Repotting guide

When & how to repot London Pride (Saxifraga urbium)

Also called London Pride, None-so-Pretty, St Patrick's Cabbage hybrid.

More about london pride

About London Pride

Saxifraga urbium · also called London Pride, None-so-Pretty · flowering

London Pride is a tough, semi-evergreen perennial forming dense rosettes of rounded, leathery leaves. In late spring it sends up airy 30 cm stems bearing delicate pink-flushed white star-shaped flowers. Exceptionally shade and pollution tolerant, it thrives in urban gardens, rockeries, and wall crevices, spreading slowly by stolons.

Mature size: 25–30 cm tall in flower, rosettes spreading to 40–60 cm across over several years

Watch for — Vine weevil grub damage: Creamy-white grubs feed on roots through winter, causing plants to suddenly wilt and collapse. Apply nematode biological controls (Steinernema kraussei) to moist soil in autumn when soil temperature is above 5°C.

How to tell london pride needs repotting

Repotting on a calendar is less reliable than reading the plant. For london pride, 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 london pride) 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 london pride

Only every 2–4 years, when genuinely crowded. London Pride 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. Mat-forming, rosette-producing semi-evergreen perennial spreading by short stolons.

What size pot to step london pride up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. London Pride 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 london pride 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 london pride

Early spring, just as new growth restarts, is the ideal window for london pride. 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 london pride

Confirm it actually needs it. Slide london pride 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 london pride 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 moist, humus-rich, well-drained soil; tolerant of a wide range, 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 london pride 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 london pride

London Pride wants moist, humus-rich, well-drained soil; tolerant of a wide range. Adaptable to most soils including chalk and clay as long as drainage is adequate. Prefers slightly acid to neutral pH (5.5–7.0). Incorporating leaf mould or garden compost at planting improves moisture retention. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting london pride — frequently asked questions

How often should you repot london pride?

Only every 2–4 years, when genuinely crowded for london pride. Only repot london pride 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 moist, humus-rich, well-drained soil; tolerant of a wide range. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does london pride need?

When is the best time of year to repot london pride?

Does london pride like to be root-bound?

Yes — london pride 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 london pride after repotting?

Not immediately. Wait about 4 weeks after repotting london pride. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.