A dome support is so easy to make. Just bend a 10-foot length of 72-inch PVC pipe from corner to corner of your box, and then another from the opposite corners; then tie or bolt it at the intersection at the top to make a dome that can support any type of cover.
This small greenhouse are 100% recycled, We combined some old building bricks and three roof windows and cleverly assembled them. Then we add a little soil, planted the seeds of our choice and let them grow. In this way, the beautiful greenhouses protect the seedlings from weather and keep them warm until they are planted in a flowerbed or vegetable garden.