While I don't think used soil will cause a sex change or influence hermi development, I would not suggest using old soil. That soil will have little to no natural nutrients left and that does your girls no good.

Best idea is just get some new soil.
oSecretGardeno Reviewed by oSecretGardeno on . Used Soil Determine Sex or Alter Sex? Maybe dumb questions but here they go Planted 14 seeds, 13 grew and now at 12 weeks 1st off plants sexed with 24hr light... i never turned lights out. is it possible to use the soil from the now dead male plants? they still have roots in them... if i use this soil for my plant that are female, will this alter the females or make them hermies or will everything be ok? thanks all:thumbsup: Rating: 5