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Cold frames

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cold frame gardening

Buy a cold frame for vulnerable seedlings

Protect young plants and extend your growing season with our high-quality cold frames. Built with corrosion-resistant aluminium frames and twin-wall polycarbonate panels, our cold frames create a sheltered microclimate that helps vulnerable seedlings establish strong roots before being exposed to outdoor conditions. Ideal for early sowing, hardening off, and frost protection, they are a practical addition to any garden.

A cold frame built to last

Our cold frames are designed for long-term use, offering a durable and cost-effective solution for gardeners who want reliable plant protection year after year. Robust aluminium frames combined with insulating polycarbonate panels ensure stability, weather resistance, and consistent performance across the seasons. Suitable for both experienced gardeners and beginners, cold frames provide dependable growing conditions without the complexity of a greenhouse.

What is a cold frame?

Gardening with a cold frame allows you to grow a wider range of plants and improve yields by protecting young crops during vulnerable stages. Our standalone cold frames offer generous interior space, with approximately 33 cm of clearance at the front and up to 44 cm at the rear, providing room for healthy plant development. They are well suited for early-season planting, overwintering hardy vegetables, and supporting heat-loving crops during cooler periods of the year.

open cold frame

Gardening with a cold frame

Cold frame gardening can help you increase your yields and explore more plant varieties, including tender plants like eggplants and chilies. Our standalone cold frames offer ample space and protection for young crops to grow, providing 33 cm of clearance at the front and 44 cm at the rear. This makes them perfect for nurturing young plants and overwintering hardy vegetables, ensuring they thrive in various weather conditions.

planting cold frame

What to grow in a cold frame

Cold frames are highly versatile and support a wide range of plants throughout the year. They are ideal for overwintering young annuals, protecting alpines from excessive winter rain, and giving early crops such as spinach, radishes, lettuce or peas a head start. In spring, cold frames are commonly used to harden off seedlings before transplanting outdoors. Heat-loving plants such as tomatoes, aubergines, and chillies can also benefit from early growth in a cold frame during cooler months or transitional seasons.

Hardening off seedlings in a cold frame

Hardening off seedlings in a cold frame allows plants to gradually adjust to outdoor conditions before planting out. This process typically takes around two to three weeks, during which seedlings are exposed to cooler temperatures, increased sunlight, and gentle air movement. During colder nights, additional protection such as horticultural fleece or blankets can be placed over the cold frame to prevent frost damage.

    Four helpful tips for using a cold frame

    • Temperature Monitoring

      Check the internal temperature regularly using a thermometer. This helps ensure conditions remain suitable for the plants you are growing and prevents heat stress on sunny days.

    • Ventilation

      Ventilation is essential to avoid overheating. Open the lid partially on warm days and close it again in the evening to retain warmth. Adjustable lid openings allow for controlled airflow.

    • Watering Strategy

      Cold frames reduce exposure to natural rainfall, so plants may require more consistent watering. Ensure the soil drains well to prevent waterlogging and root problems.

    • Seasonal Adaptation

      Cold frames can be used year-round when adapted to seasonal needs. Start seeds early in spring, protect plants from excess heat in summer, extend harvests in autumn, and shelter frost-tolerant crops in winter.

    The best materials for a cold frame

    Our cold frame covers are crafted from high-grade aluminium and twin-wall polycarbonate sheets, which ensure long-life protection and insulation for your plants.

    Twin-wall polycarbonate cold frames

    Our professional garden greenhouse cold frame has a polycarbonate cover and walls. This lightweight, hard-wearing material has excellent properties that meet the requirements of growing both tender and half-hardy plants:

    • Thermal Insulation

      The polycarbonate panels provide thermal insulation, maintaining a stable and warm environment for plants during colder months, ensuring their growth and survival.

    • UV Protection

      The polycarbonate material effectively filters harmful UV rays, protecting the plants from potential sun damage while still allowing them to thrive under natural light.

    • Light Transmission

      The 16-mm-thick twin-walled polycarbonate panels allow optimal light transmission. This ensures that plants receive adequate sunlight for photosynthesis, promoting healthy growth.

    Strong and lightweight aluminium frames

    The aluminium used in our cold frames boasts exceptional durability, providing a sturdy foundation for long-lasting structures. Its corrosion-resistant properties make it an ideal choice for metal cold frames, ensuring longevity in various weather conditions. Crafted with precision, our aluminium cold frames offer robust support while maintaining a sleek and lightweight design for ease of use.

    aluminium cold frame

    Comparison of various cold frame materials

    Woodern cold frame with glass coverAluminium cold frame with polycarbonate panels
    Natural material
    		Durable and weather-resistant
    Rustic look
    		Clean modern appearance
    Not weather-resistant
    		Lightweight and easy to handle
    Bulky timber frame
    		Easy access with hinged lids
    Needs care & maintenance
    		10 year guarantee on the polycarbonate sheets

    How to build a cold frame

    DIY cold frames are popular among hobby gardeners and are often made from wood or reclaimed windows. While this approach can be cost-effective, these materials typically require more maintenance and may not offer the same durability or insulation as modern designs. Our polycarbonate cold frames are supplied as complete kits with pre-fitted components, allowing for straightforward assembly and long-term protection for your plants.

    Our cold frame sizes

    small cold frame
    medium-sized cold frame
    large cold frame

    Our standalone cold frames are available in various widths to suit different needs. Our smallest cold frame, the DORIS 1010, starts at approximately 103 x 103 cm and features 2 openable lids with handy stands, enabling you to control the temperature on warm days. For wider options, we offer the DORIS 1910 with a width of approximately 197 x 132 cm, and the DORIS 2010 with a width of approximately 205 x 103 cm. These larger models feature lids on either side, allowing you free access to tend to your plants. The CARO 1013, measuring approximately 103 x 132 cm, and the CARO 2013, measuring approximately 205 x 132 cm, extend to a depth of approximately 132 cm, providing ample space for your gardening needs. With such a big range of products, you're guaranteed to find a size that suits your garden.

    Raised bed covers

    Exlpore our assoritment of cold frame attachments for raised beds! We offer cold frame attachments that are measured to fit perfectly on top of our raised garden beds. If you already own one of our raised beds, you can easily extend the growing season by adding a matching cold frame attachment.
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    Our expert service

    Our team of garden experts are happy to be contacted. You can pose them any questions you might have about the relative advantages of aluminium cold frames over wooden ones. Or simply ask about differences in the costs and benefits of coldframes in relation to greenhouses. You can contact us either by phone or email.

    Frequently asked questions about cold frames

    Expert advice

    Mon. - Fri. 8am - 5pm
    01473 951 332
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