Only time I grew out 2 plants in a 5 gallon bucket is when I was making my Glass Slipper seeds… The plants were maybe 2 1/2 feet tall, and it worked out great! So, I think it would be “ok” for what your doing. Im growing a 10 foot plant outside right now, in a 5 gallon bucket, and its doing wonderful. But, I have to water everyday. Why not buy more buckets?.. 