using soil in a micro grow, pot size being wider instead of deeper..make sense?

okay im startin my first little micro grow for the fuck of it, i got an attic an shed ive used an one using onw but this is or the fuck of if, next to my bed is a wodden night stand an its not very tall so i was thinking okay i cant use a very tall cup but what about if i use something wide? ... maybe like 4-5 inchs tall and about8-12inchs wide for the root room.. would that result in a wider plant an keep it short? .. or does it matter? im confused on this part.. can anyone chime in?

Roots will grow in any direction possable, any size or shape really. If you have a wide root mass it will help the plant become more stable so it might get wider, but defonatly taller aswell.

where the roots grow will not really affect how the plant looks up top for the most part. As long as the amount of soil is there and you have the 4-5 inches of depth, you should be ok. The top half of the plant will grow the same direction, UP. You can train the plant to keep it short, but this has nothing to do with the roots. I see people all the time running smaller rubbermaid or tupperware bins that are wide and short all the time, especially in a height restricted area. You are on the right track though, as your stem will start closer to the ground, and using different techniques to keep the plant short above ground usually require tying the plant down such as LST (low stress training) or under a screen (screen of green or SCRoG) or making cuts (FIM and Topping) or crushing parts of the plant's stems to send growth hormones to lower areas (supercropping). It is usually recommended you do not too many of these at once, or you could over-stress the plant and slow growth. All the terms i mentioned can be googled or searched for great explanations and tutorials. I hope I helped some. I am currently doing a grow with a scrog technique and have FIM'd the top to try and spread the plant's energy out instead of focusing on one cola like she will naturally want to do. These are all the most common ways to keep a plant short, and there are many different ways to go about it with almost all of them.