Editor's note: This article has been reviewed and updated for accuracy in 2026. When it comes to cultivating your own weed, you want to make sure that the methods you’re using are as efficient as possible. This is especially true if you’re growing indoors, where space is limited, but it’s the case if you have ample room to spread out in a greenhouse or a garden. With that said, one of the biggest challenges that cannabis cultivators face is how to maximize the space they’re using to grow their crops, while also ensuring that each and every plant receives as much light (via complex indoor lighting systems) and oxygen as possible (via strategically placed ventilation fans). When cannabis cultivation started to shift to indoor growing during the 1980s and 1990s, growers had to come up with ways to get the most out of the limited space that they had to work with so that they could produce as many healthy and robust plants as possible. As the saying goes, “necessity is the mother of invention”, and as such, the pioneers of indoor cultivation came up with an ideal solution for the limited amounts of space they had to work with, and that solution quickly gained traction amongst cannabis growers. It’s called “the sea of green” method. Whether you’re an experienced cultivator and you’re