Cannabis Seeds FAQ - How Big Will My Plant Get?
If you have a small space and lots of plants that will stretch, then you will want to restrict the amount of vegetative time you allow them. Conversely, if you have a single plant in a large space you will want it to grow large to fill the space.
Very generally speaking most strains should be given 6 weeks of grow time from seed in order to allow time for the hormonal change from a seedling into an adolescent plant. This is especially true if you are looking to take cuttings from the plant.
So now I know how big my plant will get, do the genetics have anything to do?
It is possible to flower plants directly into 12/12 -the result depends primarily on the genetics of the strain.
If an Indica dominant variety, you may end up with a very small single cola. A Sativa dominant plant will tend to grow larger as they rely more on overall body-mass before flowering.
Normally we find Hybrid Sativa dominant plants can stretch up to three times the size from when you change your lights.
You might also find our FAQ Submission What Are The Differences Between Indica And Sativa? useful