For use in containers we recommend a minimum of 50L volume for each fast-growing annual plant.  If you exceed the number of fast-growing annuals per 50L pot by more than 1, less than satisfactory performance may be observed.  This is due to not enough soil biology necessary to meet the demands of your plants. Set yourself up for success from the start and if planting nutrient-hungry, fast-growing annuals, ensure there is at least 50L of soil to meet plant needs.  Success in no-till organic growing is directly relative to the volume of soil you have to work with. Try to use the rule above as a minimum and bear in mind that as you increase this volume, so too will the performance of your crops. We recommend fabric pots which encourage an aerobic environment in the root zone.  The microbes we want in the soil food web thrive in aerobic environments so when using containers this is a no-brainer. We like to use GeoPots or Root Pouch as they are very high quality and will last for years.