Planting out
‘Planting out’ is the process of taking plants growing in containers and planting them into open soil.
You often use this phrase in association with plant propagation; once cuttings or seedlings have grown big enough, and been hardened off if necessary, they are ‘planted out’ into the soil.
It can also refer to plants purchased in containers which are then ‘planted out’ into the garden.
Where seeds are sown into the soil directly, this is generally not considered to be ‘planting out’.