Do Mexican Butterworts Need Dormancy? The Winter Rosette Explained

Every winter we get the same message: the leaves have gone small and tight, they are not sticky any more, and the plant has stopped catching anything. Something is wrong.

Almost always, nothing is wrong. Here is what is actually happening, and the short answer to the question in the title: Mexican Pinguicula do not require a cold dormancy the way a Venus flytrap does — but most of them will shift into a winter form anyway, and how you water them through it decides whether they survive.

What is actually happening

Most Mexican Pinguicula are heterophyllous, which means they grow two entirely different kinds of leaf depending on the season.

Through spring and summer the plant produces broad, flat, glistening carnivorous leaves covered in sticky mucilage. As the days shorten and nights cool, it stops making those and instead produces a tight rosette of small, thick, succulent leaves with no glands at all. The plant is not sick, and it is not dying back — it has swapped one kind of leaf for another.

The practical consequence is that a plant in its winter rosette is not carnivorous. It will not catch fungus gnats during this phase, and it does not need to eat. Dew production returns with the spring growth cycle.

Required, or just triggered?

This is where Mexican butterworts differ from the carnivorous plants people usually compare them to. A Venus flytrap or a temperate sundew genuinely needs a cold winter rest, and skipping it will exhaust the plant over a couple of seasons.

Mexican Pinguicula do not carry that requirement. The winter rosette is a response to conditions rather than a biological necessity, which is why a plant kept warm and brightly lit year-round may never form one and will be perfectly healthy. It is triggered, not required.

That said, we do not recommend fighting it. If your plant is heading into its winter form, let it — trying to force continuous growth with heat and light is more likely to stress the plant than to help it.

What triggers the switch

Two things, working together: shorter days and cooler nighttime temperatures, roughly in the 50 to 60°F range. Indoor growers can bring it on deliberately by reducing light hours and moving plants to a cooler room, and can largely avoid it by keeping plants warm under a consistent light schedule.

Because the trigger is environmental rather than a fixed calendar, timing varies. A plant on a cool windowsill may shift in October; the same cultivar under lights in a heated room may hold its summer leaves into January or skip the change entirely.

How to water a resting plant

This is the part that actually matters, and the one place people lose plants.

A winter rosette is essentially a succulent, and it is using very little water. Overwatering a resting plant is the easiest way to lose one. Cut back hard: a light watering every 10 to 14 days is usually plenty, or simply water when the mix has gone fully dry.

Everything else stays the same. Still distilled, rain, or reverse-osmosis water only — never tap. Still no fertiliser. Keep the plant in good light; the winter form still photosynthesises even though it has stopped trapping insects.

What our plants actually do

Behaviour varies by cultivar, and it is worth knowing what to expect from the specific plant you own.

Plant	Winter behaviour
P. gigantea × moctezumae	No winter rosette at all. Stays leafy year-round, simply slows down
'Pirouette'	Optional. Grows straight through winter if kept warm
'Johanna'	May form a succulent rosette with smaller, tight leaves
'Weser'	Expect a succulent phase with smaller, tighter leaves
'Sakurahime'	May form a succulent rosette
'Aphrodite'	Shifts to a compact succulent phase with smaller leaves
agnata 'El Lobo'	Reliably forms a tight succulent rosette until spring
P. debbertiana	Tight succulent rosette; the most particular about a proper dry rest
Drosera capensis 'Red'	Not a Pinguicula. No dormancy needed — see the Cape sundew guide

As a rule, the vigorous hybrids are relaxed about it and the species and locality forms are stricter. P. debbertiana in particular wants a genuinely dry winter rest, and is the one plant on this list where getting it wrong is likely to cost you the plant.

If your plant arrives in winter form

Orders placed in autumn or winter often arrive as a compact, non-sticky rosette. That is a healthy resting plant, not a damaged one. Pot it up exactly as you would any other, keep it bright, water it sparingly, and the sticky spring leaves will follow in their own time.

This is also, incidentally, the best moment to take leaf pullings — winter succulent leaves root far more reliably than summer carnivorous ones.

Coming out of it

As days lengthen and temperatures rise, the plant starts pushing broader leaves from the centre of the rosette. Once you see the first genuinely sticky leaf, resume normal watering: water when the top of the mix feels dry, either lightly from above or by standing the pot in a shallow tray for 15 to 30 minutes and then draining it.

Many Mexican Pinguicula flower on the way out of the winter rosette, so a flower stalk in late winter or early spring is a good sign rather than a stress response.

Common questions

My butterwort's leaves are small and not sticky. Is it dying?

Almost certainly not. That is the winter rosette — the plant's non-carnivorous cold-season form. Reduce watering sharply, keep it in good light, and wait for spring.

Do I need to put it somewhere cold?

No. Mexican Pinguicula do not require a cold rest, unlike Venus flytraps and temperate sundews. Cool nights will trigger the winter form, but nothing bad happens if the plant never gets them.

Should I keep feeding it during winter?

No. The winter rosette has no glands and cannot digest anything. Do not attempt to feed it, and never add fertiliser to the soil.

How long does the winter phase last?

Typically a few months, ending as days lengthen. It varies with your conditions rather than the calendar — a plant under lights in a warm room may have a very short rest or none at all.

Can I prevent it entirely?

Often, yes, by keeping the plant warm with a consistent light schedule — 'Pirouette' in particular will grow year-round in those conditions. We would not force it, though: if a plant is heading into its winter form, letting it go is the lower-risk option.

Should I remove the dead summer leaves?

You can gently remove leaves that have fully dried, but there is no need to tidy the plant. Never pull at anything still attached to the crown — if a leaf resists, leave it.

Where to go next

The full year-round routine is in our Mexican Pinguicula care guide. If you are choosing a plant and would rather avoid the winter shift altogether, our first-butterwort guide notes which cultivars stay leafy.

Shop Mexican Pinguicula →