Topping

My plants are a month old and being a newbie IDE like to know how old they have to be before I can top?

You can top after a few nodes say 4 set of leaves.

Don't go by age for the first topping, go by root development. You can guess at that by counting the nodes on the plant (vertical sets of leaves). Top when you have 5-6 nodes, excluding those first cotyledons. That way your plant has a solid root structure to continue growth despite the topping. Good luck!

If you haven't seen the thread by Uncle Ben called Topping for Four Main Colas (or something like that) find it!

https://www.rollitup.org/general-marijuana-growing/13820-fimming-topping-101-a.html or as krypton advised https://www.rollitup.org/advanced-marijuana-cultivation/151706-uncle-bens-topping-technique-get.html

Cheers people sot on looks like I will be trying for 4 colas