Repotting guide

When & how to repot Garden Catmint (Nepeta × faassenii)

Also called Garden Catmint, Blue Catmint, Faassen's Catnip.

More about garden catmint

About Garden Catmint

Nepeta × faassenii · also called Garden Catmint, Blue Catmint · herb

Garden Catmint is a mounding, aromatic perennial prized for its lavender-blue flower spikes and silver-green foliage. A sterile hybrid, it blooms prolifically from late spring to autumn if cut back after the first flush. Drought-tolerant and deer-resistant, it thrives at border edges in full sun.

Mature size: 30–45 cm tall (12–18 in), 45–60 cm wide (18–24 in)

Watch for — Flopping after first bloom: Cut plants back by half immediately after the first flowering flush (typically early summer) to encourage a compact second flush of bloom and tidy growth.

How to tell garden catmint needs repotting

Repotting on a calendar is less reliable than reading the plant. For garden catmint, watch for these signs:

Roots circling the bottom of the module or pot, or poking out of the drainage holes.
The seedling dries out within a day and growth has visibly stalled.
Roots are white and matted in a tight spiral when you tip the plant out.
It has outgrown its current container for the stage of the season — pot garden catmint on before it becomes hard root-bound.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot garden catmint

Pot on seedlings as they grow; not a perennial repot. Garden Catmintis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Mounding, spreading perennial; forms neat clumps that may flop open after flowering.

What size pot to step garden catmint up to

Pot garden catmint on gradually — a seedling jumped straight into a huge pot sits in cold, wet, airless soil and stalls. Step up one or two sizes at a time as the roots fill each container, finishing in a large final pot or the ground. The aim is roots that never circle and never check.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot garden catmint

Pot garden catmint on through the active growing season, whenever roots fill the current container — there is no single date, just "before it becomes root-bound". Avoid potting on during a cold snap.

Step-by-step: repotting garden catmint

Pot on before it is root-bound. Check garden catmint regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
Step up one or two sizes. Choose the next container up — not a giant one. Cold, wet, unused soil around a small root system stalls seedlings.
Knock it out gently. Support the stem, tip the pot, and ease the rootball out without breaking it. A little teasing of circled roots at the base is fine.
Pot into rich mix. Set it into fresh well-drained loam or sandy loam at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water garden catmint in well and keep it in bright light; a freshly potted-on seedling can wilt for a day while roots settle, so do not overcompensate by drowning it. Do not fertilise for about 1 week — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for garden catmint

Garden Catmint wants well-drained loam or sandy loam. Thrives in average to lean, well-drained soil (pH 6.0–7.5). Tolerates poor, dry soils. Wet, clay-heavy soils are the primary cause of failure. No amendment with rich compost needed. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting garden catmint — frequently asked questions

How often should you repot garden catmint?

Pot on seedlings as they grow; not a perennial repot for garden catmint. Garden Catmint is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into well-drained loam or sandy loam so the roots never circle the cell, ending in a large final container. A root-bound transplant stalls and never fully recovers.

What size pot does garden catmint need?

When is the best time of year to repot garden catmint?

Can you put garden catmint straight into a much bigger pot?

No. Even a fast-growing garden catmint should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise garden catmint after repotting?

Not immediately. Wait about 1 week after repotting garden catmint. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.