I. Title- GREENHOUSE MANAGEMENT-Basic Greenhouse Structures
Frameworks – Unit 3
II. Situation
Students have worked in greenhouse in Introduction to Horticulture and other classes.
They have little to no experience with technical terms for types of green houses.
III. Materials
 Students need paper and pencil for notes
 PowerPoint (Types of Greenhouses)
 Computer
 Poster Board
 Markers or pencils for drawing
 Plant list or Internet
 Handout for structure type
IV. Vocabulary
 Anchor support post- side posts providing the main structural support for a
greenhouse that are spaced at regular intervals and set in concrete footings
 Cold Frame- an outside propagation structure consisting of a wooden or concrete
block frame with heat supplied by solar radiation through a glass or other
transparent covering
 Even span- A single house that has a roof with an even pitch and even width
 Glass- a type of covering used in greenhouse; comes in several grades; allows
greatest transmission of light
 Gothic arch- basic style of greenhouse with a pointed arch; trusses have been
eliminated
 Hot bed- an outside propagation structure similar to a cold frame except electric or
hot water thermostatically controlled heating is used
 Lean-to- shares a wall with a building and relies on the building structure to
provide some support for the roof.
 Polyethylene- a petroleum-based flexible plastic used for many purposes;
greenhouses can be covered with this
 Purlins- run the length of the structure and are attached to each truss, adding more
structural strength
 Quonset- basic style of greenhouse with curved roof with or without sidewalls
 Ridge and Furrow Greenhouse- a number of greenhouses connected along the
length of the house. Shared walls create larger interior space.
 Rigid structured sheets- a type of covering used in greenhouses commonly made
of polycarbonate and acrylic; it is rigid and resistant to weathering
 Trusses- composed of rafters, chords, and struts that support the roof
 Uneven span- a house with unequal pitches and widths
 Ventilators- moveable units of greenhouse to allow for natural air flow
V. Teaching Objectives
1. List and describe the different types of greenhouses on a quiz with 85 % accuracy.
2. List common framing materials used in greenhouses on a quiz with 90% accuracy.
3. Compare basic types of greenhouse coverings on a quiz with 80% accuracy.
4. Describe the uses of cold frames on a quiz with 80% accuracy.
VI. Teacher Procedures
A. Interest Approach
1. Students get out a piece of paper.
2. Have them draw every type of greenhouse they can think of.
3. Ask what each type is called.
B. Reasons to Learn
1. Why are there different types of greenhouses?
 Different climates
 Different preferences
 Different capacity needs
2. Why do we need to know the different types of greenhouses?
 So we can know what kind we have or maybe need.
3. Why are there different materials used to frame greenhouses?
 Different cost
 Availability
 Appearance preference
 Strength requirements
4. Why are there different materials used to cover greenhouses?
 Cost
 Light requirements
 Durability
5. Why do we need to understand what a cold frame or a hotbed is?
C. Questions to Answers
1. What are some different styles of greenhouses?
 Even span
 Uneven span
 Gothic arch
 Quonset
 Ridge and Furrow
 Lean-to
2. What are some factors to consider when choosing a greenhouse?
 Cost
 Space
 Location
3. What are some factors in choosing the framing material for a greenhouse?
 Strength
 Durability
 Maintenance
 Cost
4. What is glazing?
 Covering on a greenhouse
5. What is a cold frame?
 A small greenhouse used to protect plants or seeds from the environment
6. What is a hotbed?
 A small greenhouse used to protect plants or seed from the environment but uses
outside source for heating.
D. Solution to Problem
GREENHOUSE STYLES
1. Lean-to Greenhouse- shares a wall with a building and relies on the
building structure to provide some support for the roof.

Advantages
 Cheapest
 Easier Instillation
 More Obtainable
 Space

Disadvantage
 Cheapest
 Easier Instillation
 More Obtainable
 Space
2. Even Span Greenhouse- A single house that has a roof with an even pitch
and even width
Advantages
 Common
 Easy to find tables
 Easy to heat and ventilate
 Can add on easily

 Disadvantage
 Expensive
 More space needed
3. Uneven-Span Greenhouse- a house with unequal pitches and widths
 Advantages
 Can be used on uneven ground
 Can be situated to optimize sunlight
 Unique
 Disadvantage
 Expensive
 Difficult to find equipment
 Hard to add on to
4. Gothic Arch- basic style of greenhouse with a pointed arch; trusses have
been eliminated
 Advantages
 Inexpensive
 Is good for shedding snow
 More attractive
 Disadvantages
 Less head room


More difficult to build than Quonset
5. Ridge and Furrow
 Advantages
 Large Capacity
 Lower Energy Cost
 Ability to diversify plants grown

Disadvantages
 Area needed to build
 Cost of building
6. Start Activity- DEVOLPING AND PLANING A GREENHOUSE
1. This will be used thought the semester and will be added to as more
material is covered.
2. Students will be divided into groups
3. Poster board will be given out
4. Groups will be asked to choose a style of greenhouse that they would like
5. The choice will not be able to be changed and the area that the greenhouse
is and the plants that will be grown is important
6. Groups will choose the types of plants that they would grow in the
greenhouse
7. Groups will draw out their greenhouse choice, an exterior and interior
view
8. Groups will be asked to write in a couple of paragraphs what they have
chosen and their reasoning
9. Put the poster boards away that are finished
FRAME TYPES
7. Wood
 Good
 Attractive
 Traditional

Bad



Expensive for treated wood
Easily Rotted
Heavy
8. Steel

Good
 Inexpensive



Bad



Strong
Can be galvanized
Very Heavy
Rusts
Needs Some treatment(Painted)
9. Aluminum Alloys
 Good
 Non corrosive
 Low maintenance

Bad


Expensive
Lower retention of heat
GREENHOUSE GLAZING
10. Polyethylene


Most Common
Cheapest form of cover
11. Glass


Best light transmission
Most expensive
12. Rigid Structure Sheets



Expensive
High impact resistant
Weather resistant
13. Continue Activity- DEVELOPING A GREENHOUSE
1. Have the students get into their groups and get their plans
2. Have them discuss the choice in style and well as the other decisions that
they have made
3. Next the students need to decide what they will build their greenhouse out
of.
4. After the decision is made the students need to write a paragraph or two on
why they choose the materials that they did.
VII. Summary
A. What are styles different styles of greenhouses?
B. What are the some of the advantages and disadvantages of the various styles?
C. What are some of the different framing materials used in building a greenhouse?
D. What are some of the advantages and disadvantages of each?
E. What is glazing?
F. What are the different glazing materials used on greenhouses?
G. What are the advantages and disadvantages of the different glazing material?
H. What are the differences in a cold frame and hotbed?
VIII. Evaluation
Student will have to turn in their written reasons for the chooses that they have made so
far and justify all of their choices. Also they will turn in their drawings/plans for their
greenhouse.
IX. Handouts