Yesterday I attended a workshop at O.S.U. in Stillwater on Winterkill of Bermudagrass and Spring Dead Spot. Both are big issues now on bermudagrass lawns, so the turfgrass department gave us the latest information on both. Part of the challenges of growing bermudagrass was evident while we were there, wearing jackets in mid-May due to the temperatures in the 40’s. Bermudgrass just won’t do much until temperatures get into the 80’s and 90’s consistently, with nighttime temperatures at least in the 60’s. That’s not been the case this spring, which is the reason I’ve only had to mow my bermuda lawn once this year so far.
Although it was a long, cold winter, Dr. Martin from O.S.U. stated that while we’ve had some winterkill, it’s fairly spotty. The bermudagrass is just having a hard time getting going with the cool weather, and in some cases the lack of adequate soil moisture. They did visit about the fact that some varieties of bermudagrass are more susceptible to winterkill than others, hence the fact that some lawns are affected and some look just fine. There are many varieties of bermudagrass, and many genetic differences within certain varieties, such as U3 Common. So just as people do not all look and perform alike due to genetics, the same is true of grass.
Spring Dead Spot is a fungus disease, again more common on certain varieties of bermudagrass. That’s why some lawns will have it, and others will not. While soil fertility, weather, drainage, and turf age are all factors, genetics is the major factor in disease incidence. One study that O.S.U. did recently showed that ending nitrogen fertilization on bermudagrass by mid-September decreased the severity of the disease. That’s exactly what we do at LawnAmerica, with our final “fall fertilizer” for bermudagrass applied in August into early September. So while we can make a lawn dark green and lush with fertilization in late September and early October, that’s not what we want to prevent Spring Dead Spot from taking over a lawn. Fertilizing with nitrogen too late in the growing season also hurts the root system, which makes the grass more prone to winterkill. So we try to run the turf a little on the lean side as we go into fall as far as nitrogen and color is concerned.
Even if we do all the right things though, Spring Dead Spot can still come in and be a factor. In severe cases, O.S.U. recommends two fungicide treatments in fall, when the Test showing influence of fertility on Spring Dead Spotfungus is active, to prevent the disease from being severe the following spring. We can provide that at LawnAmerica with our Spring Dead Spot Fungicide Treatment, and it does seem to show some decent success. It’s not perfect, but one can expect to see fewer dead spots the following spring, and they will fill in faster with healthy bermudagrass. We apply one treatment in early September, and followup with another 30 days later. The fungicide does need to be watered into the soil for best results after treatment. Fungicides are not cheap, so our fee is 2.1X your normal lawn treatment cost to cover both treatments.