FACILITIES FOR SECONDARY SCHOOLS
By Ron Biondo,
Teachers, administrators and school board
members have many decisions to make when considering the addition of a
greenhouse to their facilities. This document has been prepared to help
the decision makers make informed decisions.
The first thing to address is whether a greenhouse
is justified? Across the nation there is an increasing need to prepare
students for the many careers related to the horticulture and the plant
sciences fields. Horticulture science is considered one of the fastest
growing segments of the agriculture industry, while plant biotechnology
and genetic engineering are also booming. Students that gain experiences
through greenhouse activities have a distinct advantage over those who
do not when it comes to preparation for career in those fields.
It is important that people whose business
is greenhouse construction are involved in new greenhouse construction
projects. Those people have an understanding of the unique requirements
involved in growing plants under glass. If the school district is building
a new building or an addition that includes a greenhouse, prepare a separate
contract with a greenhouse builder to design and build the greenhouse.
Although this requires more effort, it will ensure the construction of
a functional greenhouse structure.
The following addresses specifications to
consider when planning a greenhouse.
The size of the structure obviously is dependent
on the anticipated use and the number of students involved in instruction.
A minimum of 60 square feet of greenhouse area per student, with
30 square feet bench area per student should be provided (i.e. minimums
for class of 25: 1,500 sq. ft. greenhouse space and 750 sq. ft. bench
A headhouse in which supplies can be stored
and plants potted should be attached to the greenhouse growing space.
A minimum of 600 square feet should be available for this purpose.
Typically, a headhouse will have a partition between it and the greenhouse
The location of the greenhouse facility is
very important. Ideally, it should have an east-west orientation on the
south side of the school. This orientation allows the greatest light transmission
for plant growth.
It should also be accessible through a door
connecting it with the agriscience/horticulture classroom. Plants need
frequent care and should be checked for water and temperature needs a
minimum of 2-3 times a day. Regular visits are made easy when the greenhouse
is attached to the classroom. This is particularly important during inclement
School security lights, parking lot lights,
football field lights, and car lights can disrupt the timing of crops.
Keep this in mind when locating the house. It may be necessary to protect
the greenhouse crops from those sources of light.
Build the best possible
structure that can be afforded because it is seldom that a facility is
upgraded once it is installed.
A. Begin with an aluminum framework or an aluminum and steel combination
framework. Though somewhat costly, they are long lasting and maintenance-free.
Install a greenhouse that is high at the gutters to allow for the installation
of energy curtains.
B. Pour a solid concrete floor with plenty of drains. Concrete may be
expensive, but it is very easy to keep clean of weeds and growing medium.
Concrete floors also permit greater mobility for physically disadvantaged
C. Cover the house with polycarbonate structured sheets treated to resist
ultraviolet wavelengths or tempered glass.
1. Polycarbonate has a number
a. It is much stronger than glass, but lighter in weight.
b. It has good insulation properties.
c. It has excellent light transmission.
d. It is flame retardant.
2. Tempered glass also has
a. It provides
excellent light transmission for plant
b. It is long lasting.
c. Tempered glass is stronger than regular glass.
d. However tempered glass may still break during
it has a high initial cost.
3. Other common glazing materials
are generally less
suitable for school greenhouses:
a. Fiberglass loses light transmission as it wears
out and it
becomes extremely flammable as it ages
fibers become exposed.
b. Polyethylene is the least expensive covering
material, but it tears and must be replaced every
years depending on the thickness of the poly used.
c. Acrylic has good light transmission, but it is brittle.
4. A number of materials
are effectively used for benching.
Extruded metal is commonly
used. It provides good air
circulation and allows water
to drain from pots. Plastic is also
becoming more widely used.
Keep benches narrow enough
for students to reach for
and care for plants. They should
not have to reach more that
30", so limit the width of benches
access from two sides to 5 feet.
5. Leave wider aisles than
would be found in a commercial
greenhouse to accommodate
class size groups and students
with special needs.
Perhaps the most important greenhouse consideration is the ability to
control the temperature at all times (weekends and holidays included).
1. An automatic temperature
control system, preferably
computerized, should be included.
2. Heating of the house should
be done by unit gas heaters.
Never tie the greenhouse heat
to the school boiler room.
3. Cooling is a must, and
the best method of cooling involves
a fan and pad system. A greenhouse
can get much too hot for
plants, even in April, May,
June, September and October when
school is in session.
4. Ventilation alone can cool
a house during many times of
the year. Ventilation can
be accomplished with vents and an
5. Consider installing energy
curtains that reduce heat loss
at night during cold periods
and keep plants cooler in the day
during warm periods. Modern
commercial greenhouses use
energy curtains extensively.
6. It is often useful to divide
the greenhouse with a wall and
to separate environmental
controls so that one room can be
kept at less than 60 degrees
at night and the other above 60
degrees at night. This allows
the students to work with plants
requiring different conditions.
The headhouse should have:
1. 16-20 feet of potting
2. An outside entry large
enough for supplies and
wheelbarrows. (An overhead
door should be considered if
there is a need for vehicle
3. Storage space for growing
media and pots.
4. Separate temperature control
from the greenhouse.
5. A custodial sink.
* Translucent polycarbonate sheets make a good glazing material for the
1. The greenhouse and headhouse
should have waterproof
electrical outlets for
pumps, lights, timers and other items
that may be used with laboratory
exercises. Also, enough
water faucets should be installed
so hoses can easily reach
all benches and so 50' hose
fulfill the need.
2. It is also recommended
that a large capacity water heater
be installed to reduce the
shock to plants created by cold
water. Research has shown
that use of cold water significantly
slows growth and development.
3. Associated with the water
system, it is recommended to
install a fertilizer injector
system with the greenhouse
plumbing. Controls should
be installed with the injector system
that allows it to be switched
on or off.
With a greenhouse and the growing of plants comes the need to use pesticides
and growth regulators. An appropriate, locked storage cabinet, vented
to the outside should be installed in the headhouse to store chemicals.
If security is a concern, consider a cyclone fence encompassing the greenhouse
to keep vandals away. Security lighting may also be beneficial as long
as the light itself doesn’t shine on the greenhouse causing photoperiodic
problems with the greenhouse crops. Fixtures with a shield should be selected
and installed in a manner that will direct all light away from the greenhouse.
LISTING OF GREENHOUSE
BUILDERS AND DESIGNERS
Completed in Illinois
Mr. Carl J. Duewer
All American Associates
P.O. Box 72Mason City, IL 62664
(217) 482-3500 or (800) 482-3566
(Materials, Installation, Consultants)
Barry High School, Bureau Valley High
School, Bushnell-Prairie City High School, Casey-Westfield High
School, DuQuoin School District, Griggsville High School, Mascoutah
CUSD #19, Monticello High School, Northwestern High School, Olympia
High School, Paxton-Buckley-Loda High School, Rockridge High School,
Redbud High School, Rushville High School, Shiloh Community Schools,
Southeastern High School, Waterloo High School, Wayne City CUSD
#100, Woodland High School
Mr. Pete Hummert, Greenhouse Engineer
4500 Earth City Expressway
Earth City, MO 63045
Office (314) 506-4500 x 145
Fax (314) 506-4547
High School, Wesclin High School, Athens High School, Highland High
School, Eldorado High School, Beardstown High School, West Richland
High School, Carmi-White Community Unit, Westmer High School, Valmeyer
| Mr. Greg Schlechty Midwest
Ludy Greenhouse Mfg. Corp.
Office (219) 490-4005
Fax (219) 490-5044
| Oswego High
School, Hononegah High School
| Mr. John McPhillips
Rough Brothers, Inc.
5513 Vine Street
P.O. Box 16010
Office (800) 543-7351
Fax (513) 242-0816
High School, Glenbrook South High School, Lockport High School, Naperville
North High School, Waubonsie Valley High School
Stuppy Greenhouse Manufacturing, Inc.
P.O. Box 12456
North Kansas City, MO 64116
| Mr. Peter
United Greenhouse Systems
123 W. Hillside Ave.
Barrington, IL 60010Office
(847) 842-1624 Fax (847) 842-1692
| Rochelle High
School, Hiawatha High School
| Mr. Richard
Van Wingerden Greenhouse Company
4078 Haywood Rd.Horse Shoe, NC 28742
Office (828) 891-7389
Fax (828) 891-5882
| None in Illinois
Has developed a package for High Schools.
| Mr. Arie Boot
P.O. Box 529
Thornburg, VA 22565
Office (540) 582-3159
Fax (540) 582-6103
| None in Illinois
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