May Lawn Care Tips

May is a great month for growth. As the temperatures continue to rise, the flowers bloom and your lawn continues to grow and green! You should really start to reap the rewards of a well kept lawn with your family and friends. Mowing and watering should be more frequent this month. Also, May is a great month to help prevent summer annual weeds, so if you haven't applied a pre-emergence herbicide already, now is the time for it.


If you haven't adjusted your sprinkler system, you might start seeing brown spots this month because of uneven coverage. No system is perfect and needs readjusting at least on an annual basis.

Also remember, it's important in the spring time to train your root system. A good deep watering (about 10 inches of moist soil), between one and two times a week will be sufficient for your lawn. However, it may be necessary to water more frequently as the temperatures rise and the rain slows leaving your soil dry. Frequent and shallow watering early in the year, causes your roots to remain shallow which makes your lawn dependent on frequent watering.

How do I know if my soil is dry?

First, look for a dirty green that doesn't spring back quickly when stepped upon. You can confirm dryness by probing the soil with a screwdriver or a butter knife. If it is relatively hard to push in and moist soil doesn't stick to the probe, it's too dry.


The hotter the weather, the more helpful it is to mow at the second to the highest setting (2 1/2 to 3 inches long). To insure that you don't remove too much green, mow off only 1/3 of the blade at a time, since most of the green in your lawn is located in the top portion of the blade. This helps to conserve water, strengthen the root system, and help crowd out potential weeds.


In May, the weeds in your lawn are still mostly perennials such as Dandelions, Thistle or Mallow. However, there is a continually increasing number of annual weeds. The broad-leaf weeds can be sprayed with a selective herbicide. Any grassy weeds would need to be sprayed with a non-selective herbicide such as Roundup and the lawn replanted in that area.

In June you may start seeing crabgrass and other summer annuals in the cracks of your sidewalk or driveway. This is an indicator of the weeds that may soon infiltrate your lawn. Therefore, applying a pre-emergence herbicide this month will help prevent many of these weed-seeds from taking root and infesting your lawn.

Orchard grass has often been mistaken for crabgrass, however, there is no crabgrass in lawns during this time of year. It is a summer annual weed, most commonly seen during July and August and begins to die as the temperatures fall below freezing. A pre-emergence in April or May will help prevent most of last years seeds from germinating.

  • Clover

  • Dandelions

  • Mallow

  • Morning Glory

  • Orchardgrass

  • Thistle

  • Violets

  • Yarrow


We usually don't see many insects damaging lawns during May, however, on occasion we have seen evidence of Cranberry Girdler, White Grub or Sod Webworm.

How do I know if I have an insect problem?

If you see an area of your lawn turning brown, check for insects. Pull on these areas with your whole hand. If insects are at fault, it will pull up like rug and you will see little white larvae on the soil.

How do I solve my insect problem?

To control the problem, apply insecticide directly to the affected areas and check back weekly for improvement. Repeat this until all signs of insect activity are gone. This means that the brown spots have stopped spreading, there is evidence of new growth, and the the larvae are lethargic or dead.

  • Cranberry Girdler

  • Sod Webworm

  • White Grub


While we don't see many cases of disease during May, helminthosporium, or, "melting out" may be seen in your lawn. It is characterized by a browning of the blade of grass, with purple in the margins between the brown and green areas. To help prevent and treat helminthosporium, aerate to reduce thatch in the early spring, water infrequently and deeply, and mow high.

If you do see signs of helminthosporium, give Turf Plus a call and we'll come out and take care of it for you!