How to overwinter geraniums (pelargoniums) in the UK

By Sophie Sparkes · October 2026 · 6 min read

Summer bedding geraniums are frost tender, so the first hard frost turns them to mush. But they are also some of the easiest plants to keep from one year to the next. A plant that cost a few pounds in May can be bigger and better next summer, and it takes very little effort over winter.

Short answer: bring geraniums (pelargoniums) indoors or into a frost-free greenhouse before the first frost, usually October in most of the UK. Either keep them growing on a bright, cool windowsill, or cut them back by about a third to a half and keep them cool and almost dry until March. Water very sparingly all winter, since too much water kills more overwintered geraniums than cold. In spring, give them more light, water and food, then plant out after the last frost.

Which geraniums need bringing in?

There are two quite different plants called geraniums:

• Pelargoniums are the bedding and pot "geraniums" with bright red, pink or white flower heads, including zonal, ivy-leaved and regal types and the scented-leaf kinds. They come from South Africa, are not frost hardy, and need protecting. This guide is about these.
• Hardy geraniums (cranesbills), like 'Rozanne' or 'Johnson's Blue', are border perennials. They die back and return every year without help. Just tidy them up by cutting off the old growth in autumn or early spring.

When to bring them in

Before the first frost. In much of the UK that means some time in October, earlier in the north and in cold, inland gardens, and possibly November in mild coastal and city gardens. Watch the forecast and bring them in when nights are heading towards 3-4°C rather than waiting for the first frost itself. Our guide to protecting plants from frost explains how to read the warning signs.

Three ways to overwinter geraniums

1. Keep them growing indoors

Lift plants from the border, or bring in pots, and pot them into the smallest pot that fits the roots. Pick off yellow leaves and old flowers. Stand them on the brightest, coolest windowsill you have, ideally a room around 10-15°C rather than a warm living room. They may keep flowering a little. Water only when the compost is dry. They will get a bit leggy by spring, which you can fix by cutting back in March.

2. Cut back and keep them dormant

This is the classic gardener's method and saves a lot of space. Cut the stems back by about a third to a half, to just above a leaf joint, and pot the plants up close together. Keep them somewhere frost-free, cool and light, such as a greenhouse kept above freezing, a porch or a cold spare room. Around 5-10°C is ideal. Water just enough to stop the compost drying out completely, perhaps once a month, and keep the leaves dry.

3. The paper bag method

An old trick for when there is no room for pots. Dig up the plants, shake off the soil, cut them back by about half, and put each one in a paper bag, or hang them upside down, in a cool, dark, frost-free place such as a garage that does not freeze. Check them every month or so and, if the stems are shrivelling, soak the roots in water for an hour or two and let them dry before putting them back. It works, but more plants are lost this way than in pots, so use it for spares rather than favourites.

Winter watering and problems

Geraniums store water in their stems and cope with dry conditions far better than wet. In cool, dim winter conditions wet compost leads to rot and grey mould (botrytis): fuzzy grey patches on leaves and stems. To prevent it:

• Water sparingly and only in the morning, onto the compost, not the leaves.
• Pick off dead and yellowing leaves every week or two.
• Give them space and open the greenhouse or window on mild days for fresh air.
• Cut out any stem that turns black and soft, back to healthy green growth.

A few yellow lower leaves are normal in winter. Lots of yellow leaves usually mean too much water. Long, pale, floppy growth means too little light or too much warmth.

Waking them up in spring

From March, as the days lengthen, move the plants somewhere brighter and a little warmer, water more often and start a liquid feed every couple of weeks. Cut leggy stems back by about half to make bushier plants, and pot on any that have filled their pots. Pinch out the tips of new shoots once or twice for more flowers. Harden them off and plant out after the last frost, typically mid-May in mild areas and late May or early June further north.

Geranium questions

Can geraniums survive the winter outside in the UK?

Pelargoniums cannot survive frost, so they will not normally make it through a UK winter outdoors. In the mildest coastal gardens a plant against a sheltered wall may survive a gentle winter, but it is a gamble. Hardy geraniums (cranesbills) stay outside without any problem.

Should I cut back geraniums for winter?

Cut back by about a third to a half if you are keeping them dormant in a greenhouse, porch or cool room. If you are keeping them growing on a bright windowsill, just tidy them up and do the main cut back in March.

How often should I water geraniums in winter?

Very little. Dormant plants need watering perhaps once a month, just enough to stop the compost going bone dry. Plants growing on a windowsill need water only when the compost is dry to the touch.

Can I keep geraniums in the garage over winter?

Yes, if it stays above freezing. A dark garage suits the paper bag method or cut-back plants that are fully dormant. If there is a window, potted plants will do better.

Are geraniums toxic to cats and dogs?

Yes, pelargoniums are listed as toxic to cats and dogs. Chewing the leaves can cause vomiting, loss of appetite and skin irritation, so keep plants you bring indoors out of reach of pets that chew.