Repotting guide

When & how to repot Sticky Primrose (Primula viscosa)

Also called Sticky primrose, Clammy primrose.

More about sticky primrose

About Sticky Primrose

Primula viscosa · also called Sticky primrose, Clammy primrose · flowering

Primula viscosa is a compact evergreen alpine perennial native to the limestone and acidic scree of the western Alps and Pyrenees, where it grows at elevations between 1,500 and 3,000 metres. The entire plant — stems, leaf undersides, and flower stalks — is covered in sticky, glandular hairs that trap small insects, reducing water loss and providing some protection from grazing. It produces clusters of fragrant, pink to rose-purple flowers with a yellow eye in spring. Excellent drainage and protection from winter wet are the non-negotiable conditions for success. This species is toxic to cats, dogs, and horses.

Mature size: 8–15 cm tall in flower, spreading 10–20 cm wide.

How to tell sticky primrose needs repotting

Repotting on a calendar is less reliable than reading the plant. For sticky primrose, 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 sticky primrose

Every 2–3 years, into bone-dry mix. Sticky Primrose's growth habit — compact, rosette-forming evergreen perennial, slowly clump-forming. — sets the pace. Primula viscosa is a compact evergreen alpine perennial native to the limestone and acidic scree of the western Alps and Pyrenees, where it grows at elevations between 1,500 and 3,000 metres. The entire plant — stems, leaf undersides, and flower stalks — is covered in sticky, glandular hairs that trap small insects, reducing water loss and providing some protection from grazing. It produces clusters of fragrant, pink to rose-purple flowers with a yellow eye in spring. Excellent drainage and protection from winter wet are the non-negotiable conditions for success. This species is toxic to cats, dogs, and horses.

What size pot to step sticky primrose up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Sticky Primrose 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 sticky primrose

Spring or summer, while sticky primrose 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 sticky primrose

Repot dry. Do not water sticky primrose 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 well-drained, gritty alpine compost, ph 6.0–7.0 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 sticky primrose 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 sticky primrose 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 sticky primrose

Sticky Primrose wants well-drained, gritty alpine compost, ph 6.0–7.0. Thrives in a moisture-retentive yet free-draining mix of loam, leaf mould, and coarse grit; neutral pH suits both the calcareous and siliceous ecotypes found in the wild. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting sticky primrose — frequently asked questions

How often should you repot sticky primrose?

Every 2–3 years, into bone-dry mix for sticky primrose. Repot sticky primrose every 2–3 years into a snug pot of well-drained, gritty alpine compost, ph 6.0–7.0, 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 sticky primrose need?

When is the best time of year to repot sticky primrose?

Should you water sticky primrose after repotting?

No — not straight away. Repot sticky primrose 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 sticky primrose after repotting?

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