Susan, I assume you are collecting sales tax for Ohio when you do your maintenance work. So why wouldn't you collect it on the plants, also.
(For those of you not in Ohio, up until 20 years ago landscapers only collected sales tax on materials. The state needed more revenue and started applying sales tax to certain services, among them landscaping and auto repair.)
Starry Night Lighting
"This little light of mine, I'm gonna let it shine."