Repotting guide

When & how to repot Piper's Bellflower (Campanula piperi)

Also called Piper's Bellflower, Olympic Bellflower.

More about piper's bellflower

About Piper's Bellflower

Campanula piperi · also called Piper's Bellflower, Olympic Bellflower · flowering

Piper's Bellflower is a rare, endemic alpine native to the Olympic Mountains of Washington State, USA. It produces upward-facing, blue-violet flowers on tufted 5–10 cm plants in midsummer, growing from rocky crevices in subalpine scree. An extraordinary specialist plant for skilled alpine gardeners, it requires near-perfect drainage and cool summer conditions.

Mature size: 5–10 cm tall, spreading 10–20 cm wide

Watch for — Crown rot: Any moisture sitting on the crown or in poorly drained pots is rapidly fatal. Use a deep layer of grit as a top-dressing and water only at the base or from below.

How to tell piper's bellflower needs repotting

Repotting on a calendar is less reliable than reading the plant. For piper's bellflower, 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 piper's bellflower

Every 2–3 years, into bone-dry mix. Piper's Bellflower's growth habit — tufted, cushion-forming perennial; small rosettes of slightly toothed leaves emerging from rocky substrate — sets the pace. Piper's Bellflower is a rare, endemic alpine native to the Olympic Mountains of Washington State, USA. It produces upward-facing, blue-violet flowers on tufted 5–10 cm plants in midsummer, growing from rocky crevices in subalpine scree. An extraordinary specialist plant for skilled alpine gardeners, it requires near-perfect drainage and cool summer conditions.

What size pot to step piper's bellflower up to

Use a pot only one size up — or even the same pot with fresh gritty mix if the roots have room. Piper's Bellflower 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 piper's bellflower

Spring or summer, while piper's bellflower 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 piper's bellflower

Repot dry. Do not water piper's bellflower 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 ultra-gritty scree or rock garden mix; slightly acidic 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 piper's bellflower 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 piper's bellflower 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 piper's bellflower

Piper's Bellflower wants ultra-gritty scree or rock garden mix; slightly acidic. Use a very lean mix of one part loam to four parts coarse grit or crushed granite. Slightly acidic to neutral pH (5.5–6.8), unlike many European alpine Campanulas. Tufa rock is an excellent host medium. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting piper's bellflower — frequently asked questions

How often should you repot piper's bellflower?

Every 2–3 years, into bone-dry mix for piper's bellflower. Repot piper's bellflower every 2–3 years into a snug pot of ultra-gritty scree or rock garden mix; slightly acidic, 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 piper's bellflower need?

When is the best time of year to repot piper's bellflower?

Should you water piper's bellflower after repotting?

No — not straight away. Repot piper's bellflower 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 piper's bellflower after repotting?

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