Have you been looking for a natural way to kill grubs in your lawn? An organic grub killer? Are you concerned that your lawn might be at risk for Grub Damage? The good news is that you can control grubs without using chemicals! Read on for some tips.
The first step in Natural Grub Prevention is to water your lawn properly. How does watering affect grubs? First let's take a look at what a grub is and it's lifecycle.
The image above shows how a Japanese Beetle comes out of the ground in late June, feeds on plants through the summer, and then lays eggs that turn into grubs in the fall. Have you ever watched Japanese Beetles closely in the summer? You'll often seem them stacked on top of each other, hard at work making some eggs.
In order for the Japanese Beetle Eggs to turn into grubs, they need moisture. So, if you water your lawn every day during the summer, you're giving the grub eggs just what they need to survive! So if you don't water your lawn, it will probably go dormant but it will be less likely to have grub damage.
The best way I've found to prevent grubs organically without using any chemicals or products at all is to plant Turf Type Tall Fescue (Midwest) that has a really deep root system and can get by with one deep watering every 7 days even in periods of hot dry weather. The Turf Type Tall Fescue (like found in our Tuff Turf Grass Seed) is also less likely to show signs of grub damage because its roots are so extensive that a little feeding by grubs doesn't usually cause a lot of problems. Shallow rooted grasses like creeping bentgrass show a lot of damage from grubs because there just aren't a lot of roots to spare.
What if you don't have a Tall Fescue Lawn and you're concerned that you might have some grub problems? The best time to kill grubs in a lawn without chemicals is in the late summer or early fall when the new grubs are really small. We've found that Beneficial Nematodes will eliminate 50-75% of the grubs in your lawn and that is usually enough to minimize the damage. What? You want to kill all the grubs? Well that just isn't necessary or even possible. A healthy lawn can withstand up to 6 grubs per square foot. If you have an average american lawn (8,000 square feet or 1/5th of an acre) your lawn can withstand 48,000 grubs before showing signs of damage. It still might be a good idea to do whatever you can to reduce the populations though and that's where our All Natural Grub Killer will come in handy.
Beneficial Nematodes are Microscopic Worms that occur naturally in all soils. Like people, there are good nematodes and bad nematodes. The bad nematodes it plant roots, and the good nematodes attach themselves to grub larvae in the soil and suck the life out of them. Most soils are lacking in good nematodes so it helps to apply a few extra early each fall to reduce the number of grubs in your lawn.
Beneficial Nematodes for Grub Control are easy to apply. A hose end sprayer is probably the preferred method of application. The nematodes come in a powder and you add the powder to some water in your hose end sprayer, shake it up, and apply it over the area you'd like to treat until you've used up the right amount of nematodes. Nematodes can die in the sunlight so it helps to use a lot of water when you're applying them and water them into the soil. If you make the application in the evening that gives the nematodes all night to work their way into the soil before the sun comes up the next day.
Application rates for nematodes vary widely. Some claim control with very low rates and others recommend very high rates. One pack of 50 million of our nematodes will treat between 2500 and 5000 square feet. If you know you have a lot of grubs and you're concerned about the damage, you'll want to use the pack to cover 2500 square feet. If you're applying it just as a preventative and haven't had grub problems in the past, one pack of 50 million will probably cover 5000 square feet just fine.
I recommend Milky Spore to reduce the number of Japanese Beetles you have in your yard. Milky Spore is just spores of something called "milky disease" which infects Japanese Beetle larvae (one type of grub). The problem with Milky Spore is that it doesn't work against European Chafer Grubs, Masked Chafer Grubs, and other grubs that can do more damage to your lawn than a Japanese Beetle Grub can do. So, if you're trying to fight Japanese Beetles, Milky Spore is great because once it gets established, it can fight grubs for up to ten years! But, if you're trying to protect your lawn from grubs, I recommend using the Beneficial Nematodes every late summer (September is Great).