When and How to Pot On Rooted Cuttings

Potting on is the process of moving a rooted cutting or young plant from its initial small container into a progressively larger one as the root system grows. It sounds straightforward but is one of the stages where well-rooted plants most often fail — either moved too early before roots are established enough to survive disturbance, or left too long until the plant becomes root-bound and stressed. Timing, correct pot sizing, and the right compost choice all matter here.

Signs That a Cutting Is Ready to Pot On

The most reliable sign is roots visible at the drainage holes of the pot — this indicates the root system has fully explored the available volume and needs more space. A plant that dries out very rapidly between waterings is also likely root-bound. Do not pot on simply because the plant looks large above the surface; what matters is the root system below. A young plant that is actively growing with healthy green leaves but whose roots have not yet reached the pot edges is better left in its current container.

Choosing the Right Pot Size

The most common potting-on mistake is using a pot that is too large. Placing a small root ball into a large container means the surrounding compost stays wet long after the plant has absorbed what it needs, creating the anaerobic conditions that cause root rot. Move up by one pot size at a time — from a 7 cm cell to a 9 cm pot, then to a 1-litre pot, and so on. Each increase gives the roots just enough new space to expand into without creating an excess of wet, unoccupied compost around them.

Compost Choice for Potting On

Once you are moving beyond the initial rooting medium, switch to a proper growing compost. Peat-free multipurpose compost suits most cuttings at the first pot-on stage. For woody plants, a loam-based compost such as John Innes No. 2 provides better structure and nutrient retention for a longer period. Succulents should go into cactus compost or a 50:50 blend of multipurpose and grit. Avoid adding heavy garden soil to pot mixes — it compacts over time, reduces drainage, and introduces soil pathogens.

The Potting-On Process

Water the plant an hour before potting on so the root ball holds together when removed. Ease the root ball out of its pot by inverting and gently squeezing flexible pots, or sliding a dibber around the edge of rigid ones. Place a small layer of compost in the bottom of the new pot, set the root ball in the centre at the correct depth — the crown should sit at the same level as before — and fill around the sides. Firm gently and water in. Avoid burying the stem deeper than it was previously growing, as this causes stem rot in most species.