If you are using Joel’s methods, as referenced in the ‘Wild Your Garden’ book and on Joel’s Youtube channel, appropriate marginal plants can be planted in the sub-soil areas around the edge of the pond. In these cases, you will not need to “re-pot” your 9cm pots, as they will go straight into the sub-soil.
However, if you are not using sub-soil and are going for a more formal look, the 9cm pots should be re-planted into an appropriate 1l size container or otherwise before being placed in or around your pond.
Container grown marginals should be placed in trays of water so that their roots may absorb the moisture. All sizes and planting depths are a guide only and considerable variation in the depth of water over the soil will be tolerated by most aquatics.
All plants in 1 litre containers and larger are in their final mesh basket and do not require repotting. However, we recommend 9cm plants are re-potted up to a minimum of 1 litre.