not sure about plants but last year we were at the vets like every 3 weeks to keep ontop of flea treatment and sprays for the house { they were bad last year here} until I started feeding them these pills with there food brewers yeast with garlic I swear hey were like majic pills for us , it was like 2 pills fore every 10lbs so there was alot for my bigger dogs but the fleas were gone , and they are outside alot in the summer I leave doors open and they are in and out. No fleas since havent even seen any. dont know if this works for others but its worth looking into imo. Hopefully I wont have to use any of those pesticides and poisons on them this year I really didnt like having to use advantage that much but had to do something.