the rain does not wash away trichomes!!!!!....thats just stupid....the rain will cause bud rot depending on the strain.the only thing you need to do is after it rains go out to your plants and shake them off.dont shake the crap out of them just enought to get water off.do it every rain fall and if its gonna rain for few days straight go out there everyday and shake them off....if the rain is coming and you have ways to put a tarp over them do that so the rain doesnt get to the plants..