Repotting guide

When & how to repot Variable-Leaved Butterwort (Pinguicula heterophylla)

Also called Variable-leaved butterwort, Mexican butterwort.

More about variable-leaved butterwort

About Variable-Leaved Butterwort

Pinguicula heterophylla · also called Variable-leaved butterwort, Mexican butterwort · houseplant

Pinguicula heterophylla is a carnivorous butterwort endemic to the Mexican states of Morelos, Guerrero, and Oaxaca, where it grows in mountainous terrain. Its common and species names refer to its striking dimorphic leaves — tall, upright, narrow carnivorous leaves in summer that resemble threadleaf sundews, contrasting with a compact subterranean onion-like bulb in winter — the single most important care fact is that this bulb must be kept completely bone-dry during winter dormancy or it will rot within days. It is not confirmed as non-toxic on the ASPCA database and carries a precautionary mildly-toxic rating.

Mature size: Active rosette up to 15 cm tall and 10-15 cm across; bulb 1-2 cm diameter; flowers violet on scapes 10-20 cm tall in spring.

Watch for — Bulb rot during winter dormancy: Any moisture reaching the dormant bulb — even high ambient humidity — can cause rapid rot. Remove from the tray immediately when leaves begin to die back, store in a dry spot, and do not water at all until new leaf tips emerge in spring.

How to tell variable-leaved butterwort needs repotting

Repotting on a calendar is less reliable than reading the plant. For variable-leaved butterwort, watch for these signs:

Flowering has tailed off year on year and the clump has become congested and overcrowded.
Lots of leaf and few flowers — a classic sign that variable-leaved butterwort bulbs or tubers need lifting and dividing.
Bulbs visibly bursting the pot or pushing each other to the surface.
It is the natural dormancy window (foliage yellowed and died back) — the only safe time to lift and split.

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 variable-leaved butterwort

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, variable-leaved butterwort is lifted and divided once the clump congests and flowering drops off. Produces tall, upright, narrow glandular carnivorous leaves (to 15 cm) in summer in a rosette form; retreats entirely to a subterranean onion-like bulb in winter..

What size pot to step variable-leaved butterwort up to

Pot size matters less than depth and spacing here. When you replant variable-leaved butterwort, set the bulbs or tubers at the correct depth (a rough guide: two to three times their own height of soil over the top) and space them so they are not touching. A wide, shallow pot suits a clump better than a tall narrow one.

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 variable-leaved butterwort

The only safe window is dormancy: wait until the foliage has yellowed and died back naturally, lift and divide then, and replant before or at the start of the next growing season. Disturbing variable-leaved butterwort in full growth or flower sets it back badly.

Step-by-step: repotting variable-leaved butterwort

Wait for dormancy. Let variable-leaved butterwort foliage yellow and die back completely. Lifting while it is in growth wastes the energy it is storing for next year.
Lift carefully. Loosen the soil well away from the bulbs/tubers with a fork and ease the whole clump out without spearing them.
Separate the offsets. Gently pull the clump apart into individual bulbs or tubers. Keep only firm, healthy, blemish-free ones.
Replant at the right depth. Reset them in fresh very free-draining mineral mix, nutrient-poor at the correct depth and spacing — not touching — so each has room to bulk up.
Water in and rest. Water once to settle them, then keep on the dry side until growth resumes. Do not feed until leaves are actively growing.

Aftercare

After replanting variable-leaved butterwort, keep the soil barely moist — not wet — until shoots appear; bulbs and tubers rot in cold, saturated soil. Once leaves are growing strongly, resume normal watering. Hold off feeding until the plant is in active growth again.

The right soil mix for variable-leaved butterwort

Variable-Leaved Butterwort wants very free-draining mineral mix, nutrient-poor. Use a mix of equal parts coarse perlite, coarse sand, and a small amount of peat. The substrate must drain almost instantly; standing water around the winter bulb is fatal. Some growers pot the bulb in near-pure perlite or pumice for the dormant period. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting variable-leaved butterwort — frequently asked questions

How often should you repot variable-leaved butterwort?

Lift and divide every 3–4 years once clumps congest for variable-leaved butterwort. Variable-Leaved Butterwort is lifted and divided, not "repotted". Every 3–4 years, once the foliage has died back and it is dormant, lift the clump, separate the offsets, and replant at the correct depth in very free-draining mineral mix, nutrient-poor. Crowding, not pot size, is what reduces flowering over time.

What size pot does variable-leaved butterwort need?

When is the best time of year to repot variable-leaved butterwort?

Do you "repot" variable-leaved butterwort, or lift and divide it?

You lift and divide it. Variable-Leaved Butterwort grows from bulbs or tubers, so instead of repotting you wait for dormancy, lift the congested clump, separate the healthy offsets, and replant them at the right depth and spacing. Doing this every 3–4 years restores flowering.

Should you fertilise variable-leaved butterwort after repotting?

Hold off feeding variable-leaved butterwort until it is in active growth again. Fresh soil already carries enough nutrients to get it re-established, and feeding disturbed roots too soon does more harm than good.