University of Illinois Extension
Bruce Spangeberg

These articles are written to apply to the northeastern corner of Illinois. Problems and timing may not apply outside of this area.

Stateline Yard & Garden

Area and Moisture Important in Lawn Care

September 16, 1999

In discussing early fall lawn care, seeding, overseeding, and fertilizing, two items are often taken for granted. One is adequate soil moisture; the other is the area of the lawn. Both are crucial to assure success in caring for your lawn.

Most of northern Illinois has been dry for several weeks. Even though the calendar says early September is a great time for lawn care, without soil moisture things are not likely to work well. For example, whether planting an entire new lawn or overseeding as part of renovating an existing lawn, lack of soil moisture means the success is likely to be poor. Even if slit-seeding, which assures excellent seed to soil contact, results will be poor if the soil stays dry.

The same holds true when fertilizing. Grasses need to be actively growing to use the fertilizer. Temperatures have been cool, which is ideal for growth, but water is also needed. So the bottom line is, lawns need to be watered if rainfall is not adequate.

The other factor often overlooked is the size of lawns. This is needed when calculating how much fertilizer to apply, in addition to how much seed or sod to purchase. Rates for turfgrass management are expressed as units per 1,000 square feet of area. Do you know how many square feet are in your lawn?

There are 43,560 square feet in an acre of land. If you have a 1/4 acre lot, you are starting with about 10,890 square feet of land. Subtract the area of the house, driveway, patio, landscape beds, and other non-lawn areas. This leaves you with the square footage of lawn. Unless changes are made adding or deleting lawn, this figure will not change so write it down and remember it.

Once the area of lawn is known, the proper amount of fertilizer needed can be determined. For most applications, a rate of one pound of nitrogen per 1,000 square feet is suggested. If the fertilizer were 20 percent nitrogen, it would take five pounds of fertilizer product per 1,000 square feet to supply this one pound rate. If your lawn measures 6,000 square feet, you'd need about 30 pounds to do the job (six times five pounds/1,000).

Most fertilizer products give an estimation of what area the bag will cover. This guideline is usually based on supplying about one pound of nitrogen per 1,000 square feet.

Finally, pay attention to rates for other yard and garden applications. Many flower and vegetable recommendations are expressed per 100 square feet, or 10 by 10-foot area. In some cases, products may also be expressed per acre, although this generally applies more toward commercial crop uses.


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