Monday, August 3, 2015

Triple threat

At this time of the year it can be hard to tell what is affecting your lawn.
If you are not watering, or you haven't been cutting properly, the issues may be many.
In some cases you may not know until the fall, when lawns begin to recover from the summer heat and your grass does not, what the cause is. But here are the big three in terms of summer grass problems.

Drought stress, summer patch and brown patch are the most common. Simply, if it's not raining and you're not watering, the lawn will begin to enter into a state of dormancy. If it does, it is best to just let it run its course and revive it come September when cooler temperatures return. Turf diseases like brown patch, on the other hand, show up with shifts in humidity and affect mostly Kentucky Blue, bent and some fescue grass types. To avoid all turf diseases, it is best to water the lawn early morning instead of evening, wait for the affected area to grow out and bag clippings when cutting, which should be, every other week at this point.

Chinch bugs are top feeding insects that love it hot and love it dry. They have been active for about a month and can destroy a lawn in short order if not dealt with. Again, if your lawn is predominately  a non-endophytic grass-type like Kentucky Blue grass, or you're cutting your lawn too short you are susceptible. Although, I have seen this insect take out fescue lawns in recent years. Your best defence is to douse the affected areas with soapy water, avoid those who preach nematodes for control and call a professional if the damage continues. Every fall make sure you over-seed with endophytic grass cultivars.

Sod webworm, white grub are root feeding insects. If your lawn is infected- and by that I mean ten grubs per square foot, or six per with webworm, damage will soon be evident as we are entering a new cycle of larvae hatching.

With webworm, look for baseball-sized, circular, brown patches you may have mistaken for pet urine burns. The webworms tunnels may also be evident as is their green pellet excrement known as "frass".

With white grub those circular patches will snake outward and the grass will come up easily like a carpet. You may also see signs of predator digging (raccoons, skunks)

The most widely used treatments are nematodes, (SC for webworm, HB for grubs). You need  to know what insect you are dealing with, but both strains of nematode must be applied in ideal conditions, kept refrigerated until use and they have an expiration date. It is of the utmost importance that you follow directions if you choose this method of control. Even then studies range between 50%- 70% control which might be ok when playing roulette, but do you really want to gamble with your lawn?

Remember, this is Mother Nature's top of the batting order and if you want to make the post season with healthy turf, you'll need to prepare your defence for anything that is thrown at you.