People like to speak about autoflowering veg time in terms of days & weeks rather than the plants development.
Whilst there are a few strains that won't fit the following, it is a good rule of thumb for around 90+% of autos.
Autos tend to start flowering as the 4th (true) node is forming (best to top just before that point!), not at x amount of days... plants can't count days but they know where they are with regards to their development
Bookmarks