As the seasons change, gardeners often ponder the fate of their beloved plants, especially those as vibrant and diverse as Coleus. Originating from tropical climates, Coleus are celebrated for their stunning, colourful foliage, making them a popular choice in UK gardens. However, with the UK’s colder winters, a crucial question arises: Can these tropical beauties survive the chill? This article delves into the nature of these plants and offers practical advice on how to successfully overwinter coleus in the UK.

Red and Bright Green Coleus UK
Affiliate Disclosure

What Are Coleus?

Coleus, scientifically known as Plectranthus scutellarioides, are renowned for their bright, variegated leaves. These plants are a staple in ornamental gardening due to their wide range of leaf colours and patterns. Originating from tropical regions, they are generally used as annuals in cooler climates but can be perennial in their native tropical environments.

Can Coleus Survive Outside in Winter in the UK?

The simple answer is no. Coleus are not frost-hardy and cannot survive the cold winter temperatures of the UK if left outside. Their tropical nature makes them susceptible to damage from frost and freezing temperatures.

How to Overwinter Coleus Indoors

If your coleus is already potted, you can skip to step 3. If, however, your coleus is in the ground, you will need to do the following:

  1. Dig Up: Before the first frost, carefully dig up your Coleus plants, trying to keep the root ball intact.
  2. Transplant: Transplant them into pots with well-draining soil and place them in a bright sheltered spot outside for around 7 days to help acclimatise and prevent shock.
  3. Bring them Inside: Place them in a bright, indoor area. Ensure they get enough light, preferably from a south-facing window, to maintain their vibrant colours.
  4. Temperature and Care: Keep the indoor temperature consistent and above 10°C (50°F). Water the plants moderately, allowing the soil to dry out slightly between waterings. Avoid overwatering to prevent root rot.
  5. Pruning: Prune the Coleus to encourage bushier growth. This will help them stay compact and attractive throughout the winter.

How to Propagate Coleus from Cuttings

Coleus can easily be propagated from cuttings so that is also an option if you don’t have space for a large parent plant:

  1. Taking Cuttings: As an alternative or in addition to bringing plants indoors, you can propagate Coleus by cuttings. Snip off healthy stems about 10-15 cm (4-6 inches) long, removing the lower leaves.
  2. Rooting the Cuttings: Place the cuttings in a jar of water or plant them in a pot with moist potting soil. Keep them in a bright location but out of direct sunlight.
  3. Transplanting: Once the cuttings have rooted and grown sufficiently, usually in a few weeks, they can be transplanted into individual pots.

Monitoring and Maintenance

  • Monitor Plant Health: Throughout the winter, keep an eye on your Coleus for signs of stress, such as drooping leaves or discolouration.
  • Pest Control: Be vigilant about pests that can thrive in indoor conditions, like spider mites or aphids. Regularly inspect the leaves and stems and treat promptly if pests are found.

Transitioning Back Outdoors

  • Gradual Acclimatisation: As spring approaches and temperatures rise, gradually acclimate your Coleus to outdoor conditions. Start by placing them outside for a few hours each day in a shaded area, gradually increasing their exposure to the outdoors over a week or two.
  • Avoiding Shock: Be mindful of temperature fluctuations and avoid placing the Coleus outside on particularly cold nights.

Conclusion

Overwintering Coleus in the UK requires a bit of effort because they will not survive outside in the UK through the winter, but it’s a rewarding task. By understanding their tropical nature and providing appropriate care, you can enjoy the vivid beauty of Coleus throughout the year. Whether you choose to bring them indoors or propagate new plants through cuttings, these methods ensure your Coleus remain a vibrant part of your garden season after season.

How To Propagate Coleus from Cuttings Infographic
How To Propagate Coleus from Cuttings Infographic

Garden Doctor Tips

“Bring your coleus indoors before the first frost to protect them from cold temperatures. Place them in a bright area where they receive indirect sunlight to maintain their vibrant colours!”

“Reduce watering in the winter months, allowing the soil to dry out slightly between waterings. Overwatering can lead to root rot, which is detrimental during colder months!”

“Consider taking cuttings from your coleus to propagate new plants. This not only ensures you have new plants for the next season but also helps in preserving the genetics of particularly beautiful varieties!”

“Prune your indoor coleus regularly to encourage bushy, compact growth. This helps prevent them from becoming leggy and maintains their aesthetic appeal throughout winter!”

Frequently Asked Questions

How do you keep coleus over winter in the UK?

Bring coleus indoors before the first frost. Keep them in a bright, warm area, ensuring they receive enough light and are protected from cold temperatures.

Can coleus stay outside in winter?

No, coleus cannot survive outside in the UK winter as they are not frost-hardy.

Are coleus hardy in the UK?

Coleus are not hardy in the UK’s cold winter conditions and require protection or indoor overwintering.

What is the coldest temperature coleus can tolerate?

Coleus can tolerate temperatures down to about 10°C (50°F) but prefer warmer conditions.

What temperature kills coleus?

Temperatures below 10°C (50°F) can be harmful to coleus, with frost and freezing temperatures being potentially lethal.

Do coleus do better inside or outside?

Coleus thrive outside in warm, frost-free conditions but do better inside during cold or frost-prone periods.

Where is the best place to keep a coleus plant?

The best place for a coleus plant is a bright spot with indirect sunlight, protected from strong winds and extreme temperatures.

How long do coleus plants live for?

Coleus are typically treated as annuals but can live for several years if protected from cold temperatures and properly cared for.


Author

Trevor Wright is not just a seasoned horticulturist; he’s the esteemed Garden Doctor. With a BSc in Horticulture and years of hands-on experience in the soil, Trevor has become a trusted mentor for all things gardening. As the founder of Garden Doctor, he’s committed to clarifying the intricacies of gardening, offering straightforward advice that’s rooted in years of practice. His writing is a garden of how-tos, savvy insights, and comprehensive guides that enable individuals to nurture and grow their garden dreams. When he’s not knee-deep in garden beds, Trevor is at his keyboard passing on his green-thumbed wisdom to budding gardeners, ensuring that the legacy of sustainable and joyful gardening blossoms far and wide.


More You Might Like