Overwintering Pelargoniums: How to Keep Your Plants Thriving Through Winter

Introduction

Overwintering pelargoniums is essential to protect these tender perennials from frost and ensure they bloom beautifully again next year. Pelargoniums, often confused with geraniums, are more sensitive to cold and require special care to survive the winter months.

Instead of letting frost kill your pelargoniums, you can store them indoors, keep them in a greenhouse, or use protective coverings to keep them healthy for the next growing season.

In this comprehensive guide, we’ll cover:
✅ The best methods for overwintering pelargoniums
✅ How to store pelargoniums indoors or in a greenhouse
✅ The right way to prune and prepare plants for winter
✅ Common mistakes to avoid
✅ Expert tips for strong regrowth in spring

Why Overwinter Pelargoniums?

Pelargoniums (often called tender geraniums) cannot survive UK winters outdoors unless properly protected. By overwintering them, you can:
🌱 Save money by keeping the same plants year after year.
🌸 Enjoy bigger, healthier blooms in spring.
❄️ Prevent frost damage and avoid replanting new ones every season.

💡 Tip: If temperatures in your area drop below 5°C (41°F), your pelargoniums need protection over winter.

Best Methods for Overwintering Pelargoniums

1. Keeping Pelargoniums as Houseplants (Best for Potted Plants)

✅ Step 1: Bring Pelargoniums Indoors Before Frost

• Move plants inside before temperatures drop below 5°C (41°F).
• Keep in a bright, cool spot (10-15°C / 50-60°F), like a windowsill, conservatory, or porch.

✅ Step 2: Reduce Watering

• Water only when the soil is completely dry to prevent rot.
• Avoid overwatering, as pelargoniums need minimal moisture in winter.

✅ Step 3: Trim Back Growth

• Cut back one-third of the plant to prevent legginess and encourage compact growth.

💡 Tip: Keep pelargoniums near a south-facing window or use LED grow lights if they don’t get enough natural light.

2. Storing Pelargoniums Dormant (Best for Bare-Root Storage)

✅ Step 1: Lift the Plants Before the First Frost

• Gently dig up pelargoniums, shaking off excess soil.

✅ Step 2: Trim & Dry the Plants

• Cut stems down to 10-15 cm (4-6 inches).
• Leave plants to air dry for 24-48 hours in a cool, dry space.

✅ Step 3: Store in a Cool, Dark Place

• Hang upside down or place in a box lined with newspaper.
• Keep at 5-10°C (41-50°F) in a garage, basement, or shed.
• Check monthly for rot or shriveling, misting lightly if too dry.

💡 Tip: Replant dormant pelargoniums in March-April, watering them well to encourage new growth.

3. Overwintering Pelargoniums in a Greenhouse (Best for Large Plants)

✅ Step 1: Move Potted Pelargoniums to a Greenhouse

• A heated greenhouse is ideal, but an unheated greenhouse needs extra insulation.

✅ Step 2: Trim Back Growth

• Cut plants back to half their size to reduce stress.

✅ Step 3: Water Occasionally

• Water only once a month to prevent dehydration.
• Avoid overwatering—cold, damp soil can cause root rot.

✅ Step 4: Insulate in Freezing Weather

• Use bubble wrap, fleece, or straw around pots to protect roots.

💡 Tip: If temperatures drop below freezing (-2°C or lower), use a small greenhouse heater or move pelargoniums indoors.

When to Bring Pelargoniums Back Outside in Spring

✅ Late March – Early April: Begin watering more frequently to encourage new growth.
✅ April – May: Move plants outdoors gradually to harden them off.
✅ After the last frost (typically May): Transplant into borders, containers, or hanging baskets.

💡 Tip: Apply a balanced liquid fertilizer after planting for healthy foliage and abundant blooms.

Common Mistakes to Avoid When Overwintering Pelargoniums

🚫 Bringing plants inside too late – Always move them before frost arrives.
🚫 Overwatering dormant pelargoniums – Causes root rot and fungal diseases.
🚫 Keeping them in a too-warm space – Overwintered plants need a cool but frost-free environment.
🚫 Forgetting to check stored plants – Inspect monthly for mold, shriveling, or decay.

💡 Tip: If leaves turn yellow, your pelargoniums are getting too much moisture or not enough light—adjust care accordingly.

Final Tips for Successful Overwintering

🌡 Monitor temperatures – Keep plants in the correct overwintering conditions.
🏡 Choose the right method – Some pelargoniums need indoor storage, while others can survive in a greenhouse.
💦 Water less frequently – Most overwintering pelargoniums need minimal moisture.
🌞 Give light where needed – Houseplants still need bright, indirect light.
🌱 Check plants monthly – Prevent rot, mold, or dehydration.

💡 Tip: In spring, gradually reintroduce pelargoniums to outdoor conditions to avoid transplant shock.

Conclusion

Overwintering pelargoniums is a simple yet effective way to keep your plants thriving for years to come.

By bringing them indoors, storing them dormant, or using a greenhouse, you can protect pelargoniums from frost and enjoy stronger, healthier plants in spring.

Whether you grow them in pots, beds, or hanging baskets, following these overwintering techniques will ensure successful regrowth and vibrant blooms!