Best Greenhouses & Cold Frames UK (2026)
Glass, polycarbonate and mini greenhouses for growing in the UK climate.
33 products reviewed in this subcategory
#1 Pick
Palram Canopia Harmony 6x8 Silver Greenhouse, Polycarbonate- Polycarbonate
- Small gardens
- 10 Years
Currently unavailable
Pros
- Shatterproof polycarbonate panels with over 90% light transmission
- Rust-resistant aluminium frame with galvanised steel base
- Sliding door and roof vent for airflow
Cons
- Assembly takes a full weekend for two people
#2 Pick
Selections Wooden Framed Polycarbonate Cold Frame Growhouse- Wood
- Balcony/patio
- 1 Year
£37.98
Pros
- Wooden frame with polycarbonate glazing
- Great for hardening off seedlings
- Compact footprint for patios
Cons
- Not tall enough for mature plants
#3 Pick
Halls Forest Green Supreme 8ft x 6ft Greenhouse, Toughened Glass- Glass
- Large gardens
- 15 Years
Currently unavailable
Pros
- Toughened safety glass throughout
- Smooth-action sliding door and air vent for airflow
- Curved eaves add extra headroom
Cons
- Higher price
- Requires a solid, level base
£19.99
Pros
- Reinforced weatherproof PVC cover
- Roll-up zip door for easy access
- Tool-free assembly, ideal for patios
Cons
- Less sturdy than a full-size greenhouse
- Cover needs replacing after a few seasons
#5 Pick
Outsunny Polytunnel Greenhouse with Windows and Door, 3 x 2m- Plastic
- Large gardens
- 1 Year
£56.99
Pros
- Galvanised steel frame for durability
- Roll-up door and mesh windows for ventilation
- Walk-in height suits full-size crops
Cons
- PE cover less durable than polycarbonate or glass long-term
#6 Pick
Oypla Growbag Tomato Growhouse Garden Greenhouse with PVC Cover, 150x100x50cm- Plastic
- Balcony/patio
- 1 Year
Currently unavailable
Pros
- Sized to fit standard growbags
- Sturdy tubular steel frame with PVC cover
- Roll-up zipped door for ventilation
Cons
- Best suited to patios rather than full-size crops
About greenhouses & cold frames
Bringing the garden indoors – or extending its season considerably – is what greenhouses and cold frames are all about. These structures provide a controlled environment for growing plants, from tender herbs and salads through the winter months to extending the flowering period of your favourite perennials well into autumn. In the UK, with our famously changeable weather, a greenhouse isn’t simply a luxury; it's a practical investment that can significantly boost your harvest and allow you to enjoy gardening year-round. A good quality structure will offer protection from frost, wind, and even heavy rain, creating a microclimate ideal for delicate seedlings or fruiting plants needing extra warmth. When considering a greenhouse or cold frame, the first thing to think about is size – don’t overbuy! Measure your available space carefully, factoring in access for maintenance and movement of plants. A small lean-to greenhouse might be perfect for herbs near a south-facing wall, while a larger freestanding structure will obviously offer more growing capacity.
Before you commit to a purchase, understanding the materials used is crucial. Polycarbonate panels are incredibly popular due to their excellent light transmission and durability, offering good insulation. Glass offers superior light quality but can be heavier and more prone to breakage, particularly in windy areas of the UK. Frame materials range from aluminium (lightweight and rust-resistant) to treated timber which can be a cost-effective option for smaller cold frames. Budget is another key consideration; prices vary dramatically depending on size, material, and features like ventilation and heating options. Remember that initial purchase price isn't the only expense – factor in delivery costs, ground preparation (a level base is essential!), and potentially additional accessories such as shelving or potting benches. Finally, think about seasonal timing. A smaller cold frame is ideal for starting seeds early in spring or extending the harvest of leafy greens late into autumn; a larger greenhouse can accommodate a wider range of plants throughout the year.
One common mistake UK gardeners make when setting up a greenhouse is neglecting ventilation – overheating can be just as damaging as frost! Good airflow is vital to prevent fungal diseases and maintain healthy plant growth, so ensure your chosen model has adequate vents or doors. Another frequent oversight is insufficient ground preparation; a level, well-drained base will improve stability and drainage. Also, don’t underestimate the importance of location – south-facing sites are ideal for maximising sunlight exposure, but consider prevailing winds and potential obstructions. A greenhouse seamlessly integrates into your home and garden, providing both practical functionality and aesthetic appeal. It's an extension of your outdoor space, offering a dedicated area for nurturing plants and creating a tranquil retreat.
Ultimately, investing in a greenhouse or cold frame is about expanding your gardening possibilities within the UK climate. With careful planning, choosing the right size and materials, and addressing potential pitfalls like ventilation and drainage, you can create a thriving horticultural haven that brings enjoyment and fresh produce to your home for years to come.
Where to go next
FAQ
What size greenhouse should I buy?
Consider the plants you want to grow – herbs need smaller frames, while tomatoes and peppers require considerably more space. A small lean-to greenhouse might be suitable for beginners, whereas a larger polytunnel is better for serious gardeners wanting to extend their growing season.
What materials are greenhouses made from?
Most affordable options are plastic (polycarbonate or polyethylene) which offer good light transmission but may require more frequent replacement. Glass greenhouses provide superior insulation and aesthetic appeal, though they're generally more expensive and heavier.
How much do greenhouses typically cost?
Prices vary greatly; basic polytunnels can start from around £150, while professional-grade polycarbonate greenhouses range from £800 to upwards of £5000 depending on size and features. Factor in accessories like shelving and heating too.
How much maintenance do greenhouses need?
Regular cleaning with soapy water is crucial to maintain light transmission. Check for leaks, especially around seams and glazing panels, and ensure adequate ventilation to prevent condensation build-up.
Are there any regulations regarding greenhouse construction?
Check your local planning permission requirements – many smaller greenhouses are exempt, but larger structures or those affecting neighbours' views might need approval. Always adhere to building codes for safety.
What’s the best time of year to buy a greenhouse?
Autumn and winter are often quieter periods with better deals on end-of-season stock, ideal if you’re planning an early start next spring. Summer sales also offer discounts but selection may be limited.
How do I protect my plants from frost in a cold frame?
Cold frames can be insulated with bubble wrap or horticultural fleece to retain heat and protect tender seedlings from freezing temperatures. Regularly vent during the day to prevent excessive humidity.
What's a common mistake beginners make with greenhouses?
Overheating is a frequent issue, leading to plant stress and disease. Ensure adequate ventilation and consider shading options during the hottest parts of the day.
Can I use a greenhouse for winter growing?
Absolutely – with supplemental heating (electric heaters or thermostats) and careful monitoring of temperature and humidity, you can successfully grow vegetables and herbs throughout the colder months.
What's the best way to secure my greenhouse?
A robust base is essential; gravel foundations offer drainage and stability. Consider anchoring larger frames with ground stakes for added security against strong winds.