Building an outdoor plant box with a built-in cold frame is a fantastic way to extend your growing season and protect delicate plants from frost. Here’s a step-by-step guide to help you create this versatile gardening structure.

Materials Needed:

- Untreated cedar or redwood lumber (resistant to rot)

- Screws or nails

- Hinges and a latch

- Clear polycarbonate panels or old windows for the cold frame lid

- Drill and saw

- Measuring tape and level

Step 1: Design Your Plant Box

Decide on the size of your plant box. A common dimension is 4x4 feet, but adjust based on your space. Cut the lumber to form the sides, ensuring the back is slightly taller than the front for proper drainage.

Step 2: Assemble the Frame

Construct the rectangular frame by screwing the boards together at the corners. Reinforce the structure with corner braces if needed.

Step 3: Add the Cold Frame Lid

Attach hinges to the back of the box and secure the polycarbonate panel or old window to create a sloped lid. This allows sunlight in while protecting plants from cold.

Step 4: Install the Latch

Add a latch to the front to keep the lid secure during windy weather.

Step 5: Fill and Plant

Fill the box with quality soil and compost. Plant cold-hardy vegetables or herbs, and use the cold frame to shield them from early frosts.

With this DIY project, you’ll enjoy fresh produce even in cooler months!