As the gardening season comes to an end, it can be challenging to know what to do with all that extra time. However, with the addition of a cold frame, you can extend your gardening season well into the colder months. This simple structure can protect your plants from harsh weather conditions and give you the opportunity to grow fresh produce throughout the year. In this post, we will discuss cold frame design DIY and provide instructions on building a cold frame from various materials.
What is a Cold Frame
What is a cold frame? A cold frame is a simple structure that can help extend the growing season by providing protection and warmth to your plants. It looks like a small box with a sloping roof, typically made of wood or metal framing and topped with a transparent material such as aglass or clear plastic. The purpose of a cold frame is to trap heat and create a microclimate to help your plants thrive in cooler months. By creating this warmer environment, your plants can continue to grow and even produce fresh produce for an extended period.
How to Make a Cold Frame Lid
When it comes to the lid of your cold frame, the choice of material is crucial. It should allow sunlight in while providing insulation for cooler temperatures. One popular choice is a pane of glass, which offers excellent light transmittance and heat retention. Alternatively, you could use a clear plastic cover, which is lighter and less prone to breakage. Polycarbonate panels are another good option due to their durability, insulation capabilities, and light transmittance. Whatever material you choose, ensure it is sufficiently sturdy and transparent to enable your plants to continue photosynthesis, even as the outside temperatures drop.
When my Dad built his multiple cold frames from both concrete block and wood he had a lot of Visqueen plastic wrap. So he just built a wooden frame the size of his cold frame from 2×2’s, using cross bracing as needed with 2×2’s and we stapled the Visqueen to this frame, then put hinges on creating an easy lightweight lid! Also if it ever got windy he put hood and eye latch to hold it down as needed.
How to Build a Wooden Cold Frame
How to build a cold frame? Building a cold frame is a relatively simple process and can be done using different materials, depending on your budget and skill level. For example, a low-cost option is to use an old window and hinges to create a lid. Here are the standard steps for building a basic wooden cold frame:
- Choose the location: Pick a spot that receives at least six hours of sunlight daily and is sheltered from strong winds.
- Choose the dimensions: Depending on how much space you have, determine the size of the cold frame and how high you want it.
- Create the frame: Cut four pieces of wood to your desired dimensions to create the frame’s sides. Then, assemble the four pieces to form a rectangular box.
- Add the lid: Cut a piece of wood to form the roof and attach it to the top of the frame using hinges. Ensure the lid can open and close easily.
- Add transparent elements: Cut a transparent material such as glass or clear plastic, to fit the frame’s dimensions. Attach it to the frame using nails or screws.
How to Build a Concrete Block Cold Frame
Building a cold frame out of concrete blocks is another practical and sturdy option. This type of cold frame is durable, resistant to harsh weather, and provides a great thermal mass, which means it can store and release heat over time. Here’s your step-by-step guide:
- Choose the location: As with the wooden frame, select a location that gets at least six hours of daily sunlight and is sheltered from strong winds.
- Lay out your blocks: Determine the dimensions and lay out your concrete blocks accordingly. A simple layout would involve creating a rectangular shape using the blocks.
- Stack the blocks: Stack more blocks on top to achieve the desired height, making sure they are stable and secure. You might want to use a bonding adhesive to keep the blocks together.
- Add the lid: Just like with a wooden frame, you need a lid for your cold frame. You can use an old window or a framed piece of clear plastic or glass. Attach this to one edge using hinges, so it can be opened and closed.
- Seal gaps: If there are any gaps between the blocks, seal them with a concrete patching compound to ensure heat stays in and pests stay out.
Remember, the concrete’s thermal mass will help to accumulate heat during the day and release it slowly during the night, aiding your plants’ growth despite the cold weather.
How to Build a PVC Cold Frame
For those looking for an affordable and easy-to-assemble option, a cold frame made from PVC pipe can be an excellent choice. Lightweight and highly adaptable, PVC pipe provides a robust framework that can be easily covered with clear plastic or a protective cloth. Here’s a simple guide on how to build a PVC pipe cold frame:
- Choose the location: As always, select a spot that gets ample sunlight and is shielded from harsh winds.
- Plan the dimensions: Based on your available space, decide on the dimensions of your cold frame. A typical size might be 3 feet wide by 6 feet long and about 1.5 feet high.
- Build the base: Use four pieces of PVC pipe and four 3-way connectors to construct a rectangular base. Make sure all the pipe sections fit snugly into the connectors.
- Create the arches: Cut two longer pieces of PVC pipe to form the arches for the roof. Attach each end of these pieces to the base’s connectors to create a half-cylinder shape.
- Attach the cover: Cut a piece of clear plastic or gardening cloth to match your frame’s dimensions plus extra on each side for securing. Drape it over the structure making sure it’s taut, then secure it to the base using zip ties or clips. Make sure to leave one end easy to open for ventilation and access to your plants.
- Add reinforcements: For added stability, you can drive rebar stakes into the ground and slip the ends of your PVC pipes over them.
Remember, PVC pipe cold frames are not as sturdy or insulated as wooden or concrete block ones. However, their light weight makes them easy to move and adjust according to your gardening needs. It’s a practical and economical way to extend your growing season.
How to Make a Cold Frame from Old Windows
Utilizing old windows for constructing a cold frame is an ingenious way of recycling and creating a functional, beautiful, and cost-effective solution for extending your growing season. Here’s how to go about it:
- Select your windows: Choose old windows that are still in good condition – ensuring they are free from cracks or major defects. The size of the windows will determine the dimensions of your cold frame.
- Construct the base: Similar to the wooden frame, you will need four pieces of lumber cut according to the dimensions of your chosen windows. Assemble these pieces to form a rectangular base.
- Build the sides: Use additional lumber to create sides that slope downwards from the back to the front. This sloping design will maximize sunlight capture.
- Attach the windows: Place your windows on top of the frame, ensuring they cover the structure completely. Attach the windows to the frame using sturdy hinges.
- Seal the frame: Check for any gaps or openings in the frame that may let cold air enter. Fill these gaps with a weatherproof sealant to ensure good insulation.
- Optional – Add a prop: If you want to be able to prop your window open for ventilation, you can add a simple wooden stick or an adjustable stay.
Remember, using old windows not only makes this a cost-effective solution, but can also give your cold frame a rustic, charming aesthetic. Moreover, while this type of cold frame is not as portable as a PVC one, it can offer better insulation and durability.
How to Build a Cold Frame from Pallets
A cold frame made from pallets can be a wonderful eco-friendly option that allows you to recycle old pallets while creating a functional and rustic cold frame. Pallets are generally sturdy and, when properly treated, can withstand weather conditions. Here’s your step-by-step guide:
- Select your pallets: Choose pallets that are still in good condition – free from rot and major defects. The size of your pallets will determine the dimensions of your cold frame.
- Disassemble the pallets: Use a saw or a pry bar to carefully disassemble the pallets into individual boards. Remember to remove any nails or screws.
- Build the base and sides: Using the reclaimed pallet boards, construct a rectangular base and four sides. The backside should be taller than the front to allow sunlight to reach all areas inside the cold frame.
- Add the lid: You can either build a lid from additional pallet boards or use an old window if one fits. Make sure it’s attached with hinges for easy opening and closing.
- Seal the frame: Check for any gaps or openings in the frame that may allow cold air to enter. Fill these with a weatherproof sealant to ensure good insulation.
- Optional – Add a prop: To aid in ventilation, you might want to add a prop, such as a wooden stick or an adjustable stay, to keep the lid open when needed.
Remember, building a cold frame from pallets is not just an affordable option, but it also allows you to recycle and reuse, contributing to a more sustainable environment. However, ensure the pallets are safe and haven’t been treated with harmful chemicals, as these could affect your plants.
Happy Gardening!
By building a cold frame, you can extend your gardening season and continue to enjoy fresh produce well into the fall and winter months. It is a simple and affordable way to protect your plants from harsh weather conditions and create a microclimate to keep them growing. Whether you construct it using wood, PVC pipes, or cinder blocks, a cold frame is an excellent investment for home gardeners. So why not try building one this season and see the benefits for yourself?
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