Pros And Cons Of Trimming Cannabis Plants
For very young plants such as yours, pruning is generally not needed. Where confusion sets in for newer growers is when they hear talk about advanced pruning techniques such as “topping” or “pinching off” a young plant in order to help induce more top colas. These types of pruning techniques are usually reserved for advanced growers, but if you feel you have a green thumb and are attentive to your garden’s needs on a daily basis, you can certainly try these techniques at home at any time.
In general, a small plant like yours (10”, five leaf sets) is pretty young to begin any sort of pruning program. I usually recommend that a growers wait for a plant to get out of the seedling/ clone/ rooting phase and wait until it has been transplanted into a larger (or final) container before beginning any type of pruning program as trimming off leaves or topping plants can shock young plants.
Plants that have been transplanted and in a solid vegetative state for two or more weeks can be topped, pinched-off or FIMed to create more top colas (see hyperlinks above for more info). But actual pruning or trimming of leaves won’t be necessary until the plant becomes fuller and bushier towards the end of veg and into flower.