Hi Jim, I also reuse my potting mixes, and also grow Oxalis. The way i stop having Oxalis through every pot, is " to use my old Oxalis potting mix, only to repot Oxalis into". I have one or two Oxalis and it takes a wee while to pot them all. We have just moved house and The photo link, is half my collection. Also one of some plants in flower. http://public.fotki.com/savagegardenz/oxalis-1/… http://public.fotki.com/savagegardenz/oxalis-1/… They can become weeds, but not all do.But they are such a joy when they are all in flower. Happy growing from, Kiyel in New Zealand.