Selecting A Site For Your Growing Dome Greenhouse

You may want to check to see if there are any restrictions on greenhouses in your area - for example, local subdivision, county or city Planning and Zoning Departments may be consulted on this matter. Also, neighbors may be informed and, hopefully, will support your efforts and even benefit from your excess produce.

Often the dome can be classified as a temporary structure or agricultural, as it bolts together and unbolts if you choose. The smaller domes do not need a concrete foundation. The larger domes (33', 42', & 51') can either have a full concrete foundation or sit on concrete piers. Here are some factors to consider when choosing your site for the dome:

Solar horizon: Preferably unrestricted to the south, east and west - in that order of preference. You can approach a solar architect in your area if you have questions or need advice. A solar pathfinder is a useful tool to borrow. If you have a lot of sun in the summer this may cause overheating problems. Deciduous trees may be helpful as they lose their leaves allowing solar gain in the winter while still providing shade in the summer. If you have to choose between morning sun or afternoon sun, the plants prefer the morning sun to get them off to an early start. The dome site needs to have a minimum of 4 to 5 hours of clear sun for the dome to perform effectively. If it has less than this, the dome will still perform but you need perhaps to add auxiliary heat in the winter months. You can consult a solar architect.

Proximity to dwelling: If the dome is fairly close to the house it's easier to pop in and pick fresh greens or a few herbs for your salad or stir-fry. Also, it's easier to shovel a path through the snow and to supply power and water to a dome close to the house.

Shelter: Choosing a location sheltered from the wind is useful in order to reduce heat loss in the winter, and also reduce stress on the vents during high winds.

Soil: It is preferable to start with a level site. Otherwise, use a slope to the south. The site needs to be leveled, and usually owners choose to excavate the high side in combination with building up the low side often using a retaining wall made of landscape timbers or rocks.

If your soil is poor and rocky you may choose to excavate down a foot or two, remove the poor soil and bring in good topsoil, or build up on top of the existing soil. It is strongly advised to remove all perennial weed at this juncture, as removing them later is a proverbial pain. Many dome owners have regretted omitting this step (including myself). Also remove creeping weeds with underground rhizomes to a distance of a couple of feet away from the dome, as they can creep under the wall and right through the insulation! If you have gophers or burrowing animals, you may want to cover the floor of the dome with hardware cloth (galvanized metal screen approx. 1/4" mesh.)

Services: You can install electricity and water supply, although these are not necessary for the dome to function and can be added later if you choose. Some owners use polyethylene water pipe, which can freeze and thaw without rupturing. During the winter, plants in the dome can also be watered directly from the water tank, as water demands are usually low and the tank can be topped off once a month or so. In the summer the dome can be hand-watered, using a hose, or a sprinkler system. Electricity is helpful for an auxiliary heat supply for those sub-zero winter nights! Propane heat can also be used for standby heat at those times and is preferred by most Dome Owners. Your plants will enjoy the extra CO2 produced as well as the heat. The 26-ft dome has a solar powered cooling fan as part of the standard kit. The larger domes (33', 42', & 51') have 110v powered cooling fans as standard, but they can be upgraded to solar powered cooling fans for additional cost. More fans can be provided for hotter climates. Growing Spaces can give you personal advice on your particular location and we are more than happy to consult with you on any aspect of installing or maintaining your Growing DomeTM.