Protect your plants from frost with a simple cold frame that sits right on top of your existing 4′ x 4′ raised bed. The lid is held open with screen door closers, and the entire frame can be moved easily when the weather warms up. Cut the lumber yourself, or have the boards pre-cut at your local home improvement store. Note that you’ll want to measure the height of your raised bed and adjust the cold frame leg measurements as needed. If the bed is taller than 9¼ inches, add the difference to the length of the legs; if it’s shorter, subtract the difference. Scroll down for instructions, or download our printable PDF guide to building your own Raised Bed Cold Frame.

Estimated Time: 2.5 hours (less if you have wood pre-cut)

Difficulty: Easy

raised bed cold frame: open
Woman opening a cold frame that sits on a raised bed.
raised bed cold frame: top open for watering
DIY cold frame stays open using screen door closers, making it easy to water the plants inside.

List of Materials:

  • 6 – 1 x 2 x 8-foot boards
  • 3 – 1 x 4 x 8-foot boards
  • 2 – 2 x 8 x 8-foot boards
  • 4 – .08 x 2 x 4-foot acrylic sheets
  • 2 – 15¾-inch heavy-duty adjustable hold-open pneumatic screen door closers
  • 1 – screen door pull
  • 4 – packages 2 x ½-inch mending braces
  • 2 – packages 1-inch corner braces
  • 3 – 2½ -inch narrow utility hinges
  • ¾-inch washer-head lath screws
  • 1¼-inch deck screws
  • 2-inch deck screws
  • 3-inch deck screws

List of Tools:

  • miter saw or circular saw*
  • drill/driver with #10 countersink bit
  • jigsaw with fine-tooth blade, heavy-duty utility knife, or plastic cutter (for cutting acrylic)
  • clamps
  • square
  • measuring tape

or can have lumber pre-cut at home improvement store per dimensions in Parts List

Parts List

 

PartQuantitySize
Inside End Stretcher23/4 x 1 1/2 x 7 5/8
Outside End Stretcher23/4 x 1 1/2 x 10 5/8
Top End Rails23/4 x 1 1/2 x 49 1/4
Bottom End Rails23/4 x 1 1/2 x 48 1/4
Short End Stiles23/4 x 1 1/2 x 3 1/2
Long End Stiles23/4 x 1 1/2 x 11 3/4
Front Legs21 1/2 x 1 1/2 x 15 7/16
Back Legs21 1/2 x 1 1/2 x 23 5/8
Front Rails23/4 x 1 1/2 x 51 1/2
Front Stiles23/4 x 3 1/2 x 3 5/16
Rear Rails23/4 x 1 1/2 x 51 1/2
Rear Stiles23/4 x 3 1/2 x 11 3/4
Rear Stretcher13/4 x 1 1/2 x 11 3/4
Rear Legs21 1/2 x 1 1/2 x 23 7/8
Hinge Board13/4 x 1 1/2 x 54 3/4
Front Panel15 3/4 x 48
Side Panels214 3/4** x 48
Back Panel114 1/2 x 48
Lid Rails23/4 x 3 1/2 x 47 1/2
Lid Stiles23/4 x 3 1/2 x 49
Lid Stretcher113/4 x 3 1/2 x 42
Lid Panels224 x 48
 

**at widest end – refer to cutting diagram for full dimensions

Cutting Diagram: Wood

simple cold frame: wood cutting diagram

Cutting Diagram: Acrylic

simple cold frame: acrylic cutting diagram

Note: Check the acrylic sheet panels periodically for gaps along the edges, as they may form during large swings of warm and cool temperatures. Add additional ¾-inch washer-head lath screws at these points as needed. If cracks form, use clear, small project construction adhesive or clear silicon sealant caulk to repair.

Finished Dimensions of Raised Bed Cold Frame

  • Height: 24 7/8* inches
  • Width: 51 inches
  • Depth: 49 1/2 inches
    *at highest point

 

Design by Chris Hill.