Gardening Help FAQs

Here are answers to some of the most common questions we receive about garden plants. You will find concise information on general gardening techniques as well as plant selection and care. For detailed information on specific plant pests and problems refer to our Common Garden Pests and Problems page.

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Horticulture Questions and Answers

How often and how high should I mow my cool-season lawn?

Mowing frequency and height are key maintenance practices in keeping grass uniform, attractive, and most importantly healthy. The height and frequency of the cut influences the health and vitality of cool-season grasses in many ways.

Cool-season grasses such as Kentucky bluegrass, turf-type tall fescues, and fine leaf fescues should be mowed a minimum of once a week during the growing season. More frequent mowing may be required in the spring and fall when growth is most active. Mow frequently enough so that you remove no more than one- third of the total plant height in one mowing.

During hot summer months less frequent mowing may be needed. Avoid additional stress to your cool-season lawn in hot weather by mowing later in the day. Changing the direction of mowing each time you cut the grass is also a good maintenance practice.

When it comes to height, cool-season grasses are best mowed at heights of 2 ½ to 3 ½ inches above the soil line. The taller 3 ½ inch cut is most beneficial and recommended for the turf-type tall fescue blends.

To adjust your mower to the right height, place it on a hard surface and measure from the blade to the hard surface. In many cases, you will find that the highest setting on your lawn mower is the preferred cutting height.

It is important to have a sharp mower blade. Dull blades tear and fray the leaf tips rather than cutting them, and will give your lawn a tan or brownish appearance. Dull mower blades also take more power or fuel to operate.

The following are some benefits to a taller cut of your cool-season grass:

     *  It shades the soil and reduces weed problems 
     *  Cool-season grasses prefer the cooler soil temperatures created by the shaded soil
     *  A taller cut encourages a deeper root system aiding in the vitality of the grass
     *  The deeper root system increases water uptake during dry periods
     *  Taller cut cool-season grass is less susceptible to injury from drought and disease
     *  Heavily shaded and dry sunny slopes experience less stress with a taller cut.

Newly seeded or sodded lawns should not be allowed to grow excessively long before beginning mowing. Always follow the one-third rule mentioned above. Mowing at this time aids in the strengthening and thickening of the new grass.

When you cut the grass, practice grasscycling and return the clippings to the lawn. For the benefits of grasscycling, see our FAQ on "Should I collect my grass clippings?"