If you love gardening year round, then a greenhouse would make a very fine addition to your landscape plan. Here is how to design a simple PVC hoop greenhouse.
1/2 inch PVC tubing, about 60 feet, for ridge line
Two 1/2 inch diameter T connectors
Eighteen 1/2 inch diameter cross connectors
Rubber mallet
(Make sure smaller tubing fits inside larger tubing before you buy it).
Clear or blue plastic ground sheet, with grommets, 60 feet by 20 feet
300 feet of thin clothesline
Drill and small bit
Four 16 foot long 2 by 4's
Step1
Cut one inch PVC tubing into 20 foot lengths. Cut 3/4 inch tubing in eight inch lengths. Cut 1/2 inch tubing in 3 foot lengths.
Step2
Lay out your garden area so that its length is in line with the path of the sun. You may wish to level the ground by digging the area up and adding sand, gravel or other material. Place a spirit level on a long 2 by 4 and lay it across your area. Add or remove material until the area is level in all directions.
Step3
Beginning at one corner of the cleared space, use a rubber mallet to drive the 3/4 inch diameter stakes into the ground every three feet along the two long sides of your garden space. Keep the stakes as upright as possible.
Step4
Take your first length of 1 inch diameter PVC and insert the end of the first stake into one end of the pipe. Insert pipe through a T-connector, with the T pointing toward the center of the garden area. Arch the pipe and insert the end of the opposite stake. Repeat for the far end of the garden, with the T-connector pointing toward the center of the garden from that end.
Step5
The remaining arches will use cross connectors. Insert one stake into one end of your tube, then insert tube through cross connector. Insert opposite stake into other end of tube arch.
Step6
Insert half inch tube lengths into the cross connectors between the "ribs" or arches. Use instant adhesive if the structure will be permanent, otherwise, connect without adhesive for easy disassembly and reassembly. Cover structure with plastic sheeting. If desired, especially in windy areas, either secure sheeting with clothesline wound around arches and through the grommets in your plastic sheeting, or use PVC clips. Make clips by slitting PVC pipe lengthwise and cutting it into four or six inch lengths. Open your greenhouse at either end if it gets too hot inside. You may choose to buy a small heater to use in winter. Follow all safety precautions given by the manufacturer of your heater.
Step7
Use lengths of two by four laid along the sides of your greenhouse to help anchor the sheeting in case of high winds. Fix any tears in the sheeting with duct tape as needed. Do not stretch sheeting overly tight, as it will be more likely to tear.
Tips & Warnings
Follow all manufacturer's safety warnings if you choose to use a heater in winter.
Do not stretch sheeting too tight or it will tear.
Novice 
