Grow area is much too short, but if that's all you got....
Individual pots would be smarter because if something goes wrong with one, it won't necessarily affect the others.
Worm castings, but not sure if they have enough nitrogen. Pure Blend fert might be good.
You could just cut the male at its base and that would be that. Make sure you use big enough containers for long enough grow in order to get plants to mature and flower. 18 inches isn't enough height.