This is a busy time of year. We are harvesting tomatoes, zucchini and squash. Herbs and fruits are abundant. And while the hot weather has been good for most plants, many homeowners have seen their lawns brown this year. And they are concerned.
Usually the browning is nothing to worry about. It is just an indication that the lawn, stressed by lack of water and summer heat, has gone dormant. When that is the case, the grass revives with the increased moisture and cooler weather that naturally occurs in September.
However, this year the weather was so hot and so dry that many lawns have gone from dormant to dead and will not revive when temperatures cool.
How do you know which is the case?
“You need to get down on your hands and knees and look,” said Sue Beebe, assistant director of the Saratoga County office of Cornell Cooperative Extension at a meeting of the county’s master gardeners.
What you are looking for is a hint of green at the crown. Even the slightest touch of green means the crown is alive. To bring it back, water. Lawns need about an inch of water per week. The easiest way to determine if the lawn has gotten enough water either by rain or an irrigation system is to set an empty tuna can in the area and check it weekly. If the water depth in the can is an inch, you don’t need to water that week.
Promoting healthy lawns
Lawns that have the best chance of surviving stressful times are those that start the season with good health and vigor. That should be our goal.
There are tried and true methods for accomplishing this, and the next few weeks are an ideal time to begin.
Start with a soil test, so you know exactly what your soil needs. Your lawn may not need to be fertilized. If it does, from now to mid-September is the best time to apply fertilizer. And if weeds are a problem, September is prime time to apply a broadleaf herbicide.
But watch the weather. You don’t want to apply fertilizer on a hot day. If the forecast is for temperatures above 80 degrees, wait for a cooler day.
After spreading the fertilizer, water your lawn to ensure that the fertilizer penetrates the soil. Although they cost more, it is wise to look for a fertilizer with a high percentage of slow-release nitrogen. Most synthetic fertilizers have at least 40 percent slow-release nitrogen, but some have 70 percent.
Slow-release means that the nutrients will become available to the grass over a period of time rather than all at once. How fast depends on soil moisture, temperature and microbial activity. A slow steady release of nutrients has benefits to the plants and potentially to the environment.
Here’s why. The percentage of nitrogen that is not slow-release is water-soluble, meaning it dissolves rapidly and is quickly available to the plants. However, if you are on sandy soils, water-soluble fertilizers can pass through the soil too quickly. For readers who approach lawn care organically, the nutrients in organic fertilizers are slow-release.
Some lawn owners have a higher tolerance for weeds than others. For some people, if the area behind their home is green, even if it includes weeds and clover, they are content. I saw a lawn of thyme in the Adirondacks that was gorgeous. But I recognize that some homeowners need a lush, green pristine lawn.
There are cultural practices that help keep weeds away without chemicals. I will get to those. However, if you have more weeds in your lawn than you can tolerate, early to mid-September is the most effective time of year to apply a broadleaf weed killer. This is when the herbicide can kill the entire weed, roots and all.
Certain weeds are harder to eradicate than others. Oxalis, ground ivy, plantain and nut sedges, for example, require a liquid herbicide applied twice. For these tougher weeds, Beebe recommended not mowing two days before applying an herbicide and for three days after. Apply the herbicide once, wait two weeks and reapply using the same guidelines concerning mowing.
There are some other tips to follow when applying an herbicide: Don’t apply when rain is forecast within 24 hours of application. Don’t mow or water for at least 24 hours following application. And finally, granular herbicides are most effective if applied to grass that is moist, as the granules will stick to the wet weeds.
Keeping lawns healthy requires good maintenance practices. Here are the basics:
Keep the mower blades sharp and set the mower to cut at 3 inches. Longer grass can out-compete weeds and is less vulnerable to drought and insect damage. Cornell University studies show that longer grass has a better root system than turf cut short. And having strong roots is key to surviving stressful periods.
The exception to this rule will be the last mow of the season, which is generally in November. Cornell University’s website recommends the last mow be about 20 to 30 percent shorter to discourage problems such as matting and snow mold.
If areas of the lawn are thin, fall is considered the ideal time to reseed. If you have applied a weed killer however, you will need to wait until spring to seed. Also, avoid seeding during 90 degree weather. Wait until the temperatures cool to sow seed.
As you shop for grass seed, remember that you get what you pay for. Good grass seed will be a mix of different grasses such as rye, fescue and Kentucky blue grass. There are mixes available at local garden centers that were created for the New York market. There are also mixes created for high-traffic areas and shaded spots. Some grasses, such as fescues, can handle drought better than others. Think about what your needs are.
Finally, read the label; you want to buy seed that is no older than nine months. Seed that is older will have a lower germination rate. Don’t waste your money.
Natalie Walsh is a horticulturist, speaker and garden consultant. She can be reached at [email protected]
More from The Daily Gazette:
Categories: Life and Arts