The Spokesman-Review


The Grass Grows Greener Which Fertilizer? How To Water And Mow? So Many Concerns When It Comes To Lawn Care

SATURDAY, MAY 17, 1997

A lawn is one of the most beneficial “plants” in our landscape. It traps pollutants, provides oxygen, controls erosion, keeps dust particles down and provides a cooling atmosphere all summer long.

Yet the maintenance of this workhorse is probably dreaded more than any other garden chore. It requires constant care: mowing, watering, fertilizer, herbicides, fungicides and pesticides. Or does it?

The secret behind a beautiful lawn is a healthy lawn. The key is to know how to create and maintain such a lawn.

We must first start with the foundation: the soil. Most plants flourish in rich, loose, well-drained soil, and this includes lawn.

However, unless we’re planting on a former wheat field, most of us don’t have such soil. We work with what nature has given us. In most cases, it’s either sand, (basically incapable of holding nutrients or water) or clay (which retains too much water).

To achieve a rich soil, we need to add an abundance of organic matter: peat moss, rotted sawdust, compost, grass clippings, etc. When we consider how much area a lawn covers, adding organic matter can be expensive. But consider the flip side: Constantly watering, fertilizing and adding chemical sprays to the lawn can prove to be an ongoing expensive proposition.

What we don’t want to do with soil preparation is what unfortunately is done too often. We smooth out our existing soil with a heavy grader, compacting it, and then add a couple inches of sandy loam, which in most cases is just sand. Sure, the grass will grow, but it won’t be healthy.

Prior to seeding, hydroseeding or sodding a lawn, we must try to improve the existing soil. Incorporate at least 4 inches of organic matter mentioned above into the top 8 inches of soil. Till it until all chunks are broken down. Rake it smooth and plant.

What can be done to improve the soil of existing lawns? Top dress each year with about a half-inch of peat moss or simply leave the grass clippings on the lawn. If only a third to a half of the blade is cut off with each mowing, the clippings will break down quickly, adding nitrogen and organic matter into the soil. What a great deal - automatic and free top dressing every time you mow.

Fertilizer

Before we start applying copious amounts of fertilizer, we should understand how grass grows. Most of us think that grass simply pulls up nutrients and water from the soil and lives happily ever after. Not quite so.

Grass, like other green leaf plants, manufactures food through its leaves. This process is called photosynthesis. A lawn cut tall (1-1/2 to 2 inches), has more green surface to capture the sun’s rays than a lawn mowed short. The manufactured food is stored in the roots as energy. This stored energy produces more roots and more leaf blades.

If the lawn is mowed short, photosynthesis is diminished and the root system suffers.

To make a long story short, or a short story long … the taller the grass, the deeper and stronger the root system. The shorter the grass, the shorter and weaker the root system.

So does this mean we don’t have to fertilize? Not necessarily. In the early spring, a healthy lawn’s stored energy goes into creating new green blades so fertilizing should not be necessary. During the summer months, the lawn continues to manufacture food.

By fall, much of the energy has been depleted and an application of fertilizer can be a much appreciated boost. A balanced chemical fertilizer (all three numbers) or an organic fertilizer should be added mid- to late September. This will help ensure a healthy lawn for next spring’s growth.

If your lawn is not responding in the spring, then apply a mid- to late May fertilization. A second fertilization can be applied if need be in late June.

Try not to apply fertilizer during the heat of the summer - July and August. During this time, the lawn slows down its growth rate. A heavy fertilization may simply encourage weeds. And then, of course, end with the important fertilization in the fall.

Do we use chemical or organic fertilizers? The lawn really doesn’t care. It can only use nutrients in a soluble form and only when it needs them. However, the soil does care. Chemical fertilizers leave behind salt, which tends to kill off microorganisms. Organic fertilizers help to build and keep micro populations healthy. As with anything we do, create a balance. Alternate between chemical and organic fertilizers.

Mowing

Though a reel mower makes a cleaner cut, the rotary mower works faster. For this reason, it seems to be the preferred machine.

Along with routine maintenance on the rotary mowers, it’s important that the blade be kept sharpened. This may require changing the blade about every six weeks. A dull blade butchers the lawn, leaving it ragged and open to disease pathogens.

In order to get an even cut, mow the lawn when the grass is standing tall. To ensure this, mow when the lawn is dry and in different directions each time you mow.

Try never to cut off more than a third to a half of the blade with each mowing. This is very difficult to accomplish, especially if we only mow once a week.

If a mulching mower isn’t used and you’re cutting off more than half the blade, then collect the clippings. Otherwise, leave them on the grass. They do not add to thatch. However, if long clippings are left, they can matt on top of the lawn and choke out the grass.

Watering

I wish there were a simple answer for watering, but there isn’t. The only constant is that lawn requires water to dissolve soil nutrients and to transport them through its system. But how much water do we apply and how do we apply it? These are the stumbling blocks.

Weather usually dictates how much and when to water. In the spring, the soil is usually moist and the days are cool, thus preventing much evaporation. Obviously, very little, if any, watering will need to be done then.

By summer, the days are usually hot, dry and many times windy. The soil dries quickly. If the roots are deep, they can usually handle this situation. If the roots are shallow, they will require frequent watering - in worst cases, every day.

Soil type also dictates when and how much to water. As was said before, sandy soils have very little if any water-holding capability. Clay soil seems to hold water forever. A loam or organic soil will hold water like a sponge, allowing excess water to drain away.

The type of sprinkler also dictates how much water will go onto the grass. Ideally, we would like to see 1 inch of water applied once a week. But the amount of water isn’t as critical as how well it penetrates the soil. If water is applied too quickly, it has a tendency to puddle. If applied slowly, it will move easily through the soil.

Whichever type of sprinkler is used, make sure the water overlaps to ensure proper coverage. Always take into consideration wind and how it moves and evaporates the water.

And as far as that time of day to water, early morning watering is the best. It allows time for excess moisture to evaporate. Diseases can develop when the lawn is wet, especially during the night hours.

However, if the only time you can move the sprinklers around is after work or if the water pressure is better at night, then that’s the time to water. A healthy lawn can be watered at any time. A stressed lawn should be watered in the morning hours after dawn.

Dethatching vs. core aeration

Dethatching/power raking should only be done on very old lawns. Bluegrass roots have a tendency to get caught up in thatch. Power raking can pull up those roots, leaving barren areas behind. These areas are prime for weeds and weedy grasses, which can take over before the bluegrass can recover.

The best recommendation is to core aerate the lawn twice a year if possible. If you can only handle this operation once a year, then do it in the spring when the soil is moist, but not soggy. Core aeration opens the lawn to air, fertilizer and water.

Seeding and sodding

And finally, a word on seeding and sodding. The normal lawn grown in our region is a mixture of bluegrass and fescue. Look for blends of two types of bluegrass, one type of fescue, annual rye and less than 4 percent weed seed for the sunny lawn.

Shade lawn should have a mixture of two varieties of fescue, one bluegrass, annual rye and less than 4 percent weed seed. Remember, all lawn grasses require some sun. If your lawn is continually invaded by moss and algae and you are growing a shade lawn in that area, remove the lawn and enjoy the moss.

If you are sodding, prepare the soil as if you were seeding. Once the sod is laid, core aerate three weeks later, twice more that year and three times a year for the next two years. This will help break up the different soil layers and hopefully prevent disease.

Most importantly, enjoy your lawn. It’s great for the environment, it’s great for kids and it’s great for you.

, DataTimes ILLUSTRATION: Color photo


 

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