Racefan
Well-Known Member
Every person I've ever heard who tried to use rain water run off for watering their plants (including myself) ended up with plants with root rot or what's called "dampening off". 6 or 7 others besides myself actually. Think about it...the roof is a nasty enviroment with pollens and anything else blowing in the wind and animal and insect shit on it as well as oils from the shingles and seam sealants.