How to overwinter geraniums

Demonstrated by David Domoney. This guide draws on the "How to Overwinter Geraniums" video by David Domoney. David is a well-known UK TV gardening presenter who has appeared on BBC One and ITV, and his channel covers practical gardening topics for UK conditions throughout the year. The video covers both storage methods and the cuttings approach clearly.

1. Hardy cranesbill or tender pelargonium - know which you have

Hardy geraniums (the true Geranium species - cranesbills) are fully winter-hardy in the UK and don't need any special treatment. They die back in autumn and reappear in spring. Leave them be, or cut them back tidily if you prefer a neater border through winter. Job done.

Pelargoniums are the ones that need attention. These are the bright-flowered plants commonly sold as "geraniums" for summer bedding, containers, and hanging baskets. They're frost-tender and will be killed by a hard freeze. Anything with that characteristic slightly pungent scent when you brush the leaves is very likely a pelargonium.

2. Act before the first frost - don't wait

Keep an eye on the forecast from mid-October. In East Kent, the first ground frost typically arrives sometime in October or November, but it varies year to year. The moment overnight temperatures look like dropping below 2°C, bring your pelargoniums in. Frost-damaged stems go black and mushy very quickly, and a badly frosted plant is rarely worth trying to save.

If the plants are in pots, moving them is straightforward. For those planted in the border or in hanging baskets, pot them up into a container before bringing them in.

3. Cut the plants back before storing

Reduce each plant by about half to two-thirds before you store it. Remove any dead or yellowing leaves, finished flower stems, and any growth that looks leggy or weak. The aim is a compact, tidy plant that won't take up too much space through winter.

Check the stems carefully for any sign of disease - grey mould (botrytis) in particular can spread quickly in a winter storage situation. Remove any affected material and make sure the remaining stems look firm and healthy.

4. Take cuttings in August as insurance

Taking a few cuttings in August before you start thinking about overwintering is a sensible habit. Cut a 10 cm length of non-flowering stem, remove the lower leaves, and push the cutting into a small pot of gritty compost. Keep somewhere light and frost-free. These will root quickly and, even if the parent plant doesn't make it through winter, you'll have young plants ready for the following summer.

Cuttings also tend to flower more freely than old, woody specimens - many gardeners replace their pelargoniums from cuttings every year rather than trying to carry the originals over.

5. Store frost-free over winter

Pelargoniums need to stay above about 5°C through winter - cold but frost-free. A cool but bright windowsill, an unheated conservatory, or a frost-free greenhouse all work well. A frost-free garage or shed can work too, though the darker the storage, the more the plants will suffer.

Water very sparingly - just enough to stop the compost drying out completely. Overwatering in winter is one of the most common ways to lose them. A small amount every couple of weeks is usually enough. Don't feed during this dormant period.

6. Bring them back to life in spring

From late February or March, start watering more generously and move the plants to a brighter, slightly warmer spot. New growth should appear quickly. Once the plants are growing actively, start a monthly liquid feed with a balanced fertiliser, then switch to a higher-potassium feed once they start to flower.

Don't rush them outside. Wait until the risk of frost has passed - late April or May in East Kent - and harden them off for a week or two first by putting them outside during the day and bringing them back in at night.

When to call a handyman

Overwintering plants is firmly in the gardener's own territory, but if the end of the season means a general garden tidy - clearing borders, emptying and storing containers, cutting back spent growth - that's something Richard can help with. A thorough autumn tidy makes spring a lot more pleasant.