A Greener View by Jeff Rugg

Q: In a recent article you mentioned mowing the lawn grass as high as possible. I think my husband mows it too low. It has a close-cropped appearance that he likes. It is lower than all the lawns in the neighborhood. When I walk on it, it is not comfortable like a longer grass would be. What reasons can I give him to mow the grass higher?

A: There are several reasons that lawn grasses should be mowed higher than many people actually mow their grass. If left un-mowed, most lawn grasses would grow to a height 1.5 to 3 feet tall. When we mow them, we are reducing the leaves at the top of the plant, which reduces the amount of food the plant can produce. Less food means fewer roots can be supported. Fewer roots means less water will be available to the top of the plant when the weather is drier.

Most plants, including other kinds of ornamental and native grasses, can't tolerate repeated close mowings and would die. Lawn grasses tolerate mowing, but they potentially need extra care with fertilizing, watering and control of insects, weeds and diseases in order to maintain their health under such stressful conditions. The taller the lawn grass is allowed to grow, the fewer chemical products will be required to keep it healthy.

The taller the plant is after mowing, the more leaves there are, which means a stronger, healthier plant with a bigger root system. Taller plants shade the soil around themselves, which conserves water and saves money. Shade also can prevent the sprouting of weed seeds, which means less weed killer is needed. A well-rooted grass plant also inhibits weed growth. A larger root system draws water from a larger volume of soil, so the plant is less stressed by drought and needs to be watered less often.

Mowing too low not only does the opposite of all these things, it can damage the crown of the plant where the leaves sprout. The damaged crown can be killed outright or become more susceptible to insect and disease problems.

Mowing too low and scalping the grass plant happens on lawns where mower wheels are not set properly and one side of the mower blade is too low. It can happen along an edge of the flowerbed where one wheel drops into the bed and one stays on the lawn.

Scalping the lawn often occurs through the improper use of string trimmers. String trimmers should not be held horizontally along the edges of walks and drives or around fence posts and trees.

They need to be held so the string only cuts a thin line along the edge and not so that it mows a wide scalped path.

Cool-season grasses in the northern states, such as bluegrasses, fescues and ryegrasses, should be mowed 3-4 inches tall. Bluegrass and Chewings Fescue can be mowed at 2 inches, but much more care will be required to keep them healthy.

Warm-season grasses, such as Bahia, Centipede, St. Augustine and Zoysia, can all be mowed at 2-3 inches. Bermuda grass can be kept 1-2 inches tall, and Seashore Paspalum can be mowed at .75-1 inch, while Bentgrass is used on golf greens at under a half-inch.

While there is a range for each grass, and many can be cut lower with a lot of work, the taller a grass is mowed, the better it is for the health of the plant.

Q: While helping clean out my father's garage, we found some old weed killers and insecticides that were many years old. Are they still good? If we can't or don't want to use them, what do we do with them?

A: If you can read the label clearly enough to read who the manufacturer is, you should call them first. They can tell you what to do to use or dispose of the products. They can get you a new label that you can read.

If you can't read the label or don't even know what the product is, you will need to find a local disposal company. Your state EPA or state Department of Agriculture would be the first places to call to find out who can dispose of these chemicals. Under no circumstances should you just drop these products into the garbage.

It might be that the products are no longer registered for use, making them possibly illegal to use. If they are older than about five years, most products will have lost most of their potency, but are still illegal to dispose of improperly. If they are partially effective, they can still be used, but they might not work as well and need to be reapplied. Old powdered or granular products may not mix properly with water, making them impossible to use.

In the meantime before you dispose of or use them, all of these products should be stored in a safe place out of reach of children and of flooding. They should be stored in dry sealed containers if the old containers are falling apart, but they should never be stored in any food containers that could confuse children.

To keep this from happening, it is recommended that people only buy the amount of product they will use in one year. Small bottles or boxes of pesticides are much better than buying in bulk. Use up what you have before buying more, even if you must miss a sale.

E-mail questions to Jeff Rugg, Kendall County unit educator, University of Illinois Extension at jrugg@uiuc.edu. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.

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