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Beneficial nematodes kill the grubs that turn into Japanese beetles. Ideally, apply them in spring before the beetles emerge. The second half of this 1-2 prevention punch is Milky Spore, which also kills grubs. It takes a year or so to get established in your soil, but it keeps working for 10 years or more.

Hand Pick: Unfortunately, the most effective way of getting rid of Japanese beetles is to hand pick them. It's time consuming, but it works, especially if you are diligent. When you pick them off, put them in a solution of 1 tablespoon of liquid dishwashing detergent and water, which will cause them to drown.

Water every 2-3 days for the first month. After that, a good watering once a week should be sufficient, but monitor it often as windy days can dry out soil quickly. If the tree is fall planted, water once a week when no rain or snow cover is provided.

You can spray the plants with Japanese beetle killer, found in most retailers and online. Sevin dust can also work, but it might kill beneficial insects along with the Japanese beetles. Some ingredients to look for when purchasing an insecticide are carbaryl, acephate, and permethrin.