How many tomato plants per grow bag?

Plant one tomato plant per grow bag for best results. In a 15-litre bag, one plant has adequate root space and airflow. In a 25-litre bag, you can push to two plants but yields per plant will be lower and disease pressure increases with crowding. Cherry tomato varieties are more forgiving — two plants in a 20-litre bag works. Always use one plant per bag for indeterminate (tall) varieties.