Growing Green: A strong, green lawn
May your lawn be strong and green.
However, if you feel that you need some advice, here are some tips that may help.
There are a few things you can do immediately to promote the health of your lawn.
First, start the season off right with a sharp mower blade. A dull blade will fray the ends of the grass and make it more difficult for the plant to heal after each cutting, providing ready access for disease organisms to enter the leaves. Also, frayed ends can look ragged and give a lawn a whitish cast.
Another thing you can do is to raise the height of your mower blade so that you are cutting the grass at two- to three-inches-tall. The grass needs green leaf tissue for photosynthesis, the process by which the plant makes its food. Cutting your grass too low weakens it and it becomes less able to resist weed infiltration and attack by insects and disease.
Frequency of mowing is another important consideration in your maintenance program. Ideally, you want to remove one-fourth to one-third of the plant at each mowing, but not more.
If you cut infrequently and the grass is tall, you will be removing a very large portion of the total plant at mowing time. The plant reacts to drastic mowing by producing much less food through photosynthesis and begins to deplete its reserves in the roots, weakening the stand. Also, the piles of clippings left after infrequent mowings can smother grass plants if left to lie on the lawn.
Most lawns in the Lehigh Valley consist of a mixture of bluegrass, fescue and ryegrass species. These three species are what are called cool-season grasses. They grow best in cooler weather and go dormant in the summer when the weather gets very hot and dry.
The dormant period is a natural defense which keeps the plants alive when conditions are too harsh for survival. Some people try to prevent their lawns from becoming dormant to avoid the dry, brown appearance during mid-summer.
Keep in mind that any attempts to prevent this natural occurrence can be very harmful to the health of lawn grasses. If you continue to provide your grass with lots of fertilizer and water during the summer, you are inviting many fungal disease problems that thrive on lush green grass, high nitrogen and warm temperatures.
Additionally, if you decide to take a week’s vacation and abandon the grass during a dry spell, much of the grass can die because it was not prepared to survive without supplemental water.
Some reasons for brown patches in lawns could be damage from snow mold, grubs or fungal diseases the previous summer. Reseed these areas now by removing the dead debris and scratching the soil with a rake. Sprinkle a couple of handfuls of grass seed on the patch and lightly rake it in to assure good contact with the soil. Use a very light layer of compost or clean straw as a mulch over the new seed.
It is beneficial to try to determine the cause of the dead patches to avoid having the problem next year. Check for grubs by peeling away a one-foot-square section of sod in several areas of your lawn and examining the root zone.
If you find an average of eight or more grubs per square-foot, plan to treat the grubs with an insecticide when the grubs are most vulnerable, in late May to early June or in late August to early September.
If you do not find many grubs, discourage fungal disease problems by being careful not to fertilize your grass in the heat of the summer.
Carefully watch these areas to observe if a similar problem happens this growing season. The best time for diagnosis is when the disease is active.
Most of all, take time to enjoy your lawn this year, even if it is not perfect.
“Growing Green” is contributed by Lehigh County Extension Office Staff and Master Gardeners. Information: 610-391-9840, 610-813-6613