September 5, 2020
Bare patches in the lawn? Chinch bugs are having a heyday this year. White grubs are not quite as bad as the past few years. Let’s take a closer look at both.
Chinch bugs are tiny greyish brown insects that are almost impossible to see. They spend the winter under the shelter of shrubs and low growing plants and emerge in late spring to deposit eggs. The eggs quickly hatch and the nymphs become adults in early summer, around mid-July.
By the end of July, damage is evidenced by small dead patches. If damage is severe, the spots run together to form large dead patches.
Chinch bugs love hot dry weather. The hotter and sunnier the better. July 2020 was a dream-come-true for these insects that feed on the crowns and stems of healthy grass.
In Ontario there is no magic insecticide available for chinch bugs, but gardeners who maintain good lawn care practices will find that Chinch bugs rarely cause damage. Water deep, but don’t water often. Fertilize faithfully. Aerate to avoid soil compaction.
Chinch bugs do not like cold water. When the weather becomes hot and dry, drag out the water hose and put the sprinkler on for a few minutes each day. The Chinch bugs will soon scurry off for greener pastures. Chinch bugs do not like shady areas of the lawn and chinch bugs will not bother a lawn that is well-watered and well fed.
To test your lawn for Chinch bugs, get a large tin can and remove both the bottom and top. Force the tube partway into the soil at the edge of a damaged area. Fill the can with water and the insects will float to the top.
Grubs are the larval stage of beetles, the most abundant being Japanese Beetles. Grubs are greyish white and shaped like a C. Adult Japanese Beetles feed on foliage in summer and lay eggs till the middle of August. Eggs hatch in a few weeks and the tiny larvae begin feeding on the roots of grass in September. Damage is minimal in September because grubs are small.
At the end of September as weather becomes cooler, grubs crawl deep into the soil where they will spend their winter. In spring when the soil warms up, grubs are hungry and will create considerable damage. Dead patches appear, and severely damaged grass can be picked up like a wig. Grubs pupate in June and the cycle repeats itself.
Control grubs by applying beneficial nematodes, which are naturally occurring tiny organisms that feed on grubs. The best time to apply is early fall when grubs are young. For nematodes to travel in search of food, make sure your soil is damp.
Grubs are somewhat cyclical, and it is difficult to predict when they are abundant. Grubs like the insulating protection of a good layer of snow in winter, which could explain why Spring of 2020 saw less grubs than in previous years.
Recent rains have been favourable for lawns, and turf is looking as good as ever. But for those who have weak or damaged turf, sow grass seed in the fall. September’s cooler nights, frequent rains and morning dew will guarantee success in sowing seed.
To sow grass or rejuvenate weak lawns, rake out excess debris and add a thin layer of fine topsoil. Broadcast the seed at the rate of 1 pound of seed covering 250 sq feet. Lightly rake it again and within a few weeks you will see grass beginning to grow.
Choose the right seed blend to suit your needs. For shaded areas, choose a blend that contains Creeping Red Fescue and Poa. For instant gratification, choose a blend that contains a high percentage of fast sprouting Perennial Ryegrass. For a fine textured, deep green lawn, look for more Kentucky Bluegrass.
As your seed begins to grow, do not worry if it does not grow evenly dense. And do not fret over a few weeds, because most weeds are annuals that will die off with the winter frost.
Finally, once your grass has sprouted and you have cut it two or three times, probably about 6 weeks after sowing, go ahead and apply fall fertilizer. The extra food will cause grass to thicken up and will give a head start for spring growth.