I bought this Larch about a week ago and I would like to give it a preventive spray of insecticide soup. I was told I could make my own with dish soap, but didn't get the specifics. so my question is, exactly what kind of soap. I have "Ultra Palmolive, fresh green apple", phosphate free. Exactly how much soap per quart or gallon. Are we talking just a drop or two. I was told this would work on Spider Mites. I had a Shimpy w/ mites, and that's when I was told I could make my own soap, but bought some instead because I didn't want to take any chances. The stuff goes quick if I spray all trees every 10 days, so I looking for something more economical. OK I'm rambling.