lol i always count from when they pop, as its like a baby, (you dont count how long the embryo was made for,) you start counting when its born, keep a peice of paper and name your plants, put the names on the paper, and make a tally chart, everyday just add another tick to each one, also take down birthdays, my m8s plant has been alive for a whole year, and we celebrated her birthday with a nice big blunt just the other day, its in the final stages of flowering now, just remember plants are like people, seed-->egg n sperm, germinating seed-->embryo, seedling-->baby, then adolescent, adult, and eventually past its sell by date.. count it however you will, it hardly matters