So glad you are so conscientious about not overfeeding your plants. I have heard good things about Peter's fertilizer but have never used it myself and so cannot give you any personal recommendation other than to read and follow the directions of the package for dosage and the directions on the Ortho sprayer. You can look those up online if you have lost the instructions. Be sure to underfeed rather than overfeed with a liquid plant food and I always avoid fertilizing with liquid plant food on hot days or when the sun is shining on the plants. This will help to avoid fertilizer burn on tender plants. Keep growing, Marianne Binetti