I do have some grubs (I have seen them). I also have noticed "holes" in some of my plants. I guess some sort of insect is doing that. I would like "cheaper" methods if possible.

To get immediate results mix about 1 oz of dish soap and a gallon of water. Spray on your plants using a pump spray. Don't use the antibacterial. The soap is bio-degradable and will kill the live bugs and will not harm you or your plants. Once it dries it does not continue to kill bugs, it is a kill on contact. If you have bugs the next day you can spray again.