X3
Don't just leave this until winter either,I try to get every client on lawn & garden maintenance,you will find that those who accept do not bump you through winter and stay consistent(none of mine go beyond 3 weeks).
The difference these customers can make to your bottom line is quite substantial. I was running the numbers the other day comparing regular lawns only with regular lawns/gardens(not including clean-ups/one offs) and the difference in return for hours worked was pretty astounding.