The Art of Overwintering Geraniums

Geraniums, beloved for their continuous bloom and vibrant colours, often pose questions about their care, especially when winter is around the corner. With the right knowledge, these plants can be nurtured year after year, providing endless beauty to gardens and homes. We have a whole section about overwintering plants once you have finished here!

Can you leave geraniums in pots over winter?

Indeed, geraniums can spend the winter in their pots. If they’re container-grown, relocating them to a frost-free, sheltered location like a garage, shed, or even a cool room inside your house can be beneficial. While they’re in their winter spot, ensure they receive indirect sunlight to keep them healthy but in a state of dormancy.

How do I save my geraniums for next year?

To ensure your geraniums are ready to shine the following year, it’s crucial to protect them from frost and severe cold. As temperatures drop, consider relocating your geraniums to a warmer spot. Regularly inspect for pests and diseases, removing any affected parts to keep the plant healthy. Water sparingly, as geraniums in dormancy require less moisture.

What are 4 easy ways to overwinter geraniums?

  1. Indoor Houseplants: Transition your geraniums indoors, placing them near windows that receive bright but indirect light.
  2. Propagation via Cuttings: Take healthy cuttings from your geraniums and root them in pots indoors, offering a fresh start for the next season.
  3. Cool Storage: Find a cool, frost-free spot like a basement where the geraniums can rest without freezing.
  4. Dormant Bare Root Storage: Gently remove geraniums from their pots, shake off excess soil, and store them in a dry, cool place, like a paper bag in a basement.

How do you prune geraniums in pots for winter?

When autumn rolls around and you’re preparing your geraniums for their winter rest, prune them. Cutting back the plants to about 10cm from the soil’s surface helps promote better growth in the spring. This pruning also prevents leggy growth and encourages more robust, bushier plants.

Can you overwinter geraniums in a garage?

A garage can be an ideal winter home for geraniums, especially if it remains frost-free. When placing your geraniums in the garage, ensure they’re away from direct sunlight but still in a well-ventilated area. Come spring, with some pruning, watering, and TLC, they’ll be rejuvenated and ready to bloom.

How do you overwinter geraniums UK?

In the UK’s temperate climate, the primary concern for geraniums is frost. Before the first frost hits, move your geraniums to a frost-free location, whether it’s indoors, in a greenhouse, or a sheltered part of the garden. Regularly check for pests and ensure they receive adequate light.

What month do you cut back geraniums?

For perennial geraniums, the best time to prune is post-bloom, which often falls between August and late October. This pruning not only prepares them for the dormant winter period but also energizes them, ensuring a burst of growth in the spring.

Can you overwinter geraniums in an unheated greenhouse?

Using a greenhouse is an excellent method for overwintering geraniums. While they only need to be kept frost-free, it’s often recommended to use a heater to ensure temperatures stay above freezing, ideally around 5°C or 41°F. This protection ensures the stems and leaves remain healthy, ready for the next season.

How do you take care of geraniums outside in pots?

When caring for outdoor potted geraniums, ensure they’re placed in a location where they receive ample sunlight. Water them when the top inch of soil feels dry, and ensure the pots have good drainage to prevent waterlogging. Regularly deadhead spent blooms to encourage more flowering.

How do you keep geraniums blooming inside in the winter?

To promote indoor winter blooming, place geraniums near a bright, south-facing window. Water them sparingly, allowing the soil to dry out between watering. Ensure the room has good humidity, and consider using a general-purpose fertilizer once a month.

Does geraniums grow back every year?

Yes, geraniums are perennials, meaning they can return year after year. They thrive in both sun and partial shade and adapt well to various soil conditions. With minimal maintenance, they’ll continue to bloom annually, showcasing their vibrant colors.

How do you cut back geraniums?

Regularly prune your geraniums by removing dead or yellowing leaves and spent blooms. This not only keeps the plant looking fresh but also encourages new growth and more blooms.

Do you have to winterise geraniums?

Winterising geraniums gives them a head start for the next blooming season. Whether you’re storing them in a dormant state or treating them as houseplants, a little winter care can lead to vibrant blooms come spring.

What to do with geraniums after flowering?

Once geraniums have finished blooming, it’s time to deadhead. Remove the spent flowers to encourage more blooms and ensure the plant’s energy isn’t wasted on seed production.

What is the lowest temperature that geraniums can tolerate?

While geraniums are quite hardy, they thrive best with night temperatures between 50° to 60°F (10° to 16°C). They can endure temperatures as low as 32°F (0°C) and highs of 80°F (27°C) if kept relatively dry.

How long do geraniums last in pots?

With proper care, geraniums can thrive in pots for many years, even decades. Their adaptability makes them one of the few species that often do better in containers than directly in the ground.


Geraniums, with their brilliant hues and hardy nature, are a treasure in any garden. By understanding their needs, especially during the colder months, you can ensure these floral wonders continue to grace your space with their beauty year after year.

Steps to Overwinter Geraniums in an Unheated Greenhouse:

  1. Insulation: Consider insulating the greenhouse with bubble wrap. This can provide an additional layer of protection, trapping air and creating a barrier against the cold.
  2. Positioning: Place geraniums in the center of the greenhouse, away from the glass, as this area tends to be warmer.
  3. Monitoring Temperature: Invest in a max-min thermometer to keep track of the temperatures inside the greenhouse. This will help you know if and when you need to take additional measures to protect your plants.
  4. Ventilation: On milder days, ensure the greenhouse is ventilated to prevent mold and mildew growth. This can be achieved by opening the door or vents for a short period.
  5. Watering: Water sparingly. Overwintering plants need less water, and overwatering can lead to root rot. Only water when the soil is dry to the touch.
  6. Check for Pests: Before moving your geraniums into the greenhouse, check for pests and diseases. An enclosed environment can exacerbate any infestations.
  7. Heating: If temperatures are forecasted to plummet, consider using an electric fan heater on the coldest nights. While the goal is not to make the greenhouse warm, it can help in keeping it just above freezing.
  8. Frost Cloth or Fleece: Covering your geraniums with horticultural fleece or frost cloth on exceptionally cold nights can offer an extra layer of protection.
  9. Check Plant Health: Regularly inspect your geraniums for signs of stress, disease, or pest infestations and take action if needed.

By taking these precautions and being proactive in your care, you can successfully overwinter geraniums in an unheated greenhouse and enjoy their vibrant blooms year after year.


Q and A

Can I crop this down and have it recover? A: It’s worth a try, but it’s advisable to wait until spring before doing so.

Should I prune the plants now, or let them grow until spring? A: It’s suggested to let the plants grow until spring before trimming them back.

When instructions are to prune back to healthy growth, is that green or stem? A: Prune back to just above a healthy set of leaves ensuring the stem is green with no signs of damage or disease.

 Is the leaf loss a normal winter thing or is it something I’ve done/not done? A: The leaf loss may be due to cold and wet conditions; letting them dry out and cutting them back to healthy growth in spring might help.


Last Modified: October 16, 2023