The best time to apply Scotts GrubEx1 is between spring and early summer when the insects have burrowed into the lawn to lay eggs. GrubEx is designed to avoid turf damage by killing grubs and Japanese beetles as they emerge from the larvae.
One application lasts up to four months, an entire summer season, according to Scotts. Along with grass, GrubEx can also be used on flowers, shrubs, trees and ground covers. GrubEx1 has an online customer rating on the Scotts website of 4.6 stars out of 5 and a recommendation rating of 93 percent. Advantages of the product, according to customers, include its effectiveness, value and easy-to-follow instructions.