Grubs
Chances are if your lawn feels spongy, is brown, and is being picked apart by crows, raccoons, skunks or any other pests, your lawn is being victimized by Grubs. Give us a call so we can provide information to help you manage this problem!
What are they?
Grubs are the larvae of certain beetles, like June beetles and European Chafers. Grubs are one of the hardest lawn pests to deal with.
Grubs are white or yellowish and have fleshy, wrinkled, C-shaped bodies with tan or brown heads and six spiny legs. They are quite small when they hatch, but when fully grown are from 2 to 4 cm (.75 to 1.5 inches) depending on the species.
The most common white grubs infesting turf in Canada are those of the native June beetle or June bug. Two smaller exotic species, the European Chafer and the Japanese beetle, have been accidentally introduced into Canada and are found mainly in the Niagara peninsula. The European Chafer, though, has recently migrated further north and east, and is responsible for much of the lawn damage in recent years.
How do I know if I have a problem?
Affected areas will feel soft and spongy to walk on, and turf in these spots can be lifted up with ease. Carefully fold back the turf and note the number of grubs exposed. Eight to 10 grubs per square foot can damage a lawn.
Damage is most severe in the spring and fall when moisture levels in the soil are high. During drier periods, the eggs may be killed and surviving larvae can be found deeper in the soil. Extremely dry summers destroy many eggs and newly hatched grubs. Mature grubs can be found near the surface in late summer and early fall.
Often, skunks and other small mammals will pull back the turf to feed on grubs in the spring or fall. This secondary damage to your lawn, are signs of a grub infestation. If you have any of these natural predators digging at your grass, check for white grubs. Many people notice these indicators first.
How can I manage grubs?
Lawn care
The best thing you can do is to make sure your lawn is healthy before any problems happen. If you can, dig or till your land one year before you seed it or lay sod. Remove old plants and weeds, then rake/de-thatch your lawn or cultivate the soil thoroughly to expose any grubs to their predators and the weather.
Healthy, vigorously growing lawns can tolerate more grub feeding than stressed lawns, because damage to one root is made up for by others. Remove excessive thatch, and aerate compacted soil areas to ensure proper drainage. A soil aerator with spikes or spiked sandals can also help kill some of the grubs.
Beetles prefer to lay eggs in closely cropped lawns, so raise your summer mowing height to 6 to 8 cm (2.5 to 3 inches). Leave lawn clippings after mowing, because their slow release of nitrogen encourages micro-organisms to break down the thatch. Use fertilizer with high potassium and enough nitrogen.
If you notice grubs during the warm, dry periods of the growing season, water and fertilize your lawn to strengthen it and make up for the root feeding damage. Apply a top dressing of sand and manure and overseed with grass. Deep, infrequent watering encourages deep-rooted, drought-tolerant lawns. Water no more than once a week, and water until at least 2 cm (1 inch) of water collects in a container placed on your lawn or for about one hour.