If you are looking for ways to extend the garden season, this raised bed greenhouse may be your solution. I found this project on Apartment Therapy. You can find several plans for this online, but I especially like the addition of wire mesh to give this one stability. With the mesh, the greenhouse is less likely to suffer damage from winds or heavy rains.
The ribs are made from 1/2-inch PVC pipe (you can get them for under $1.50 each). If you already have raised beds, this project is inexpensive and easy-to-make. All you need is odds and ends of wood for braces, the PVC pipe and some pipe clamps. You will also need two hinges and some chain to allow you to open and close the greenhouse.
I'm thinking about borrowing this design and covering mine with floating row cover so I can grow cabbage, broccoli and cauliflower without worries about cabbage worms. Row cover would also protect plants from late spring and early fall frosts.
Until Next Time . . . HAPPY GARDENING!