Weevils and White Grubs
In the northern parts of the region Annual Bluegrass Weevils are just reaching their larval stage while the southern areas should have already incurred the worst of the primary generation. The damage should not have been too severe as the first stage occurred during the earlier part of June when the rainfall was sufficient and soil temperatures were not yet so high, making the pest stress manageable. Another generation of adults will be along anytime now, monitor closely for best management. The second influx usually lags about 2 weeks behind peak damage which may put many of us on course for this week. Keep a close eye out and talk to your arborist now in order to get optimal control of this problem. Now may also be a good time to consult your arborist about white grub control if it is not already a part of your program. Watch out for chinchbug and billbug activity which will increase soon as the temperatures continue to rise.
This is a topic that has been covered on this blog and elsewhere before, but it is always a good one to reiterate and rehash. Summer has been in full swing for a while and mowing has been an necessity for almost as long. The basic, and most energy efficient, convention is to recycle your clippings back to the turf as often as possible. This way the clippings break down and the nutrients contained therein are returned to the soil, recycling them within the turf system. Turfgrass species absorb nutrients from the soil, some of which become incorporated into plant tissue, when the plants senesce or grass is mowed microorganisms go to work, breaking down the tissue into vital nutrients which go back into the soil for reuse by other plants. Keeping nutrients in this closed loop can help guard turfgrass from environmental stress and reduce the need for fertilizer application.
Take care not to allow large amounts of clippings to sit in place on your property, the high levels of nutrients that we would like to return to the soil can have negative effects on water quality if allowed to be carried with runoff and may cause clogged drainpipes if moved with stormwater. Fall leaves, granular fertilizers and grass clippings have large amounts of phosphorus which can leach out and become readily mobile when allowed to accumulate and stand on impervious surfaces. Without proper attention yard waste can be swept into water bodies adding to nutrient loading, algal blooms and decrease of water quality.
If used appropriately, over long periods of time, clippings help conserve and build organic matter within your turf system. The organic matter layer acts as a nutrient reserve and aids in the capacity of your lawn to retain water. In the long run, this will allow for a somewhat more self-sustaining system which is energy efficient, a sink for stormwater and resistant to erosion. And, contrary to popular belief, clippings do not contribute to thatch production. Consult with your arborist for more information on using clippings and yard waste, pest control and proper lawn turf maintenance and management.