Pro Mix MP Mycrorrhizae organic potting soil works great for growing cannabis plants from seed to harvest. It's a high porosity peat-based growing medium that ensures optimal growth for cannabis plants that need higher air capacity and awesome drainage for the roots. And the mycorrhizae ensures you'll have a beneficial ecosystem full of endomycorrhizal fungas, too. Pro Mix HP Mycorrhizae is top-shelf potting soil for cannabis gardeners.
You could always make your own special soil blend. You could add soilless mediums to potting soil like perlite, vermiculite, peat, cocoa, and mycorrhizae, sure. That's fine if you're dead set on doing things the hard way.
Pro Mix MP Mycrorhizae Organic Soil comes with everything you need for a great base soil to grow cannabis plants in. It's not too hot either like some other soils being marketed for cannabis - you don't need to cut it with less-active grow mediums and it's not going to burn your young cannabis plants. It contains a base 60-70% sphagnum peat moss, core fiber (a lot like peat, helps with water retention), perlite (better aeration and drainage), yucca (helps with water retention and absorption), lime (for PH adjustment), starter fertilizer charge (organic chicken manure and seaweed for macro and micronutrients for approximately the first two weeks of growth), and some other great stuff for cannabis plants, too.
Gardening in soil makes watering flow smooth. When you're watering your cannabis plants, water until the container feels heavy - usually, just until you notice the water is starting to drip out of the bottom of the pot. The plant container's going to be heavy because it's fully saturated with water. After the plant eats and the soil has time to dry a little, you'll notice the plant container will feel much lighter. Feeling out a watering schedule based on container weight is simple and works better than waiting for visual signs from the leaves that a plant is thirsty for a drink.
Pro Mix MP Mycrorhizae Organic Soil provides superior overall growth, substantial crop yields, and plants that are better able to defend against environmental stresses.