*Commercial bleach contains about 5% sodium hypochlorite, and thus may be used at a concentration of 10-20%, which is equivalent to 0.5-1.0% sodium hypochlorite.
Orchid seeds are very small and contain little to no food reserves. A single seed capsule may contain 1,500 to 3,000,000 seeds. Sowing the seed in vitro makes it possible to germinate immature seed (green pods). It is much easier to sterilize green capsules than individual seeds after the capsule has split open. Lucke (1971) indicated that orchid seed can be sterilized when the capsule is about two-thirds ripe. Listed below are the estimated normal ripening times of capsules for various orchid species.