Critters digging for grubs could cause lawn holes
amps up fall color, anthocyanin, is produced only by some tree and shrub species. The amount they produce varies by species and depends both on that year’sweather and the circumstances in which 12 per square foot of lawn. the tree is growing. Adult beetles generally
“A sugar maple growing Q: Someofmy lawn lay their eggs in full-sun among other trees in the was dug up last night. lawns that aremoist in woods will produce more There are a bunch of July. If your lawn has been anthocyanin at the top of small holes in about a irrigated and is surthe tree, where leaves are 20-foot-by-20-foot secrounded by dry lawns, and in full sunlight,” Hedborn tion ofmy lawn— it you see adult beetles flying said. “It will only have red looks almost like someabout, then there is a greatand orange high up in the one ran a rototiller in the er chance of your having sun. The same species of area. Aneighbor thought grub problems later in the year.treegrowingbyitself Imight have a grub probmight be red and orange all lem. What can I do to Monitor lawns starting over, because the sun can prevent further damage in mid-August, continuing reach more of the leaves.” tomy lawn? into September, for signs of
You can’t control the — Benjamin Gleason, grubs. Damage fromthe weather, but you can help Barrington grubs can continue into the trees and shrubs in A: Most likely you have October. As temperatures your yard develop good fall grubs in your lawn, and the cool in the fall, the grubs color by caring for them holes you are seeing are tunnel down to overwinter. attentively all year long. “If being dug by raccoons or Make sure that grubs youwater your trees when skunks looking for the are the problem before theweather is dry in sumgrubs. I have been seeing applying any controls. I mer, theywon’t suffer from several lawns with this have seen many lawns drought stress thatwould damage the last couple of with dead areas that apmake them enter dorweeks. It is a relatively pear to be caused by a mancy early,” Hedborn common problem this time disease called Pythium said. of year. Late summer and blight, not grubs, this fall.
Newly planted trees early fall is the time that The damage due to needwatering every few grub damage is most likely Pythium blightwas showdays, and even mature to showup in lawns. ing up severalweeks ago. trees needwatering when Grubs are the larval Lawns showing damage it doesn’t rain for several stage of beetles. The grubs from grubsmay be treated weeks. If you care for your feed on the roots of graswith an insecticide, though trees, your payoffmay be a ses, so there can also be it is starting to get late to be more beautiful autumn. wilting and browning of worthwhile. I prefer not to irregular-shaped areas in apply the preventative lawns infested with grubs. grub controls recomCarefully pull back the sod mended in early summer, in any suspect areas and as grubs generally are not a look for the white, Cproblem each year, and I shaped grubs just under believe in minimizing the the soil. Turf damage is amount of pesticides used likely when grub populato maintain landscapes. tions reach more than 10 to Be sure to choose the right product for controlling them at this time of year— products that are sold to prevent grubs will not be effective in the fall, as they are slowtomove in the soil. Read and followall label instructions. Grubs should be listed on the label as one of the insects being controlled.
When treating your lawn after grub damage is observed, treat in and around the affected areas, since the grubs can also be a problem in adjacent areas. The insecticides such as trichlorfon used for controlling grubs in late seasonwork by contact, so it is important to promptly water in the product for it to beginworking. Irrigation is essential for these chemicals to be effective.
Add grass seed as needed to repair the damage. Be sure to keep the new grass seed moist until it germinates in a couple of weeks. Even if the grubs are all killed, the animals may return and continue searching for them.
For more plant advice, contact the Plant Information Service at the Chicago Botanic Garden at plantinfo@chicagobotanic .org. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.