When it comes to caring for a lawn affected by insects and diseases, the solution is often to apply products like fungicides and insecticides which can both prevent and remove the damage caused by these intruders.
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There are many factors at play when it comes to the health of your lawn. One of these factors is your ability to recognize potential damage to your lawn from disease and damaging insects.
While you may have spent the spring overseeding, mowing, and fertilizing your yard, grass diseases and damaging insects can still show up in the middle of summer.
Be Aware of Changes in Your Lawn
During the hot summer months of June, July, and August, keep an eye out for subtle changes in your yard. You’ll want to recognize and respond to these changes quickly so that extensive damage does not occur.
For example, grubs gnaw on grass roots before they turn into Japanese beetles or European chafers, a process which can cause damage to your grass. It is important to be aware of the changes caused by this damage before the grubs can take over your entire lawn.
Conversely, hot and humid heat waves which arrive in July and August, can force your cool-season grass into dormancy. Noticing this damage will allow you to be able to make the right changes in your lawn care practices in order to keep the dormant grass alive.
Cool-Season Lawn Diseases
Most lawn diseases, many of which are fungal infections, begin in the summer after a period of hot, humid weather.
Hot, humid weather helps fungus to grow and destroy your lawn. You can apply a fungicide in the spring, when disease pressure is low, for prevention, and in the summer, when disease pressure is high, as a curative action. Doing this, in addition to smart lawn management throughout the summer, will assist your lawn in combating fungus growth.
Here are two common lawn diseases that pop up in mid-summer:
- Brown patch
Many cool-season lawns have a mixture of tall fescue, Kentucky bluegrass, and perennial ryegrass. These grasses are susceptible to brown patch. Brown patch attacks the foliage with brown or reddish tan spots that turn into large patches on your lawn.
Brown patch occurs when nighttime temperatures rise above 60°F, and daytime temperatures reach 90°F or more. Stretches of hot temperatures like these in culmination with humid weather help brown patch to spread throughout your yard.
To prevent brown patch from forming, or respond to it if it does form, you can add a fungicide preventer to your lawn.
- Pythium blight
A lawn with heat or drought stress becomes susceptible to Pythium blight. Additionally, hot, wet weather plays a part in your cool-season grass getting the disease because it strikes grass that stays wet.
You can help your lawn fend off Pythium blight by fixing any drainage problems on your property so that water percolates into the soil and doesn’t flood the lawn. Watering your lawn infrequently so that it gets the appropriate 1-2” a week will also help to fend off this unwanted disease.
Pesky Bugs That Destroy Lawns
In addition to the diseases that you must watch for in your lawn, there are two types of insects to be aware of, as they can also harm your lawn. Two of these insect species are chewing insects and sucking insects.
- Chewing insects
A lawn grub (left) is the larvae of a beetle (right).
Chewing insects like grubs, which later turn into beetles, eat the grass’s roots, killing your lawn.
You can tell when you have grubs by pulling back a section of your grass. If it pulls up like a carpet, and you see 10 or more white, C-shaped critters in one square foot, then you have a grub problem.
To avoid grubs, put down a grub preventer in late June when the larvae are active.
Sod webworms are another chewing pest that cause brown patches in lawns.
A sod webworm is commonly considered the caterpillar stage of a moth’s life cycle.
Webworms do their chewing in spring, unlike the moths that fly low to the ground in late summer. Despite their early action, you’ll only notice webworm damage in late July or August.
You may think that the brown patches caused by webworm damage are cool-season grasses in dormancy. Yet, if you dig into the thatch, you’ll find silk webs, evidence that sod webworms are present.
To ward off these damaging pests, there are insecticides available which target webworms in the spring.
- Sucking insects
Though chinch bugs are a type of beetle, they do not have a larvae stage and they only grow to about a sixth of an inch long.
Sucking insects draw the fluid out of the grass plant and replace it with their saliva, consequently killing the plant. Chinch bugs are an example of a sucking insect.
Damage caused by chinch bugs shows as browned grass, much like the browned grass caused by countless other lawn problems.
To find out whether the browning of your lawn is a result of chinch bugs, follow these simple steps:
- First, take a can and cut off both ends so that it is a hollow cylinder.
- Next, drive the cylinder into the grass so that it cuts through the thatch and into the soil. This can be done simply by turning the can back and forth, as the sharp metal of the ends should cut easily through the grass.
- Once the can stands alone in the grass, fill it with water. Keep refilling until water stops absorbing into the grass and can stay level around half of an inch from the top of the can.
- After the can stays filled for about a minute or two, watch for chinch bugs to surface. These bugs are small, about an eighth of an inch long, and sport white spotted wings. If you see these bugs, it may be time to lay down insect preventatives and curatives so that your grass can return to health.
When you are attentive to changes and follow proper maintenance techniques in your lawn, you give your lawn the best opportunity to thrive against the destructive effects of insects and disease.