How to Build a Greenhouse from a Kit
A greenhouse is a wonderful addition to any garden. To save money, consider assembling your own from a kit.
Select a location for the hoop house on well-draining, slightly sloping soil and near a water source. The hoop house can be seasonally placed over a raised garden bed to protect tender plants from frost and cold temperatures. If existing plants are too tall for the desired height of the hoop structure, cut the plants back to fit, transplant them to another garden bed or adjust the height or length of the hoop house accordingly. Avoid sites prone to flooding or strong winds and are shaded from nearby trees or structures.
The length and quantity of the 1/2" PVC pipes depend on the width and length of the bed of the hoop house. To determine the length of the pipes, double the width of the bed. For example, a hoop house placed over a 3' bed will need PVC pipes 6' long. To determine the number of PVC pipes, consider that for about every 3' to 4' of house length, a structural support for the plastic roof is needed. For example, a hoop house 12' long will need at least four PVC pipes, one pipe for each end and two pipes for the middle supports.
At one end of the garden bed, push both ends of a PVC pipe into the soil across the desired bed width so that the pipe forms an arc and is firmly set in place, about 1' deep. At the other end of the bed, repeat the same step. Depending on how long the hoop house is, insert the appropriate number of pipes to form the interior supports for the structure.
Place the perforated plastic row cover tightly over the PVC hoops. To hold the cover in place, snap it on with plastic pipe clips that fit snugly over the 1/2" PVC pipes. If the plastic covering is too loose, it may whip in the wind and tear or come loose more easily.
Prior to closing up the hoop house, give plants a thorough watering. At each end of the hoop house, fold the ends of the plastic row cover so that they close like an envelope. Weigh the ends down with a heavy object, such as a brick, sandbag or rock.
If the hoop house isn't tall enough for a person to comfortably move around inside and effectively water the plants, insert drip irrigation hoses across the length of the garden bed. Hook up the ends of the hoses to a water source and water plants as necessary.
During the day, the temperature inside the hoop house builds, and it may be necessary to open the ends of the hoop house for ventilation. Otherwise the plants inside will bake if the heat builds up too much and can't escape. Monitor temperatures inside the house with a maximum-minimum thermometer.