Repotting guide

When & how to repot Walker's Low Catmint (Nepeta × faassenii 'Walker's Low')

Also called Walker's Low Catmint, Faassen's Catmint.

More about walker's low catmint

About Walker's Low Catmint

Nepeta × faassenii 'Walker's Low' · also called Walker's Low Catmint, Faassen's Catmint · flowering

Walker's Low Catmint is an RHS Award of Garden Merit winner prized for its long season of lavender-blue flower spikes and aromatic grey-green foliage. A tough, drought-tolerant perennial, it billows attractively at border edges. Cut back hard after the first summer flush to trigger prolific rebloom through autumn.

Mature size: 50–60 cm tall, 60–90 cm wide

How to tell walker's low catmint needs repotting

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

Roots spiralling thickly out of the drainage holes or pushing the whole plant up out of the pot.
The pot is so packed that water runs straight through in seconds and barely wets the soil.
It has split a plastic pot, or the rootball is a solid mass with almost no soil left when you slide it out.
Growth and (for walker's low catmint) flowering have clearly stalled despite good light and feeding — but remember this plant likes being snug, so a little crowding alone is not a reason to repot.

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 walker's low catmint

Only every 2–4 years, when genuinely crowded. Walker's Low Catmint is one of the plants that genuinely prefers a snug pot — it grows and flowers better with its roots a little restricted, so resist the urge to repot it on schedule. Mounding, spreading herbaceous perennial.

What size pot to step walker's low catmint up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Walker's Low Catmint positively prefers a snug pot: it flowers and grows better when the roots are a little restricted. The single biggest repotting mistake here is over-potting — dropping walker's low catmint into a pot two or three sizes up. All that surplus soil holds water the small root system cannot use, stays cold and wet, and rots the roots within weeks. When in doubt, choose the smaller pot.

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 walker's low catmint

Early spring, just as new growth restarts, is the ideal window for walker's low catmint. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting walker's low catmint

Confirm it actually needs it. Slide walker's low catmint out and check the roots. Only continue if it is genuinely packed — this plant prefers a snug pot, so if there is still soil and room, put it straight back.
Pick a pot only one size up. Choose a pot just 2–3 cm wider with good drainage. Resist anything bigger; over-potting is the main killer here.
Ease it out gently. Water lightly the day before, then tip walker's low catmint out, supporting the base. Tease the outer roots free only enough to stop them circling.
Repot at the same depth. Add a layer of fresh well-drained loam, sandy loam, or chalky soil; ph 6.0–8.0, set the plant so the soil line sits exactly where it did before, and backfill around the sides, firming lightly.
Settle it in. Water once to settle the soil, then let it sit. Hold off on more water until the top of the soil dries — fresh soil around a small root system stays wet for a while.

Aftercare

Because the new soil holds more water than the old crammed rootball did, ease right back on watering — let the top of the soil dry before you water walker's low catmint again, or you will rot the roots in the very pot you just moved it to. Keep it out of harsh direct sun for a fortnight. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for walker's low catmint

Walker's Low Catmint wants well-drained loam, sandy loam, or chalky soil; ph 6.0–8.0. Extremely adaptable — performs well on poor, stony, or alkaline soils where more demanding plants fail. Rich, wet soils cause excessive vegetative growth and flop. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting walker's low catmint — frequently asked questions

How often should you repot walker's low catmint?

Only every 2–4 years, when genuinely crowded for walker's low catmint. Only repot walker's low catmint every 2–4 years, and only when it is genuinely root-bound — it flowers and grows best slightly crowded. Step up just one pot size in spring using well-drained loam, sandy loam, or chalky soil; ph 6.0–8.0. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does walker's low catmint need?

When is the best time of year to repot walker's low catmint?

Does walker's low catmint like to be root-bound?

Yes — walker's low catmint genuinely flowers and grows best when slightly pot-bound, so do not rush to repot it. The mistake to avoid is over-potting into a much larger pot: the excess soil stays wet, the roots cannot use it, and the plant rots. Only repot every few years and only one snug size up.

Should you fertilise walker's low catmint after repotting?

Not immediately. Wait about 4 weeks after repotting walker's low 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.