Winter Sleep: How to overwinter your plants like a pro

As frosts creep across the lawn and the air sharpens with the promise of winter, many gardens begin to fall quiet. But just because the growing season slows, it doesn’t mean the work stops. In fact, now is the moment to protect your plants from the chill and give them the best chance to thrive again next spring. This is the art of overwintering. Helping vulnerable plants survive cold weather rather than losing them to frost.

What Is Overwintering?

Overwintering simply means keeping tender plants alive through winter by giving them shelter or protection. While hardy shrubs and perennials can cope with freezing weather, other favourites such as geraniums, dahlias, citrus trees, and fuchsias need a little extra help. With a few simple steps, you can enjoy stronger, healthier plants year after year.

Plants That Need Extra Care

Some plants shrug off frost without complaint. Others, not so much. The ones most at risk include:

• Tender perennials like geraniums (pelargoniums) and fuchsias

• Summer-flowering bulbs and tubers such as dahlias, cannas, and begonias

• Mediterranean-style plants including olive trees, lavender, and rosemary

• Citrus trees such as lemon and calamondin, plus other exotics like banana plants

• Houseplants that spent summer outdoors, such as ferns and spider plants

If in doubt, check the label. Anything marked "tender" or "half-hardy" needs attention before the first frost arrives.

How to Overwinter: Step by Step

1. Prepare before the first frost
Don’t wait until plants are damaged by cold. Plan their winter care in late autumn.

2. Move vulnerable plants under cover
Bring pots indoors to a porch, conservatory, unheated spare room or greenhouse. Even a bright windowsill works if space is limited.

3. Cut back and clean
Trim straggly growth and remove any dead or diseased leaves. Check carefully for pests hiding under foliage, you don’t want to invite greenfly or spider mites indoors for winter.

4. Reduce watering
Growth slows dramatically in winter, so roots need far less moisture. Keep compost just barely damp to prevent rot.

5. Protect those left outside
If you can’t bring everything in, wrap pots with fleece or bubble wrap, raise them on pot feet to prevent waterlogging and tuck them against a sheltered wall.

6. Store bulbs and tubers
Plants like dahlias and begonias should be lifted after the first frost blackens their leaves. Store the tubers in dry compost or paper bags somewhere cool and frost-free.

Overwintering Indoors: Where to Put What

You don’t need a fancy greenhouse to overwinter plants. A cool spare room works beautifully for geraniums and fuchsias, while citrus trees are happiest in a bright but unheated space like a porch or conservatory. Tubers and bulbs don’t even need light, a frost-free shed or garage will do. Wherever you place your plants, avoid warm central heating and aim for steady temperatures between 5–10°C.

Overwintering Do’s and Don’ts

Do:

• Check plants for pests before bringing them inside

• Use fleece or horticultural blankets outdoors

• Mulch around perennials to protect their roots

• Take cuttings if space is tight – they’re easy insurance plants

• Label stored bulbs and tubers for spring planting

Don’t:

• Overwater – winter rot is the number one killer

• Leave terracotta pots exposed to frost – they can crack

• Fertilise plants during dormancy – they need rest, not growth

• Crowd pots together – it encourages mildew

• Panic if leaves drop – many plants shed foliage to save energy

Common Mistakes to Avoid

One of the biggest overwintering mistakes is moving plants straight from the cold outdoors into a warm, centrally heated house. The temperature shock can cause leaf drop and stress. Instead, move them gradually to cooler indoor spaces. Another common slip-up is forgetting about ventilation. Even resting plants need fresh air every now and then to prevent mould.

Final Thought

Overwintering is a little act of hope in the darker months. Instead of treating plants as seasonal throwaways, it encourages us to care, nurture and preserve. With just a bit of preparation now, you’ll greet spring with a garden full of life, colour and familiar favourites ready to bloom again.