On 25 Jul 05 at 18:36, Kathy Stokmanis wrote: > On another list it was recommended to add hydrogen peroxide > when watering plants (Hoyas, in this instance) in order to > directly supply oxygen to the roots and increase aeration. > Being an uninformed neophyte, I don't know if this is > plausible for bulbs, or even for hoyas, or is one of those > myths perpetuated by mysterious internet forces. Any comments > or jeers? As a chemist, it sounds to me like a theory devised by someone who doesn't understand what's going on. It's not *oxygen* that plants need at their roots, but *air* *exchange*. Of course, that subsumes a good supply of oxygen, but I'm quite certain that oxygen is hardly the sole issue. If your plants are suffering because of lack of oxygen at the roots (ooops, what did I just say?), the solution is to use a potting mix with better aeration. Hydrogen peroxide has one valuable horticultural use: sterilizing seed before sowing. There are some seed-borne diseases that can be controlled that way. -- Rodger Whitlock Victoria, British Columbia, Canada Maritime Zone 8, a cool Mediterranean climate on beautiful Vancouver Island