How to Build a Mini Indoor Greenhouse

If you are thinking of starting seeds in the house for planting outside, or even if you want to try growing your vegetables on a sunny windowsill, a mini greenhouse will speed germination and promote rapid growth. You can buy a mini greenhouse at your local hardware or garden-supply store, but making your own is a simple project that starts with a new or used window box, long planter or even a plastic storage box.

Things You'll Need

• Window boxes, planters or plastic containers
• 2 to 3 coat hangers
• Wire cutters
• All-purpose potting soil
• Perlite
• Seeds
• Clear plastic sheeting
• Tape or staple gun

Instructions

1. Select a window box, long planter or plastic storage box that will fit on your windowsill. Fill the container with equal parts of all-purpose potting soil and perlite. Mix the materials well and water to thoroughly moisten the soil.

2. Cut the hook off the coat hangers with wire cutters. Straighten the wire and bend it into a "U" shape.

3. Place the wire at one end of the planting container so the ends rest inside the box and the wire creates an arch. Bend the wire so its ends fit snugly against the inside of the container. Place another wire arch at the opposite end of the planter. Add an arch in the center is your planter is more than 1 1/2 feet long.

4. Plant your seeds in the soil, following the depth and spacing specified on the seed packet.

5. Cut a piece of plastic sheeting long enough to cover the length of the planter and wide enough to cover the arch plus 4 inches. Tuck the long end of the plastic into the planter and secure it with tape or staples from your staple gun.

6. Pull the plastic over the arch and tuck it into the container. Leave this end free so that you can open and close the greenhouse to adjust the humidity level and temperature.

7. Cover the open ends with clear plastic sheeting. Tape the plastic to the wire arch to complete the greenhouse.

Tips & Warnings

• Place the greenhouse on a sunny windowsill.

• Although you can recycle any plastic you have, plastic designed for weatherizing windows works best.

• Avoid placing a mini greenhouse in direct afternoon sun from western or southern windows. Monitor your greenhouse closely to prevent overheating in the afternoon sun.