Potting On Seedlings

Seedlings grown in pots and trays sometimes need potting on before being transplanted into their final location in a container or the soil. This inbetween stage gives seedlings the extra space and compost they need to continue growing strongly. Two similar techniques are explained here: ‘pricking out’ and ‘potting on’. 

Pricking out

This technique moves seedlings from one small container to another, usually from pots or ‘seed-trays’ to larger pots or modular trays where seedlings can grow on individually rather than in clumps. This is done before seedlings become overcrowded and while still small so the roots aren’t too entangled. Many gardeners choose not to prick out, preferring to sow seed direct into pots or modular trays to save time and the risk of damaging seedlings. However, this extra stage is useful on the following occasions:

• When unsure of the likely germination rate, eg where poor germination in modular trays would leave a lot of wasted space.
• For getting as many seedlings as possible, where every seedling is needed and grown on.
• When there isn’t space to sow direct into modular trays, eg where the space for raising plants is already full.

Potting into larger pots

This technique gives seedlings in their own pots or modular trays more space to grow, eg pepper and tomato plants need re-potting several times. This builds up the plant’s strength before transplanting into a large final container or into the soil. Potting on may also be necessary if there is delay in transplanting (to keep plants growing strongly).