Abstract: A stackable pallet system comprises a plurality of pallets used for holding and transporting various items, including potted plants such as potted trees, flowers, bushes, etc. When the pallets are to be stacked, two pairs of spacer pipes can be used on a first pallet extending upwardly therefrom. Two elongated saddles are then coupled, one to each pair of spacer pipes, such that the saddles extend between and unite the upper ends of the pairs of spacer pipes. The saddles comprise an upwardly facing, shallow channel which is sized to be slightly larger than at least a portion of the fork pockets contained on the pallet. A second pallet can be lowered down onto a first pallet with the fork pockets, or at least a portion of the fork pockets, being received in the saddle channels. Various containment rings can be coupled to the pipes, in place of or in addition to the saddles, to allow longer trees to be carried on the pallets or to allow double stacking of potted plants on a single pallet.