Dear Stoner: How long does it take for pot to go to four nanograms in the bloodstream so a person can drive? Does it happen overnight? What if they are smoking at midnight and really stoned? Also, I know I can grow my six plants with three flowering. Can that be sold to a dispensary?
Dear Paranoid: Your questions are uber-broad. There are a number of factors that could determine how long it takes for someone to get to four nanograms after getting stoned — but even if we had more details, we still wouldn't have much of an answer. Alcohol degrades in the bloodstream at a pretty constant rate regardless of the individual, to the point where someone can roughly calculate when they are at or below the legal limit to drive. Generally speaking, that's about one drink per hour. Go over that, and a simple chart will tell you how long you should wait until you drive.
Marijuana isn't like that. Metabolizing cannabis works at different speeds for different people. And because tolerances build up, the active THC amount needed to get a once-a-month toker high is going to be much lower than what it would be to get me stoned. Generally speaking, though, if you are a non-heavy user and you smoke a couple of bowls or a joint for the first time in a week on a Friday night, you should be fine by mid-morning on Saturday. Your levels usually peak about an hour after toking — into double digits for some — and then dip back down to single digits within a few hours. Edibles peak more gradually than inhaled pot.
But if you're a moderate-to-heavy user, you could wake up well above the limit and even test above it far into the next day. Back in April 2011, I had my blood tested after a night's sleep and fifteen hours of abstaining, and still came up with 13.5 nanograms of active THC in my bloodstream. Your best bet is to be smart, and if you're impaired (on pot or anything), don't get behind the wheel. Fortunately, unlike drunks, most of the get-way-too-high people we know admit it when they are too high to drive/bike/walk/eat like an adult.
As for your plant question, we answered a similar one a few weeks back. The long-short of it is that there's no precedent for co-operative grows, but the Colorado Constitution does allow adults to assist other adults in growing their cannabis. As for your surplus: No, you can't sell it to a dispensary — or anyone else, for that matter. You'd need to be a licensed wholesale grower to put your buds up for sale in a recreational pot shop. You can give it away to friends who are 21 and up one ounce at a time, however. And if you don't have friends, we'll gladly take donations.