I have kept moms for years in a small space...bonsai style all the way. Does not take much at all and they do not need a ton of light. This cab measured about 18x29 with 192 watts of t-5 ho. It is not tall either as you can see. Room for plenty more....
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Peace, negative.
That should work well. My room is 5x4x7H and houses eight mothers/vegging plants as well as a 2x4 heat mat with clone trays. Also houses all storage for nutes and grow room materials as well as the 30 gallons rez for my flower room. It's all a matter of creative and efficient use of space. Think vertically.
Over 10 years here, and I definitely vote for bonsai mums as well. You may (depending on your style/setup) want a separate veg chamber with a bit more space and light. Larger plants take a bit longer to create, especially when you start with such small clones or slow growing mums.I have kept moms for years in a small space...bonsai style all the way.