I start my seedlings inside and as they start growing I find that they need to be "hardened" to the outdoors. Without hardening, the wind will blow small plants often times breaking and killing them. Also smaller plants need the daylight sun to grow stronger, something they don't get indoors. I used to have a green house, but I found often on a sunny day the plants would die from overheat it I wasn't there to tend to them.. I have made this same concept with discarded windows and it worked well. However at planting time until the next spring, I would have to disassemble and store it for the next season. The beauty of this is at end of season, you just toss into recycling, no storage needed.

Step 1: Things You Need to Start

1. Strong cardboard box ( mine was 21x16x15)

2. Double stick tape

3. Boxing tape

4. Ruler

5. Box cutter

6. Plastic food wrap

Step 2: Open Up Your Box

Cut off the top flaps

Step 3: Measure Out Windows

Put a 2 inch border around front and two sides, nothing is needed on the back side

Step 4: Cut Out Windows

You will actually have an easier time cutting out the windows if you leave the bottom flaps open as the box will lay flat for the cutting

Step 5: Put Double-stick Tape On

Outline your windows with the double stick

Step 6: 2 Strips of Doublestick Tape

Across the backside of box to help hold the plastic wrap. Then tape up bottom box flaps to put the box back together and remove the out layer of the doublestick tape.

Step 7: Wrap It Up

It works better with some help here. Start in the lower back and have a friend hold the box as you wrap it up in the plastic wrap. Upon finishing the plastic wrap, I also ran boxing tape from inner top side of box to the bottom of the box. 3 strips of tape in the back and one each across center of each side window and two across front window to help hold plastic wrap in place.

Step 8: Ready for the Outdoors.

I put a couple discarded pavers (bricks) in the bottom for wind ballast and put my young plants in. The plants get the sun they need, moderate wind will not tear them apart, and they will not overheat. At end of day, the plants go back into the garage along with the box. I can leave for work and not worry about them during the day. What about rain you say? I find rain will also damage seedlings as well as the box. I don't use it on rainy days.