It is common to grow one amaryllis bulb per container, however you can grow several in a pot if it is large enough to house their large roots. The pot size for one amaryllis should be approximately seven inches deep one or two inches wider then the top of the bulb.This may seem small for such a large bulb, but amaryllis fair well when somewhat pot bound.f you purchase a dry bulb (no pot) in the fall and plant it up yourself you can save money (5-20 dollars Canadian), the selection of varieties is greater, and you can chose your own decorative pot instead of settling for the generic pots the full bloom plants come in.