Well, I think that mescaline is produced after the first year, but nothing too signifient. From the time you plant the seed to harvest time is usually 3 years, at the VERY least, but usually 5 or 6 years. San pedro grows much faster if you are looking for just a mescaline containing cactus. It is always good to grow a San Pedro also, but I love growing peyote, there is almost a love between me and my peyote. It is like my little children, and I know when I injest it, all those years of waiting will be well worth it. My peyote is going on 1 year and only about 1.5cm wide. Usually harvest is around 6 or 7cms.