Keep off the grass and other lawn-care fundamentals
BY PAUL HETZLER (COOPERATIVE EXTENSON EDUCATOR) , IN VAL-DES-MONTS, QC
May 30, 2020 —
I’ve been wary of lawns since about 1970 when I saw a public-service TV ad which featured a leafy green bundle dropping into an eerily vacant playground. A baritone, God-like voice issued a dire warning, something like: “Grass. We think it’s bad for kids. Stay away from it.” My five-year-old mind rejected Mom’s account that some grass was bad but ours was OK, because she wouldn’t give any details about the bad stuff. It was a few days before I ventured onto the lawn again.
These days, “bread” is no longer money, “mint” is just a flavor, and in much of North America, “grass,” the kind one smokes, is now legal. Jargon may change, but things like paying taxes and mowing lawns do not.
Your lawn will probably not look like this, nor should it. Photo: paulbr75
It's not a golf course
At this time of year, a bewildering array of lawn-care products appear at garden centers. It’s easy to spend a lot of dough – I mean money – on fertilizer, weed killers, and seed, but hard to make sense of which products are right for you. Before you shop, here are a few thoughts that may help sort things out.
Even though they only share two letters in common, comparison always spells trouble. We all know it’s wrong to compare oneself to a professional model. In a similar vein, it’s a losing proposition to see a putting green as an example of what a lawn should look like. Golf courses only exist thanks to turf experts and massive budgets. With a few facts and a little maintenance, though, we can have very nice-looking lawns. In the words of Dr. Frank Rossi, a leading Cornell Turfgrass Science researcher,
“Chances are you can grow a pretty good lawn without using insecticides, fungicides, or herbicides. You may even be able to do it using little or no chemical fertilizer, if that's your goal. Will your lawn look like a putting green? No. Will it stand up to wear and tear like a professionally managed soccer field? Not a chance. But if you arm yourself with an understanding of what grasses need to thrive, and commit to a long-term plan to meet those needs, you can grow a perfectly acceptable lawn...”
Know your soil
Soil pH test kit. Result? Acidic. Photo: Susy Morris, Creative Commons, some rights reserved
Get the dirt on your soil. If your grass looks bedraggled, fertilizer may not be the answer; in fact, early-season nitrogen can weaken grass and make lawns worse in the long run. At the very least, get a soil pH test – a pH that is lower (more acidic) than 6.0, or above (more alkaline) than 7.0 will hinder plants’ ability to absorb nutrients. I’ve done hundreds of homeowner soil tests, and the vast majority have had pH values too high for healthy lawns due to annual lime treatments. Lime is only good if it’s needed.
If it has been more than three years since the soil was tested, you may want to invest in a lab analysis. For less than twenty dollars you can get nutrient levels, with specific recommendations, plus pH and salt content. This last item may seem odd, but fertilizers, herbicides, wood ash and deicing agents all contain salts, which damage soil structure, harm microbes, and aggravate water stress. Only fertilize based on soil test results, and ideally, only use nitrogen in the fall.
Nature abhors a vacuum, which is why I hide mine in a closet – no sense offending nature if you can avoid it. This hatred of emptiness means that if you don’t re-seed bare (and weak) spots in the lawn, nature will fill it with whatever is handy, probably weeds. Edging along sidewalks and driveways may produce a look you want, but it also produces a lot of bare earth. If you have a weed issue, especially crabgrass, try to break this habit.
Don't give your lawn a buzzcut
Don't give your lawn a buzzcut. Mowing to 3.5 to 4 inches makes a healthier and more resilient lawn. Photo: Wallpaper Flare
Another type of vacuum is a close-cropped lawn. Not only does close mowing lead to weak, stunted grass roots (and thus plants), it allows the sun full access to the soil. This gives weeds a tremendous advantage. Have trouble with ground ivy? Put away the vacuum. Stop shaving the soil and start mowing the grass.
The most important thing you can give your lawn is more of its hair. Studies show that mowing grass at 3.5 to 4 inches high will lead to a vast improvement in lawn health. Leaving grass at this height will greatly reduce lawn weed pressure, diseases, and fertilizer requirements.
If you need to use herbicides to reduce weeds, follow the label instructions closely. Some broadleaf (selective) herbicides contain chemicals that may stress or injure trees. Pre-emergent herbicides inhibit weed germination, and are used for crabgrass control. Pre-emergent products are only good when applied around the time forsythias are in bloom.
Another tip is to only mow a third of the grass at a time. For example, to maintain a 3.5-inch turf height, mow when the grass gets five inches high. Keep the blades sharp. This can help reduce disease, plus it looks nicer and saves on gas. And it almost goes without saying that grass clippings belong to the lawn, not the landfill. Leave the clippings. They are your fertilizer.
Northern NY State is home to five species of grubs, which can become a problem if there are more than ten per square foot of lawn. Several nontoxic and low-toxicity treatments have come on the market in the past few years, but timing varies for all of them. Milky Spore treatment is safe, but Cornell Extension experts say it is too cool up north for this option, so save your bread.
You can find a free, comprehensive booklet entitled “Lawn Care” at http://hort.cornell.edu/turf/lawn-care.pdf
It would contribute to a better world to teach kids to stay grounded, and to let the grass get high.