Zativo caters to private customers only, and does not supply commercial or industrial growers with large amounts of cannabis seeds. If we have reason to suspect that the ordered seeds are destined for growing cannabis on a larger-than-private scale, we reserve the right to dismiss that specific order.
Cannabis plants, like all plants, naturally compete for light. You may find that a particularity tall cannabis plant in your grow area has grown too tall and is blocking light from a lot of the other cannabis plants in the area. Thinning your cannabis plants is the process of cutting away excess foliage to reduce this competition, to make sure that all of your cannabis plants are receiving optimal amounts of light.
This is especially going to be a very effective technique if you are growing new marijuana hybrids that have just entered the market, strains that have not yet been fully established and are likely to be unstable. Whilst most stable strains will all grow rather uniform, new, unstable hybrids may have a lot of genetic variation seed to seed This will likely cause the cannabis plants within your grow area to grow at different rates and heights. Cutting back one for the benefit of the masses is going to get you better end results – by removing the foliage on one large plant, you create a more even canopy, allowing for much better light distribution.
Thinning is generally a technique utilized more by the outdoor grower, as their cannabis is often competing with multiple types of plants in addition to their brethren; but it is not unheard of for an indoor cultivator to need to thin their crop, especially in the above hybrid example, or if you are using the sea of green/screen of green technique.
When growing cannabis you should be aiming to have an even canopy. Any cannabis plant that stretches above the canopy is going to be reducing the light received by those around it, making for an inefficient grow room. If one of your plants is getting to vigorous then cut it down to the same height as the other cannabis plants around it, or even potentially remove it from the area. Keep the section you cut down - you can use this to create clones if you are quick (a batch of clones is unlikely to need thinning as they will replicate the exact genetics of the mother).
Remember height and size has nothing to do with potency. Do not be tempted to remove the smaller plants in favor of the larger. Quite often plants that are growing taller than the rest can end up being male; so don't actually remove them until you know the sex of the cannabis plant if you can help it. By maintaining an even canopy you are going to end up with healthier plants and an overall higher yield due to a better all round crop performance.