10 lawn mistakes everyone makes in the fall
Raking leaves is only step one.
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It’s fall, and the end of lawn-mowing season is finally in sight—but that doesn’t mean that you can slack off on lawn care. Avoid these 10 common mistakes to make sure your lawn stays healthy now, and looks lush and green next spring.
1. You stop watering
The weather may not be hot enough to turn your grass brown, but your lawn still needs water to grow and be healthy. Grasses need 1 to 1.5 inches of water per week throughout the growing season.
Grasses grow best when the water drips in slowly in a single long stream, allowing time for water to reach the deepest roots. Short bursts of watering just wet the surface, and most of the water evaporates before it reaches the roots, which doesn’t help your grass, but does help shallow-rooted weeds like crab grass.
Check if your lawn needs more water with the footprint test. Walk across your lawn, and look back. If you can still see your footprints in the grass, you need to water your lawn.
When you do water your lawn, water in the early morning so that the grass surface can dry off. Cool fall temperatures at night combined with moisture can promote lawn diseases.
If you use a sprinkler (like one of our top-rated smart sprinklers), you can measure how much water you’re putting out with the can test: Place six cat-food cans around the lawn, and run the sprinkler for 30 minutes. Measure how many inches of water are in each can, and find the average. Multiply that number by two to get the inches of water your sprinkler puts out per hour. Time your watering to get 1 inch of water into your lawn.
If you have a lawn irrigation system, remember that you need to drain your irrigation lines before frost.
2. You let leaves build up
In the autumn, your lawn can go from clear to leaf-covered overnight. Leaves may look pretty on your lawn for a day or two, but once they get wet, they’ll form a dense mat that’s hard to remove. Those matted leaves also trap water next to your grass and keep it from drying out—a perfect environment for fungal diseases. Keep your lawn from turning into a mushroom farm by raking your leaves regularly.
Hate raking? Consider using a mulching mower to compost your leaves in place. Leaves make excellent compost to nourish your lawn. Some mulching mowers can also bag shredded leaves if you don’t want to leave them on your lawn. Just remember that it’s illegal in many states to send yard waste into a landfill, so you’ll need to either spread the mulch or compost it somewhere on your property.
3. You ignore the bare spots
Farmers sow their crops in the spring, but the best time of the year for reseeding lawns is the fall. Fall planting gives grass a head-start on growing the next spring, helping the plants to establish deep, healthy roots before summer heat halts growth. Reseed your lawn in the early fall—early to mid September in northern areas. Consult your local agricultural extension for the best planting dates in your area.
When you’re planting grass, only use the recommended amount of grass seed the label recommends. Adding too much seed just makes your grass crowded, leading to spindly, weak blades. Keep watering your young grass until frost.
Check whether your spots are caused by shade, activity from pets or children, or problems like white grubs or patch diseases. For a lush lawn, in addition to reseeding, you may need to change your landscape, how your water and fertilize your lawn, or where you let your dog and kids play.
4. You stop mowing too soon
There’s a lot of debate about how high to mow your lawn in the fall. Some experts recommend cutting the grass shorter in the fall, to allow the soil to dry out between mowings, but others recommend keeping the grass the same height as in the summer to help the grass maintain long, healthy roots and shade out weed seeds.
That said, grass that’s left long over winter can encourage diseases and attract voles, pesky rodents that will devour grass blades and crown. Since they leave roots alone, voles seldom cause permanent damage to lawns, but they can make your yard look disheveled in early spring. Discourage them by keeping your grass to 3 inches for your final mow.
Whichever approach you choose, most grasses should be cut to 2.5 to 3.75 inches. To avoid stressing your grass, never cut more than one-third of the grass blade at a time.
5. You stop fertilizing
Your grass grows more slowly in the fall, but it’s still growing—and if you live in the North, your grass is putting a lot of its energy into growing roots, not blades. Grasses should be fertilized during their major growth seasons, and Northern cool-season grasses like fescue do most of their growing in the spring and fall.
Iowa State University recommends fertilizing northern lawns once in early fall to help grass recover from summer stress, and once in late fall to promote spring growth. Southern gardeners growing warm-season grasses like zoysia grass should skip the fall and fertilize in the late spring: Ask your local agricultural extension for the best timing for your area.
6. You skip the soil test
Before you drag out the fertilizer bags, get a soil test to figure out what your lawn needs. Hardware stores and garden centers sell home soil test kits that will tell you how much nitrogen, phosphorous, and potassium there is in your soil (listed as NPK on fertilizer bags). For a more thorough analysis of your soil, contact your local agricultural extension.
Lawn fertilizer generally comes in three types: fast-release, slow-release, and compost.
Fast-release fertilizer will make your grass grow fast, but it’s easy to apply it unevenly, making your lawn look patchy. Apply too much and damage your grass.
Slow-release or controlled-release fertilizer is easier to apply, and is less likely to “burn” your grass, but it’s more expensive, and takes longer to work. Organic fertilizer is a type of slow-release fertilizer with ingredients derived from plants and animals like bone meal, feather meal, and seaweed.
Compost adds both nutrients and organic matter to your soil for long-term soil health. Apply compost by cutting your grass to 1 inch and raking half an inch of compost over the grass as a top-dressing.
In some states, like New York, it’s illegal to apply fertilizers with phosphorous to lawns because stormwater runoff from lawns can pollute waterways. Check with your local agricultural extension to find out if there are restrictions of fertilizers in your area.
How much do you need? Follow the directions on the bag to the letter; you’ll need less than you think. Remember, applying more fertilizer than the package says will waste your money and damage your plants. Don’t apply powdered or granular fertilizer just before a rain—it will run off in the rainwater. If you’re using compost, plan on using three-fourths of a cubic yard per 1,000 square feet of lawn.
7. You put your lawnmower away as-is
Before you put your lawnmower in the shed for the season, you need to take a few minutes to prep it for winter storage. Otherwise, you’re just asking for rust and a wrecked engine.
Clean your lawnmower deck of any dried, stuck-on grass and debris. John Deere recommends using wooden shims to scrape off caked-on grass, then power washing or using a hose on your mower. Let it dry thoroughly before storing.
If you have a gas mower, water condensation mixed with ethanol in gas can clog and corrode your mower’s motor—and if you keep your mower inside your home, the fuel is a fire hazard. If you have just a little gas left after your last mow of the season, you can let the mower run for a few minutes to get rid of the fuel. You can also remove the fuel with a siphon hose and store it in a safe container. If your tank is full, add a fuel stabilizer to protect your mower through the winter.
If you have an electric mower, check your owner’s manual for instructions on temperature and charging requirements. Most electric mower batteries need to stay between 40°F and 80°F for longest life, and storing them in the charger for long periods can cause damage.
8. You aerate your lawn when you don’t have to
Lawn aeration means making a series of small holes in your lawn. If your lawn is compacted from heavy foot traffic, has more than a half-inch of thatch, or if your soil is heavy clay, aerating your lawn can help get more oxygen to your grass’s roots and the soil microorganisms that break down thatch. Lawn aeration can benefit any lawn, but it can be a lot of work, so if it doesn’t meet that criteria, it isn’t strictly necessary.
If you choose to aerate, experts recommend having holes 1 to 6 inches deep, about 2 to 6 inches apart, or 20 to 40 holes per square foot.
To make those holes, most homeowners rent a core aerator, heavy motor-powered machines that punch out wine-cork-sized clods of dirt as you push it along the ground. Near us, most places have aerators for rent for about $50 for four hours, which is enough time to take care of a small to medium-sized lawn (less than 10,000 sqft). Just to reiterate: these are heavy, unwieldy machines. They're simple enough when you know what you're doing, but they are potentially dangerous if you're not extra careful.
For smaller lawns, some gardeners opt for spike aerators (like this highly reviewed tool from Yard Butler), which are modified pitchforks you drive into the ground by hand. Aerate when the soil is moist, but not wet; two days after a thorough watering or heavy rain is ideal.
You can fertilize and reseed your lawn immediately after aeration. It’s a good idea to follow your aeration with a top-dressing compost to get more organic matter down into the soil to improve the soil’s structure. Any fertilizer you apply will be more likely to get absorbed into the soil instead of running off in the next rainstorm.
9. You give up on killing weeds
Sure, frost is going to kill them soon, but fall is the season when perennial broadleaf weeds, like dandelions, are sending sugars down to their roots to store for next spring. Fall is the best time of the year to get rid of them.
You can pull dandelions or use herbicide. If you spray, opt for spot-treating individual plants instead of broadcasting herbicides over a wide area. It’s easy to spray weed-killers too far, accidentally poisoning your lawn, plants, pets, and wildlife, including the bees that are pollinating your fall flowers.
Before you spray, think carefully about whether the plant you’re looking at is a weed. Many lawn experts recommend keeping the clover in your lawn. Clover adds nitrogen to the soil and also attract earthworms that keep your soil aerated and full of organic matter.
10. You don’t consider lawn alternatives
Many people maintain their lawns because they enjoy it, but if you’re tired of the unending routine of watering, mowing, fertilizing, and weeding your lawn, fall is a great time to think about alternatives. With a little planning, you can remake your landscape to need less maintenance and water. Consider groundcovers, mulch, or even turning your lawn into a beautiful meadow.