If you let the frost kill the plant, you will 100% with out a doubt, destroy the yield. If the plant dies while still in the ground it will start molding in as little as an hour, which is indecipherable just by looking at the flowers(which results in lost crop).
One thing that should be understood when growing plants like this, is, the chemical THC (delta 8THC) is not present in the plant so we can make goo balls from it or smoke bongs..
the THC is a biological defense mechanism against interstitial ice crystals forming with in the plant cells in colder temperatures, before the plant has a chance to become pollinated and come back next season.. thus, it is acting as an anti-freeze, because the sexual maturation of the female plant(pollen receptive phase) happens in early to late fall..
So... 2 or 3 good frosts is crucial to ramp production of THC in the flowers(not to be confused with potency, potency is correlated to the conversion of the THC molecule from delta 8 to delta 9 thc..[read further down]), yet you must not let the frost occur in the low 20's which can cause plant death..and again you wont get shit..so watch the weather..
the rule of thumb for harvest is at least one good frost..which triggers the pistilation (white hairs) to subdue and turn to orange and the trichomes should turn from clear or milky to amber.
when the pistilation subdues it marks the end of the ovaries reception to pollen and the changing of the trich color denotes the transformation from delta 8 thc to delta 9 thc(which is the more potent of the 2 phases of the chemical) this usually means the plant has run its life cycle for the season and will start to go south...get that thing hangin by this time... also another crucial notion to adhere to is..when the plant is cut back IT MUST BE 100 % DRY!!! or it will mold and again you wont have shyte!
as stated above, the potency of your harvest is directly proportional to the length of cure..ever buy a bag and you get all excited to get stoned yet nothing happens???..that herb was not cured properly, it was hacked off the bush and dried quick to hit the market..
allowing your plant to dry over a period NO LESS than 3 weeks in a dry, cool, sunless environment with good air exchange will enurse the thorough conversion to the delta9 thc..
and remember.. when the weathers hot and sticky..thats no time for sticky icky
when the frost is on the gourd thats the time to cut and hoard..
10/09/2009.. good luck