Easy Greenhouse (Cold Box)

Introduction: Easy Greenhouse (Cold Box)

A cold box is used to start seeds and to help force seeds to germinate before they are in season.

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Step 1: Step One: Materials List

You start with 5-3/4"x10' Schedule 40 PVC pipe, 8-3/4" elbows with a 1/2" to 3/4" screw in slot, 8-1/2" to 3/4" connections, 1- roll of 3.5mil clear plastic sheeting and 1 roll of duct tape.

Step 2: Step Two: Materials Close-up

Elbow connections and screw in connections

Step 3: Step Three: Materials Close-up

Plastic Sheeting and Duct Tape

Step 4: Step Four: Needed Tools

All you need for tools is a hack saw, measuring tape, Sharpie and a razor knife.

Step 5: Step Five: Cutting and Assembly

So you cut your PVC pipe into 5' sections. The take 2-5' sections and and cut them into 4-2.5' sections. Then you take the corner connections and put them together.

Step 6: Step Six: Assembly of Top and Bottom Sections

Before you know it you have two boxes. Or your top and bottom pieces.

Step 7: Step Seven: Adding the Corner Connections

Then you screw the 1/2" to 3/4" connections in to their corner locations.

Step 8: Step Eight: Adding the Uprights

Then with the remaining 5' sections you place them into the corner pieces on both the top and bottom sections. Essentially, you are build a big cube.

Step 9: Step Nine: Adding Plastic Sheeting and Shelves

Wrap it in the plastic sheeting and tape you edges with duct tape. I had an extra piece of pipe and end caps that I filled with sand to hold the front flap down. And for shelves I used some metal shelves I had left from a previous indoor project. Clamps will hold the flap in place and keep the wind out.

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    2 Discussions


    Hi there... Love your design!!! How did you find the PVC being able to bear the weight of plants and soil? Did you have any issues with buckling or bowing? I'd really like to know as I am considering this for my yard... How did you end up attaching the shelves to the frame as well? Did they add sturdiness to it...? Finally were you able to dissassemble this when the season was over? Thanks very much....


    10 years ago on Introduction

    So just to update everyone that sees this and wonders if it works. I planted a total of 72 tomato plants, 25 Pepper plants and various flowers for this spring planting season. I lost only 10 tomato plants, no pepper plants and only a few flower plants. This greenhouse worked great. I am very happy with the design.