Repotting guide

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

Also called garden catmint, Faassen's catmint.

More about garden catmint

About Garden Catmint

Nepeta x faassenii · also called garden catmint, Faassen's catmint · flowering

Garden catmint is a sterile, clump-forming perennial prized for soft grey-green aromatic foliage and long sprays of lavender-blue flowers from late spring into autumn. A magnet for bees and butterflies, it thrives in poor, free-draining soil and full sun, shrugging off heat and drought. Shearing spent flowers triggers a fresh, tidy second flush.

Mature size: 30-45 cm tall and 45-60 cm wide.

Watch for — Flopping after flowering: Stems splay open mid-season, especially in rich soil. Shear the whole plant back by a third to half once the first flush fades to force compact regrowth and a second bloom.

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 growing out of the drainage holes, or the rootball lifting the plant proud of the rim.
Soil that has shrunk away from the pot sides and no longer holds water.
The pot is unstable because the plant has grown top-heavy.
Old, compacted, broken-down mix that stays wet too long — for a succulent that is a rot risk, so refresh it even if the pot size is fine.

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

Every 2–3 years, into bone-dry mix. Garden Catmint's growth habit — low, spreading mound of branching aromatic stems forming a soft, billowing dome that spills gracefully over path edges and borders. — sets the pace. Garden catmint is a sterile, clump-forming perennial prized for soft grey-green aromatic foliage and long sprays of lavender-blue flowers from late spring into autumn. A magnet for bees and butterflies, it thrives in poor, free-draining soil and full sun, shrugging off heat and drought. Shearing spent flowers triggers a fresh, tidy second flush.

What size pot to step garden catmint up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Garden Catmint stores water and rots in a large pot of slow-drying soil. A tight terracotta pot that dries fast is far safer than a generous plastic one. Never up-pot a succulent by several sizes.

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

Spring or summer, while garden catmint is in active growth and warm, is best — roots recover fastest then, and the plant is not sitting in cool damp soil. Avoid repotting a succulent in winter dormancy.

Step-by-step: repotting garden catmint

Repot dry. Do not water garden catmint for several days first. Working with dry roots and dry mix dramatically lowers the rot risk for a succulent.
Pick a snug, fast-draining pot. Choose terracotta one size up at most, with a drainage hole. Have gritty lean, sharply drained loam or sandy soil, neutral to slightly alkaline ready.
Tip it out and clean the roots. Slide the plant out, crumble off the old soil, and trim any black, mushy or dead roots with clean snips.
Pot into dry mix. Set garden catmint at its original depth in dry gritty mix, firming gently. Do not bury the stem deeper than it was.
Wait a week before watering. Leave it completely dry and out of harsh sun for about 7 days so any damaged roots callus. Only then water lightly.

Aftercare

Keep garden catmint completely dry and out of fierce sun for about a week so any nicked roots callus before they meet moisture; watering a freshly repotted succulent is the classic way to rot it. Then resume the normal lean, dry rhythm. Do not fertilise for about 3 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for garden catmint

Garden Catmint wants lean, sharply drained loam or sandy soil, neutral to slightly alkaline. Tolerates poor, gritty, even chalky ground. Avoid rich, moisture-retentive soils, which produce floppy, short-lived plants. Add grit to heavy clay. 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?

Every 2–3 years, into bone-dry mix for garden catmint. Repot garden catmint every 2–3 years into a snug pot of lean, sharply drained loam or sandy soil, neutral to slightly alkaline, ideally in spring or summer. Let it sit in dry soil and do not water for about a week afterwards so any nicked roots can callus. Over-potting and watering straight away is what rots succulents.

What size pot does garden catmint need?

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

Should you water garden catmint after repotting?

No — not straight away. Repot garden catmint into dry mix and wait about a week before the first watering so any damaged roots callus over. Watering a freshly repotted succulent is the single most common way to rot one.

Should you fertilise garden catmint after repotting?

Not immediately. Wait about 3 weeks 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.