You could try hydro...then you can have more than one, but here is my tip...if you have caused nute burn recently to a plant in soil then don't do it...but if you are easy with the nutesw and are willing to get a Reverse Ormosis Filter, or buy distilled water every week, then go buy some rubbermaid totes and watch some DIY videos and set it up...you could grow more than 2 if you wanted, but with soil there are constraints unless you can find really tall skinny pots...which I am going to see what weird and odd shaped pots I can find that will make my roots need to go down as opposed to out so I can have a little more room...Tall and skinny if you have a tall skinny space short and fat if you need short and fat. That is my best idea but for real I vegged all my plants for one month...1...and now 4 weeks in flowering one got rootbound in a 3 gallon and I totally thought it would finish in a 3 but it started looking pale and growing slow after growing super fast So, I checked and it was totally out of room in the 3 gallon...so I put it in a 6 and hopefully it will stay there for another month or so...You could kind of bonsai, or grow autoflowers, they are smaller I have heard. There is always some way to make things work...you just have to figure it out.