Building a Cold Frame from Salvaged Materials

A cold frame is a simple yet valuable tool for extending the gardening season, allowing you to start seeds earlier in the spring, protect tender seedlings from frost, and prolong the harvest of cool-season crops in the fall. While you can purchase ready-made cold frames, building your own from salvaged materials offers a cost-effective and environmentally friendly approach. This guide will walk you through the steps of constructing a durable and functional cold frame using readily available recycled resources.

Gathering Your Materials

The beauty of a salvaged cold frame lies in its resourcefulness. With a little creativity and ingenuity, you can transform discarded materials into a valuable gardening asset. Here's a list of potential materials to look for:

The Frame:

• Wooden Pallets: These sturdy platforms offer excellent structural support and are readily available at construction sites or behind businesses. Look for pallets with minimal damage or warping.
• Reclaimed Windows or Doors: Glass panes from old windows or doors provide excellent light transmission. Check local salvage yards or online marketplaces for salvaged windows.
• Old Window Frames: Even if the glass is broken, the frames themselves can be used to create a sturdy structure for the cold frame.
• Scrap Lumber: Use leftover boards from previous projects or purchase salvaged lumber from a lumberyard.
• Metal Piping: Consider using metal piping or conduit to create a robust frame if you need something more durable than wood.

The Cover:

• Glass: Old windows, storm windows, or even greenhouse glazing panels can be used to create a transparent cover for your cold frame.
• Clear Acrylic Sheets: These are available at hardware stores and can be cut to size for a durable and weather-resistant cover.
• Polycarbonate Panels: These lightweight and impact-resistant panels are a good option for cold frame covers. They can be purchased from home improvement stores or online.
• Recycled Plastic: Large, clear plastic containers (like those used for food storage) can be repurposed to create a makeshift cover.

Other Materials:

• Screws or Nails: For securing the frame together.
• Weather Stripping: For sealing gaps between the cover and the frame.
• Hinges: If you're using a door-style cover.
• Soil and Compost: For filling the cold frame.
• Landscaping Fabric: Optional for lining the bottom of the frame to prevent weeds.

Designing Your Cold Frame

Before you start building, it's essential to design the size and shape of your cold frame. Consider the following factors:

• Space Availability: Choose a location in your garden that receives ample sunlight and is protected from wind and cold drafts.
• Size Requirements: The size of your cold frame will depend on the number of plants you wish to cultivate. A standard cold frame measures around 4 feet wide by 6 feet long, but you can adjust the dimensions to suit your needs.
• Shape: Most cold frames are rectangular, but you can also create a triangular or curved shape if you desire. The shape will affect the amount of sunlight that reaches the plants.
• Access: Ensure you have easy access to the interior of the cold frame for planting, watering, and harvesting.

Building the Cold Frame

Once you've gathered your materials and designed your cold frame, it's time to start building. Here's a step-by-step guide:

Step 1: Assemble the Frame

• Cut the materials to size: Using a saw, cut the wooden planks, metal piping, or other materials to the desired length to form the frame of your cold frame.
• Create corners: Connect the pieces of the frame at the corners using screws, nails, or brackets. Ensure that the corners are square and stable.
• Attach the base: If you're using a pallet as the base, secure it to the frame using screws or nails. If you're using lumber, build a sturdy rectangular base and attach it to the frame.

Step 2: Install the Cover

• Measure and cut the cover: Measure the opening of the frame and cut the glass, acrylic, or polycarbonate panels to size. Allow for a slight overhang for better water runoff.
• Attach the cover: If you're using glass, you can secure it using glazing strips and screws. Acrylic or polycarbonate panels can be screwed directly into the frame. If you're using a door-style cover, install hinges and a latch.

Step 3: Finishing Touches

• Seal the edges: Apply weather stripping around the edges of the cover to create a tight seal and prevent drafts. This will help to maintain a stable temperature inside the cold frame.
• Add a ventilation system: Install small vents in the top or sides of the cold frame to allow for air circulation and prevent condensation build-up. You can use screens or a simple hinged flap for ventilation.
• Optional: Build a base: If you are not using a pallet for the base, you can build a raised base of bricks or wood to help elevate the cold frame and improve drainage.

Preparing and Using Your Cold Frame

Once your cold frame is built, it's time to prepare it for use. Here's how:

• Choose the right location: Place the cold frame in a sunny location that receives at least six hours of sunlight per day. Ensure that it's protected from wind and cold drafts.
• Fill with soil: Fill the cold frame with a good quality potting mix or garden soil amended with compost. You can also add a layer of landscaping fabric at the bottom to prevent weeds.
• Start seeds or transplant seedlings: You can start seeds directly in the cold frame or transplant seedlings from a seed tray or greenhouse. Space the plants according to their individual needs.
• Water regularly: Cold frames can dry out quickly, so water your plants regularly, especially during hot and dry weather.
• Monitor temperature: Use a thermometer to monitor the temperature inside the cold frame. Adjust the vents to regulate the temperature and ensure optimal conditions for your plants.
• Hardening off: Before transplanting your plants outdoors, gradually acclimate them to the cooler temperatures by removing the cover for short periods each day.

Maintaining Your Cold Frame

To ensure your cold frame continues to provide a nurturing environment for your plants, follow these maintenance tips:

• Clean and disinfect: After each growing season, clean the cold frame thoroughly using a mild soap solution and a disinfectant. This will prevent the spread of diseases and pests.
• Repair any damage: Inspect the frame, cover, and seals regularly and repair any damage promptly. This will help to maintain the integrity of the structure and ensure optimal performance.
• Remove weeds: Regularly remove any weeds that may sprout within the cold frame to prevent competition for nutrients and space.
• Replace the soil: Every few years, replace the soil in the cold frame with fresh potting mix or garden soil. This will help to replenish nutrients and improve drainage.

Building a cold frame from salvaged materials is a rewarding and environmentally friendly project. With a little effort and creativity, you can transform discarded materials into a valuable asset for your garden, allowing you to extend your growing season and enjoy fresh produce for longer. So, take a look around your local salvage yard or online marketplace, and start your cold frame building adventure today!