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  • Writer's pictureRandy Lopez

The Best Time To Treat for Grubs In Your Lawn

Updated: Feb 22, 2020

There are a lot of reasons why certain patches of grass don’t grow very well but one of the most common in Saint Charles lawns is grubs (otherwise known as Japanese Beetles). These harmful invaders lay their eggs in the dirt under your grass in the summer. Those eggs grow up and feed in the fall and spring. This cycle of feeding can be extremely harmful to the grass in your lawn. In this blog post, we’ll discuss the best time to treat for Japanese Beetles/grubs in your lawn. If you don’t want to do the treatment yourself, let your local Saint Charles lawn care specialists (that’s us) help you by

The grubs are closest to the top of the soil in the spring and fall. Any other time of year would be difficult/impossible to reach them and killing the adults doesn’t stop the process after they’ve laid the eggs. While it’s possible to treat the grubs in the spring time (April to June), that is not the ideal time to do it. In the spring, the grubs had an entire fall and winter to strengthen up and become larger so they are much more difficult to kill. In the late summer to fall, the grubs are just barely starting to grow and they are much closer to the soil surface so they are easier to kill. 

It’s important to note that just because you have adult Japanese Beetles flying around, doesn’t necessarily mean you have grubs in your grass. Adult beetles will fly far distances to munch on tasty bushes and leaves. If you take a small flat shovel and dig just under and parallel to the grass (like in picture below), you should be able to see the grubs in the spring and fall. The grass in these areas will show bad growth and patchiness that won’t be apparent in other areas. 

How To Treat Grubs in Saint Charles Lawns

Here at Lopez Lawn & Landscapes, we aim for the two weeks after the 4th of July as a great time to apply insecticides for grubs. By that time, the grubs have had enough time to start feeding on the roots and be very close to the soil surface but are still small and easy to kill. The best treatment for these grubs is a chemical called "Imidacloprid". It is safe for mammals and most fish so it has a small impact on the local ecosystem but does kill the grubs damaging the grass. We use a granular treatment that only requires one treatment per year until they are completely eradicated. It may or may not effect some honeybees but if applied to only grass areas with possible grub damage, the impact on these important creatures will be minimal.

We also use Organic Milky Spore granules. Early Fall when they're in the hatching stage of their cycle. We apply organic milky spore granules. Japanese beetle grub eat the spores during their normal feeding patterns, then the spores reproduce inside the grub eventually killing grub within 7-21 days. As the grub decomposes, it releases millions of new spores and these multiply and kill other grubs.

If you’re looking for lawn help in the Saint Charles area, look no further than Lopez Lawn & Landscapes. We have the experience and knowledge to help fix any lawn issues. Give us a call at our office 636-579-3471 or and we’ll get in contact with you. Getting that golf course quality grass shouldn’t be impossible, we can help make it happen. 

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