen the blades more often.
Mistake #3: Not Testing the Soil
In order for grass to germinate and grow strong, the soil must have the right pH, which is the measure of acidity and alkalinity. The pH scale ranges from zero to 14, with 7.0 being neutral. Grass grows best in soil that has a pH between 6.0 and 7.5. To test the pH of your soil, buy a DIY soil-test kit for about $15 and follow the manufacturers directions. More comprehensive testing is available at your County Cooperative Extension office.
In most cases, it’s a simple matter of mixing a little soil and water in the kit’s plastic vial and then waiting for it to change color. The color-coded chart alongside the vial will reveal the acidity or alkalinity of the soil. If your soil is too acidic—below 6.0—you can add pulverized lime to raise the pH. If the soil is mildly alkaline—7.5 to 8.0—you can balance the pH by mixing peat moss into the soil. If the soil is very alkaline—over 8.0—lower the pH by adding sulfur.
Be aware that soil conditions change, so it’s important to repeat the test at least once every spring.
Mistake #4: Bagging the Clippings
As you mow, don’t collect the grass clippings. Instead, leave them on the lawn to decompose and they’ll provide much-needed moisture and nutrients. However, if the clippings clump together, be sure to rake them out. Otherwise they’ll form a thick mat and suffocate the lawn.
Mistake #5: Not Dethatching
To help grass absorb sunlight, nutrients and water, it’s important to dethatch the lawn at least once a year, preferably in the spring. Dethatching is the act of removing thatch, which is a layer of dead organic lawn matter, such as grass clippings and shredded leaves that forms on top of the soil. If the layer of thatch is ½ inch thick or thicker, in can starve the lawn.
For small lawns, you can use a thatching rake to remove the thatch, but in most cases it’s quicker and easier to rent a de-thatching machine. Simply run the machine back and forth across the lawn and its spinning tines will pull out the thatch. Then, rake up and dispose of the thatch.
Mistake #6: Not Aerating
Aeration is one of the most important steps to maintaining healthy lawns. Unfortunately most homeowners never aerate their lawn.
Aeration involves poking holes into the soil, so the lawn can more easily absorb water, fertilizer and amendments, such as peat moss. If you’ve got a small lawn, you can use a manual aerator, which is a spiked tool that you stomp into the ground to create a series of holes.
Otherwise, rent a power aerator, which is a walk-behind gas-powered machine that can punch thousands of holes in a matter of minutes. Just be careful you don’t damage any buried irrigation lines or cables.
Mistake #7: Improper Fertilizing
While most homeowners know it’s important to fertilizer a lawn, few do it correctly. Applying the wrong fertilizer or applying too much fertilizer can do more harm than good. And the correct fertilizer can be ineffective if applied too sparingly or at the wrong time of year.
Now, with that said, it’s difficult to give specific recommendations for fertilizing because so much depends upon the type of grass and region of the country, so it’s best to check with a local landscaper for specific recommendations. However, here’s an annual maintenance schedule that’s appropriate for most parts of the country.
March-April: If crabgrass is present, use a crabgrass preventative agent combined with a slow-release lawn fertilizer. However, don’t apply it until the grass is green and has been mowed a couple of times.
May-June: Apply a slow-release lawn fertilizer, if you didn’t do so in the spring. Treat dandelions and other broad leaf weeds with a dual-function “weed and feed” product.
July-August: Inspect lawn for insect pests. If necessary, apply a grub-control agent.
September-October: Apply a fall fertilizer to strengthen the lawn and repair summer damage. Treat bare spots with an all-in-one lawn repair mix that contains grass seed, mulch, and a quick-start fertilizer. And if you’re only going to fertilize your lawn once a year, do it in the fall. Grass leaves grow much more slowly as the weather cools, but the grass roots and rhizomes continue to grow strong. (Rhizomes are the horizontal plant stems that lie just beneath the soil’s surface; they produce the blades of grass above and the roots below.)
Mistake #8: Over Watering
Water, of course, is vital to growing and maintaining a healthy lawn, but over watering can be just as destructive as watering too little. If you water too frequently, the grass will fail to develop deep roots because there’s no need for it to reach deep down into the soil to find moisture. Watering correctly allows the grass to grow deep roots, creating a lawn that’s much stronger, healthier and better equipped to survive drought conditions.
As a general rule, most lawns require about an inch of water per week, but that varies widely based on weather, soil conditions, and grass species. For more specific information, contact a local nursery or landscaper.
Mistake #9: Not Raking Up Leaves
No one enjoys raking, but it’s important to remove leaves from the lawn shortly after they’ve fallen from the trees. If you wait until all the leaves have fallen or even worse, fail to remove them at all, the leaves will stick together and form an impenetrable mat, which can kill the grass and breed fungal diseases.