For a 25-gallon grow bag, you should plant 2-3 seed potatoes depending on their size and your growing objectives.
Here's the calculation: A 25-gallon container provides approximately 95 liters or 0.095 cubic meters of growing space. Based on ICAR-CPRI and FAO spacing guidelines, standard potato spacing is 20-30 cm between plants. In a container this size, you can effectively space 2-3 seed potatoes with adequate room for root and tuber development.
Specific recommendations by seed size:
- Small seed potatoes (40-50g): Plant 3 tubers
- Medium seed potatoes (50-70g): Plant 2-3 tubers
- Large seed potatoes (70-100g): Plant 2 tubers
According to University Extension Services data, denser planting produces more but smaller tubers, while wider spacing yields fewer but larger tubers. In container growing, 2-3 plants per 25-gallon bag strikes the optimal balance for good-sized tubers without overcrowding.
The ICAR-CPRI standard of 60 x 20 cm spacing translates well to container growing, where you want roughly 20-25 cm between seed pieces. This spacing allows each plant adequate soil volume (about 30-45 liters per plant) for proper tuber development while maximizing your harvest from the available space.