Drought May Not Be the Reason for Your Turf Decline
Posted: September 15, 2016
So, did drought cause all of the lawn problems that we are seeing right now? I can tell you for certain that the answer is no.
One of the first things to keep in mind about cool season turfgrasses is their growth cycle. The species of turf predominantly used in Pennsylvania are Kentucky bluegrass, perennial ryegrass, tall fescue, fine fescue, and creeping bentgrass (on golf courses). All of these turfgrasses have a flush of growth in the spring, a decline in growth in the summer, and a large rebound in growth in the fall. In fact, cool season turfgrasses grow the most (and usually look the best) in the fall. Cool season turfgrasses have been in existence for thousands of years, and have adapted to our climate pretty well. Most turfgrasses can endure some degree of drought, some better than others. If certain species couldn’t handle drought stress, they probably wouldn’t survive in a turf stand, and would be crowed out by those that can, right?
Believe it or not, turfgrass populations are very dynamic, and the predominant species or even cultivar of a single species changes throughout the year; just ask a golf course superintendent about annual bluegrass and creeping bentgrass. In most cases, turf managers can’t do too much to control which species (or cultivars) survive better than others. However, we can incorporate those varieties that are best adapted to the situation at hand – by overseeding. So, select the right blends or mixes for your situation as some lawns should have two or even three different species of turfgrasses, depending on soil conditions, shade, moisture, etc.
Now let's examine what caused a particular turf decline or loss. Understand that stress to turf (such as drought, intense heat, compaction, traffic, etc.) will certainly predispose turf to more problems. In 2016, drought has led to turf decline or loss both directly and indirectly. Drought stressed turf which is then subjected to insects, disease, and even fertilizer applications can definitely put turf “over the edge”.
As of September 14th, 2016, I have confirmed cases of each of the following pests in lawns this fall: billbugs, chinch bugs, grubs, and sod webworms. More often than not, turf insects are present in drought stressed lawns.
Billbug adults usually overwinter in leaf litter and thatch, become active from late April through mid-May when temperatures exceed 65°F, and are frequently noticed walking across driveways and sidewalks. Photo: Nancy Bosold
Healthy turf can withstand a certain amount of insect and disease pressure, but under stress, that significantly drops. Understand the differences between each of the turf pests, and how to correct them. For example, does the turf roll back like a carpet? Can you pull up dead grass stems, but the roots do not come up with it? Are there small moths flying around?
Billbug frass at base of damaged stem. Photo: Nancy Bosold
In many cases, an insecticide application is warranted, but aeration and overseeding is also necessary. Maybe you should think about adding a surface feeder insecticide treatment next year, especially if turf is being subjected to prolonged periods without rain. The turf (and homeowner) will appreciate your due-diligence.