Repotting guide

When & how to repot Blue Chalk Sticks (Senecio mandraliscae)

Also called Blue Chalk Sticks, Blue Fingers, Blue Chalksticks.

More about blue chalk sticks

About Blue Chalk Sticks

Senecio mandraliscae · also called Blue Chalk Sticks, Blue Fingers · houseplant

A spreading South African succulent with striking upright, finger-like blue-grey leaves that grow in dense clumps reaching 45 cm tall. Excellent as a drought-tolerant ground cover in frost-free gardens (USDA 9–11) or as a bold indoor specimen in a sunny spot. Very low maintenance. Toxic to pets.

Mature size: 30–45 cm (12–18 in) tall; spreading 60–90 cm (24–36 in) wide over several years

How to tell blue chalk sticks needs repotting

Repotting on a calendar is less reliable than reading the plant. For blue chalk sticks, 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 blue chalk sticks

Every 2–3 years, into bone-dry mix. Blue Chalk Sticks's growth habit — spreading, clump-forming succulent with upright, cylindrical glaucous-blue leaves; spreads slowly by offshoots — sets the pace. A spreading South African succulent with striking upright, finger-like blue-grey leaves that grow in dense clumps reaching 45 cm tall. Excellent as a drought-tolerant ground cover in frost-free gardens (USDA 9–11) or as a bold indoor specimen in a sunny spot. Very low maintenance. Toxic to pets.

What size pot to step blue chalk sticks up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Blue Chalk Sticks 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 blue chalk sticks

Spring or summer, while blue chalk sticks 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 blue chalk sticks

Repot dry. Do not water blue chalk sticks 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 sandy, gritty, well-draining succulent mix 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 blue chalk sticks 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 blue chalk sticks 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 blue chalk sticks

Blue Chalk Sticks wants sandy, gritty, well-draining succulent mix. Use a cactus and succulent potting mix cut with 30–40% coarse sand, perlite, or pumice. Outdoors, amend clay soils heavily with grit. Excellent drainage is non-negotiable; standing water causes crown rot within days. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting blue chalk sticks — frequently asked questions

How often should you repot blue chalk sticks?

Every 2–3 years, into bone-dry mix for blue chalk sticks. Repot blue chalk sticks every 2–3 years into a snug pot of sandy, gritty, well-draining succulent mix, 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 blue chalk sticks need?

When is the best time of year to repot blue chalk sticks?

Should you water blue chalk sticks after repotting?

No — not straight away. Repot blue chalk sticks 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 blue chalk sticks after repotting?

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