Unformatted text preview: able to help to do
the task over short periods of time. Bear in mind, the P94/R96 David S. Ross
Extension agricultural engineer
Department of Agricultural Engineering What should a gardener consider when planning to
build a small hobby greenhouse? What materials should
be used to build it? Does it need heating and cooling?
Where can it be placed on the property? There are
many considerations, and careful planning is important
before a project is started.
Building a home greenhouse does not need to be
expensive or timeconsuming. It can be small and simple, with a minimum investment in materials and
equipment, or it can be a fully equipped, fancy, automated conservatory. The final choice of the type of
greenhouse will depend on the growing space desired,
home architecture, available sites, and costs. The greenhouse must, however, provide the proper environment
for growing plants.
Regardless of the size and type of greenhouse you
choose, consider how much time you have to manage
the system. Do not be too ambitious; some new greenhouse owners find they do not have as much time as
they thought. On the other hand, it is a misconception
that greenhouses require constant attention. The environment can be maintained with minimal upkeep using
automatic controls, which operate the heating, ventilation, watering, humidity, and artificial lighting systems
when no one is home. A hobbyist should invest in
automatic controls and start with easy-to-care-for plants.
Sometimes the hobby grows into a business, so give
some thought to the possibility of expanding your
greenhouse in the future.
Constructing the greenhouse yourself can make the
project more enjoyable and less expensive if you are
handy with tools. Prefabricated greenhouses can be pur- chased, or they can be built of simple frames. However,
only qualified electricians and plumbers should install
the automatic systems. Location
The greenhouse should be located where it gets maximum sunlight. The first choice of location is the south
or southeast side of a building or shade trees. Sunlight
all day is best, but morning sunlight on the east side is
sufficient for plants. An east side location captures the
most November to February sunlight. The next best
sites are southwest and west of major structures, where
plants receive sunlight later in the day. North of major
structures is the least desirable location and is good only
for plants that require little light. Morning sunlight is
most desirable because it allows the plant’s food production process to begin early; thus, growth is maximized.
Deciduous trees, such as maple and oak, can effectively shade the greenhouse from the intense late afternoon summer sun; however, they should not shade the
greenhouse in the morning. Deciduous trees also allow
maximum exposure to the winter sun because they shed
their leaves in the fall. Evergreen trees that have foliage
year round should not be located where they will shade
the greenhouse because they will block the less intense
winter sun. You should aim to maximize winter sun
exposure, particularly if the greenhouse is used all year.
Remember that the sun is lower in the southern sky in
winter causing long shadows to be cast by buildings and
evergreen trees (Figure 1).
Good drainage is another requirement for the site.
When necessary, build the greenhouse above the sur- Issued in furtherance of Cooperative Extension work, acts of May 8 and June 30,1914, in cooperation with the U.S. Department of Agriculture, University of Maryland at College Park,
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