How to Spot Some of the Most Common Early Summer Turfgrass Diseases

During the early summer when the warmer weather hits, we typically see a number of common turfgrass diseases. Here are a few tips on how to spot these troublesome diseases.

In the early part of summer, we typically start to see a noticeable shift in weather patterns. Those cooler spring days start to become consistently warmer – and we start to see warmer nights, too. This major change can trigger several common turfgrass diseases, ultimately leading to an increase in calls to our local offices from customers requesting a visit from one of our turf care experts.

Leaf blight

On northern bluegrass lawns, leaf blight is one of the most difficult early summer diseases to manage, mainly because it can happen so quickly and affect large areas that resemble a chemical burn. Oftentimes leaf blight may impact one person’s lawn and not the lawn right next door, simply because of isolated cultural conditions (e.g. a dull mower blade) which can influence the spread of the disease or the severity of it from one lawn to another.

Leaf blight disease generally enters the grass plants after evening mowing followed by excessive night watering. In heavily infested patches, the fungus damages the lawn in circular patches that often form large bleached areas. Closer inspection of the plant reveals individual leaves dying from the tips down.

Lawns react much like a house plant when they get a leaf disease: the first reaction of the plant is to drop the diseased leaf before the disease can enter the main part of the plant. Turf is similar in that it will shed the infected leaf by thinning the lawn out. When conditions improve, the lawn will regrow the leaf and start to fill back in. Sometimes this can take weeks and other times it can take longer depending on the weather patterns present.

The second disease we usually see at this time of year — although mainly further south where tall fescue and more southern grasses like St. Augustines are grown — is brown patch. The causal agent of brown patch is the fungus Rhizoctonia solani, and symptoms of the disease include patches of dead and dying grass. The turf in these patches often appears “sunken.” The center of diseased patches may appear less affected, and it may show the frog-eye symptoms commonly associated with summer patch. However, look for the characteristic brown-patch leaf spot on individual blades. It will help distinguish brown patch from summer patch. Also, brown-patch-affected turf appears less matted.

So what is the best treatment available to prevent these two diseases from developing? The most important thing is to ensure you have a sharp mower blade, as this will help the grass heal quickly before the disease has a chance to enter the leaf blade and infect the turfgrass.

The second thing is avoid overwatering the lawn at this time of year. Some customers with irrigation systems will have them on and watering when it isn’t required. Too much water is a major issue that contributes to the formation of these diseases. Remember: water in the morning and avoid evening watering or mowing when the lawn is wet.

Lastly, a healthy, well-maintained lawn is the best defense against harmful disease. It is important to keep the lawn fertilized regularly. Although out of your control, improved weather conditions will also greatly assist in the lawn recovering from leaf disease. Once we get into the real heat of summer, these diseases will disappear on their own…although that just means others more suited for the heat may appear.

If you have any questions about your lawn? Weed Man would be happy to help you. Find your local Weed Man using our locator map HERE.

Keep those lawns healthy,

Chris

 

Summer Drought & Your Lawn

The summer drought conditions this year have been pretty severe in a number of areas and we’re only into the early part of July. With it being so dry in May and June, it can’t help but have an effect on your lawn now and into the fall.

In March I wrote a blog that started with “If the weather predictions come to fruition this year due to the strong El Niño, it looks like we will have a drier and warmer-than-normal summer in 2016.” So far, that is exactly what is happening in a lot of areas in the U.S. The past few years (at least in the eastern parts of the U.S.) we have been pretty lucky in that we had fairly regular rainfall and cooler summers. So it may come as no surprise that we were due for some drier, warmer weather with some severe drought. So what can you do to help the lawn through this hotter and drier weather?

As I mentioned in my March blog, one of the things you could have done to prepare for the hot and dry summer was getting your lawn as healthy as possible in the spring prior to having to experience the summer heat and drought. “You definitely don’t want to skip any fertilizer applications this spring or early this summer as the lawn will need it. Fertilizer is going to be very important in setting up the lawn to withstand the stress of a hot summer by giving it the key nutrients it needs to help it stay healthy when its under stress.”

That being said if you are watering your lawn through the summer and keeping it green, the lawn will still need to be fertilized as it will utilize those nutrients to maintain its healthy state. If you decide not to water it and therefore let it turn brown, the amount of nutrients it requires will be a lot less and fertilizing it may be unnecessary. However, if you use a slow-release fertilizer, not to worry, those nutrients should stay there for the plant to utilize when you do get rain, which will encourage the grass to grow again.

Watering will have a big impact on a lawn’s appearance and proper watering is a must if you are going to keep the turf healthy until more regular rainfall occurs. Almost all grasses can withstand a certain amount of drought. For example, bluegrass can withstand drought for up to 6 weeks before injury. As you see in the picture below, this lawn had not been watered for quite a while and the lawn did not recover. The end result? Most of it had to be re-sodded that fall.

Remember that there are a lot of ways not to water your lawn and it is the most misunderstood practice for homeowners. The biggest mistake occurs when homeowners irrigate their lawn every day for 20 minutes (simply because that is the way most irrigation systems are set up), without realizing that this type of light watering can lead to shallow rooting and disease. Shallow rooting creates a weaker plant that is prone to environmental stresses, which can result in an increase in lawn diseases. Also, not allowing the lawn to dry out for a period of time can also increase the chance of disease. This ultimately leads to discoloration of the lawn and poor visual quality. Watering at night is often the biggest reason for the presence of disease on the lawn.

When it comes to watering your lawn and helping it look its best, water only when the lawn needs it and be sure to water deeply. Watering deeply in the morning when the lawn requires it will give your turf the opportunity to dry out and prevent lawn diseases in the process.

Mowing can also influence the health of the turf, so when it’s hot and dry out, it’s a great idea to mow your lawn as high as you can. The longer the turf is maintained, the healthier it will be, as it will have a much deeper rooting system. This deeper root system will better utilize underground water supply and find its own water and remain healthier overall.

Click HERE to view the NOAA National Precipitation Map for June by %, to see how your area is doing for Rainfall.

Questions about your lawn? Weed Man would be happy to help you. Find your local Weed Man using our locator map HERE.

Keep those lawns healthy,

Chris