Repotting guide

When & how to repot Grayleaf Cranesbill (Geranium cinereum)

Also called Grayleaf Cranesbill, Ashy Cranesbill, Grey-Leaved Cranesbill.

More about grayleaf cranesbill

About Grayleaf Cranesbill

Geranium cinereum · also called Grayleaf Cranesbill, Ashy Cranesbill · flowering

Geranium cinereum is a compact alpine perennial native to the Pyrenees and adjacent mountains of northern Spain and southern France, forming tidy low clumps of grey-green, deeply divided leaves. It produces a long succession of pale pink to white flowers with dark purple veining from late spring to midsummer, making it ideal for rock gardens, troughs, and the front of well-drained borders. Sharp drainage is the single most critical care requirement; this plant will rot quickly in wet, poorly drained soils. True Geranium species are non-toxic to cats and dogs per ASPCA guidance.

Mature size: 15–20 cm tall and 25–30 cm wide.

Watch for — Root and crown rot: The most serious threat; caused by waterlogged soil, especially in wet UK winters. Plant on a raised alpine bed, surround the crown with a collar of coarse grit, and ensure water drains freely away from the roots at all times.

How to tell grayleaf cranesbill needs repotting

Repotting on a calendar is less reliable than reading the plant. For grayleaf cranesbill, 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 grayleaf cranesbill

Every 2–3 years, into bone-dry mix. Grayleaf Cranesbill's growth habit — compact, cushion-forming, semi-evergreen alpine perennial. — sets the pace. Geranium cinereum is a compact alpine perennial native to the Pyrenees and adjacent mountains of northern Spain and southern France, forming tidy low clumps of grey-green, deeply divided leaves. It produces a long succession of pale pink to white flowers with dark purple veining from late spring to midsummer, making it ideal for rock gardens, troughs, and the front of well-drained borders. Sharp drainage is the single most critical care requirement; this plant will rot quickly in wet, poorly drained soils. True Geranium species are non-toxic to cats and dogs per ASPCA guidance.

What size pot to step grayleaf cranesbill up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Grayleaf Cranesbill 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 grayleaf cranesbill

Spring or summer, while grayleaf cranesbill 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 grayleaf cranesbill

Repot dry. Do not water grayleaf cranesbill 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, alkaline or neutral gritty soil 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 grayleaf cranesbill 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 grayleaf cranesbill 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 grayleaf cranesbill

Grayleaf Cranesbill wants lean, sharply drained, alkaline or neutral gritty soil. Best in a scree or rock garden mix: one part loam, one part leaf mould, and two parts horticultural grit. Avoid rich soils, which produce coarse, floppy growth out of character for this alpine. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting grayleaf cranesbill — frequently asked questions

How often should you repot grayleaf cranesbill?

Every 2–3 years, into bone-dry mix for grayleaf cranesbill. Repot grayleaf cranesbill every 2–3 years into a snug pot of lean, sharply drained, alkaline or neutral gritty soil, 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 grayleaf cranesbill need?

When is the best time of year to repot grayleaf cranesbill?

Should you water grayleaf cranesbill after repotting?

No — not straight away. Repot grayleaf cranesbill 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 grayleaf cranesbill after repotting?

Not immediately. Wait about 3 weeks after repotting grayleaf cranesbill. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.