Build a Cold Frame Greenhouse: 3 Practical Examples

Discover 3 practical examples of how to build a cold frame greenhouse for sustainable gardening.
By Taylor

Introduction

A cold frame greenhouse is a simple yet effective way to extend your growing season, allowing you to start plants earlier in spring and protect them from frost in fall. These structures trap heat from the sun, creating a warm environment for your plants. Building a cold frame can be done with minimal materials and effort, making it a perfect DIY project for gardeners of all skill levels. Here are three diverse, practical examples of how to build a cold frame greenhouse.

Example 1: Wooden Cold Frame

Building a wooden cold frame is a classic approach that provides good insulation and aesthetics. This design uses recycled wooden pallets, making it an eco-friendly option.

Start by obtaining two wooden pallets. Position one pallet flat on the ground as the base. Then, take the second pallet, cut it in half, and use these pieces to create the sides of the frame, securing them to the base with screws. For the back wall, use another piece of wood cut to your desired height, ensuring it’s taller than the front to allow for better sunlight capture. Finally, add a clear plastic or glass window (you can use an old window if available) on top, which can be propped open with hinges for ventilation. This cold frame will effectively warm up your seedlings and protect them from harsh weather.

Notes:

  • Ensure the glass or plastic cover is secured to prevent it from blowing away.
  • You can paint the wooden frame with non-toxic paint for added durability and visual appeal.

Example 2: Straw Bale Cold Frame

If you’re looking for a unique and sustainable option, a straw bale cold frame is an excellent choice. This design not only provides insulation but also utilizes biodegradable materials.

To start, arrange four straw bales into a rectangular shape on a level surface, leaving an opening for access. The bales will form the walls of the cold frame. Next, place a clear plastic sheet or old window frames on top of the bales to create a roof. To secure the roof, you can use bricks or stones to weigh it down at the corners. This structure will maintain warmth due to the straw’s insulating properties and is perfect for growing seedlings or hardening off plants before transferring them to the garden.

Notes:

  • Straw bales can be composted after using, making this an entirely sustainable project.
  • You can adjust the height of the cold frame by stacking more bales if needed.

Example 3: PVC Pipe Cold Frame

For a more modern and lightweight approach, a PVC pipe cold frame is easy to assemble and disassemble, making it great for those who may want to relocate it seasonally.

Begin by cutting four pieces of PVC pipe to your desired height for the frame. Using these pipes, create a rectangular shape for the base by connecting them with elbow joints. Next, cut additional pipes to create vertical supports at each corner. Use T-joints to connect the vertical pipes to the base. For the top, cut a larger piece of clear plastic sheeting that will cover the frame. You can either secure the plastic with clamps or create a hinged roof by attaching it with hinges on one side. This design is lightweight and can be moved easily while still providing adequate protection for your plants.

Notes:

  • Ensure to choose UV-resistant plastic to prolong the life of your cold frame.
  • You can add wheels to the base for even easier mobility.

By exploring these examples of how to build a cold frame greenhouse, you can take a step towards more sustainable gardening while enjoying the beauty and benefits of growing your own plants year-round!