- Nick Ahrens
Prior to North America being colonized during the early part of the 1700’s, the landscape consisted of forests and prairies. The traditional lawn as we know it did not exist. The word lawn comes from the English word launde, which means a “glade or opening in the woods”. These openings would have consisted of native grasses like buffalo and bluestem grass. The colonists soon realized these types of North American grasses were tough and not adequate to feed livestock so they started bringing over European species. These are the ones you’ll recognize in your lawns today like Kentucky bluegrass. After world war II planned suburbs became increasingly popular and along with them came the lawn. These lush green, weekly cut lawns are an unnatural result of the colonists problem solving abilities.
Deviating from and manipulating nature always comes with a cost. Our lawns today mainly consist of Kentucky Blue, Perennial Rye and Fine Fescue grasses. These roots typically grow from 6 to 24 inches deep in the soil. The native plants of north America have root systems that can be found growing up to 16 feet deep in the soil. It is for this reason native species are much better at tolerating things like drought, insects and disease. And there in lies the cost. The lawns we know today need a lot of supplemental watering, fertilizing and cultural practices to make them look good.
One of the problems that comes along with owning a lawn is Grubs. White grubs are the most common and will chew off the grass roots below the soil surface starving the grass of moisture and nutrients. They can range from 3/8” to 2 inches long, appear white and C-shaped. Grubs are actually the immature larval form of Japanese beetles, June beetles and Masked Chafers. These beetles and chafers lay eggs in the soil during June. These eggs turn into the larval grub stage which then feed on the grass roots. The damage becomes evident during August and September.
As temperatures cool in the fall these grubs move downward in the soil where they lay dormant for the winter. As temperatures rise in the spring they move back up and begin refeeding. They mature in May and move deeper into the soil to transform into pupae. The adult beetles emerge from the ground from June through July to complete the one-year life cycle.
The main symptom is irregular, yellow patches which then die off. These patches can easily be pulled up like a carpet. The presence of birds, skunks and racoons digging and feeding in your lawn may also indicate you have a grub problem. Irrigation systems can mask these symptoms and in these cases the turf will feel spongy when you walk on them.
There are 2 ways of dealing with grubs. The first and most effective way is to apply a grub preventative. This application is applied during June or July to control the pest while its younger and more susceptible to control. This product is less expensive and prevents costly repairs to turf from the damage grubs can do. The second and less effective way is to apply a grub curative control. This application is applied during August after the eggs have hatched and grubs are present. With this product timing is very important because the chemical has a short lasting residual. This application is more expensive due to the cost of the product and also the repair cost for the lawn. It's also more critical this product gets watered in after application because of its short residual nature. It is for the above reasons we recommend having a grub preventative applied to all of your turf areas during the month of June or July each year.