A medium-size rubberized container will do. We used a potting medium that is a combination of rice hull, garden soil and Durabloom organic fertilizer. It is interesting because the potted marcot readily bears fruit just one year after planting. The potted seedless guava should be regularly fertilized (monthly) with complete as well as organic fertilizer. Better still if the leaves are sprayed with Power Grower Combo and Heavy Weight Tandem formulated by our friend Alfonso G. Puyat.
Photo shows a two-year-old seedless guava with a couple of fruits in a medium-size rubberized container.