Repotting guide

When & how to repot Geranium cinereum var. subcaulescens (Geranium cinereum var. subcaulescens)

Also called Subcaulescent cranesbill, Vivid magenta cranesbill.

More about geranium cinereum var. subcaulescens

About Geranium cinereum var. subcaulescens

Geranium cinereum var. subcaulescens · also called Subcaulescent cranesbill, Vivid magenta cranesbill · flowering

Geranium cinereum var. subcaulescens is a low alpine cranesbill prized for intense, vivid magenta-crimson flowers with a striking near-black centre, carried over grey-green rosettes through summer. Sun-loving and compact, it brings electric colour to rock gardens, troughs, gravel and sharply drained border fronts, flowering longest where drainage is excellent.

Mature size: About 10-15 cm tall and 30 cm wide, forming a compact mound.

Watch for — Crown and root rot: Its main weakness, driven by wet or heavy soil and winter damp. Plant in sharp drainage, grit around the crown, and avoid covering the rosette with mulch.

How to tell geranium cinereum var. subcaulescens needs repotting

Repotting on a calendar is less reliable than reading the plant. For geranium cinereum var. subcaulescens, 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 geranium cinereum var. subcaulescens

Every 2–3 years, into bone-dry mix. Geranium cinereum var. subcaulescens's growth habit — low, compact, clump-forming alpine perennial making a tight grey-leaved rosette that increases slowly into a low cushion rather than running. — sets the pace. Geranium cinereum var. subcaulescens is a low alpine cranesbill prized for intense, vivid magenta-crimson flowers with a striking near-black centre, carried over grey-green rosettes through summer. Sun-loving and compact, it brings electric colour to rock gardens, troughs, gravel and sharply drained border fronts, flowering longest where drainage is excellent.

What size pot to step geranium cinereum var. subcaulescens up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Geranium cinereum var. subcaulescens 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 geranium cinereum var. subcaulescens

Spring or summer, while geranium cinereum var. subcaulescens 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 geranium cinereum var. subcaulescens

Repot dry. Do not water geranium cinereum var. subcaulescens 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 gritty, sharply drained neutral to alkaline 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 geranium cinereum var. subcaulescens 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 geranium cinereum var. subcaulescens 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 geranium cinereum var. subcaulescens

Geranium cinereum var. subcaulescens wants gritty, sharply drained neutral to alkaline soil. Requires free-draining, lean soil and will rot in heavy wet clay. Add plenty of grit or coarse sand, use gritty compost in troughs, and favour a neutral-to-alkaline pH. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting geranium cinereum var. subcaulescens — frequently asked questions

How often should you repot geranium cinereum var. subcaulescens?

Every 2–3 years, into bone-dry mix for geranium cinereum var. subcaulescens. Repot geranium cinereum var. subcaulescens every 2–3 years into a snug pot of gritty, sharply drained neutral to alkaline 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 geranium cinereum var. subcaulescens need?

When is the best time of year to repot geranium cinereum var. subcaulescens?

Should you water geranium cinereum var. subcaulescens after repotting?

No — not straight away. Repot geranium cinereum var. subcaulescens 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 geranium cinereum var. subcaulescens after repotting?

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