Greenhouse Management Unit 1

Why a Greenhouse? To grow crops out of season To grow crops not adapted to the locality To speed up the growth of crops

What are commercial greenhouses used for? 1. Fresh flowers-flowers which are cut from the plant prior to sale (roses, mums, carnations, etc.)

2. Flowering Plants- flower bearing plants which are sold in a pot (chrysanthemum, etc.)

(Ivy, Rubber Trees, Ferns, etc.) 3. Green Plants- (foliage plants) - plants sold in a pot and valued more for their foliage than their flowers (Ivy, Rubber Trees, Ferns, etc.)

(Vegetables, Impatiens, Marigold, etc.) 4. Bedding Plants - young plants sold for planting around the home (Vegetables, Impatiens, Marigold, etc.)

5. Vegetable Production-grown to maturity in a greenhouse (Tomatoes, Lettuce)

6. Woody Ornamental Propagation Reproducing more plants such as: azalea, forsythia, gardenia, etc.

Terms Greenhouse – a structure that is covered with a transparent material that allows sufficient sunlight to enter for the purpose of growing and maintaining plants.

Future of the Greenhouse Industry Growing demand for greenhouse crops Expect increased production of green plants, flowering plants, bedding plants Increased awareness of interior & exterior landscapes Potted plants are competitive on a more local basis due to difficulties and expense of long distance transportation

What role do greenhouses have in the U.S. and in agriculture? Variety of products with many uses Employment Opportunities Economy- Sell almost $20 BILLION in floriculture products/ year Fulfill an emotional need in people

Main Careers in Greenhouse Management Basics Grower Wholesaler Retailer How do these jobs differ?

Careers…. 1. Grower Produces crops for sale to wholesalers Has expertise in producing one or more crops (like poinsettias or chrysanthemums) Generally do not market or advertise

2. Wholesaler Sells a wide range of crops and products to retail businesses Serves as a supermarket for the retailers to buy supplies

3. Retailer Sells products to the general public Location is important for marketing Includes many types of businesses Florist Shops Retail Greenhouses General Retail Stores

More Careers Flower Grader Horticulturist Plant Taxonomist Floral Shop Operator Plant Geneticist Plant Nutritionist Plant Pathologist Plant Scientist Greenhouse Manager Plant Breeder Pest Control Technician Certified Seed Grower Agricultural Journalist Magazine Writer Beekeeper Marketing/Advertising Manager Purchasing Manager

Basic Greenhouse Styles

BASIC GREENHOUSE STYLES BASIC STYLES EXAMPLES OF GREENHOUSE USES BASIC GREENHOUSE COVERINGS COMMON FRAMING MATERIALS

DREAM GREENHOUSE

A. BASIC STYLES EVEN SPAN GOTHIC ARCH QUONSET RIDGE AND FURROW LEAN-TO COLD FRAME

TERMS TRUSSES- composed of rafters, chords and struts that support the roof

1. EVEN SPAN Greenhouse with two roof slopes of equal pitch and width Benefits: Excellent light, ventilation, and temp control Disadvantages: Wasted heat air in the gables

1. EVEN SPAN

EVEN SPAN

EVEN SPAN

EVEN SPAN

EVEN SPAN

2. GOTHIC ARCH Side walls are a short base wall of a solid material POINTED ARCH ROOF TRUSSES HAVE BEEN ELIMINATED Not as popular today Can have sidewalls Side walls are a short base wall of a solid material often cinderblocks

2. GOTHIC ARCH

GOTHIC ARCH

3. QUONSET A greenhouse with a semicircular arch that starts at ground level or on top of a sidewall (Half moon shape) Benefits: Less Expensive to construct Few shadows Disadvantage: Cannot handle as much wind and snow

3. QUONSET

QUONSET

QUONSET

QUONSET WITH TOP VENT

4. RIDGE AND FURROW Several greenhouses connected along the length of the eaves Benefits: Large interior areas Reduced heat loss Less expensive construction Disadvantages: More difficult to control pest and temperature Difficult snow removal

RIDGE AND FURROW

RIDGE AND FURROW

RIDGE AND FURROW

RIDGE AND FURROW

RIDGE AND FURROW

RIDGE AND FURROW

RIDGE AND FURROW

RIDGE AND FURROW

5. LEAN-TO ATTACHED TO EXISTING BUILDING Benefits: Disadvantage: USUALLY ON THE EAST OR SOUTH SIDE Benefits: Less roof support needed Heating is usually less expensive Disadvantage: Limited space

LEAN-TO

LEAN-TO

Inside Shed Lean-To

LEAN-TO

LEAN-TO Brick is an Example of Side walls (Lean-to is BOTTOM ONLY)

COLD FRAME NO HEATING OR COOLING MECHANISMS SHAPE IS OFTEN CONFUSED FOR QUONSET WILL TALK ABOUT MORE IN A LATER UNIT

COLD FRAME

COLD FRAME

COLD FRAME

COLD FRAME

COLD FRAME

COLD FRAME

Greenhouse Uses Hobby or Home Use Botanical Gardens small Lean-To or Dutch types Botanical Gardens make plants available to the public Preserve rare plants Like a “zoo for plants”

Greenhouse Uses (continued) Retail Greenhouse at home and garden centers Have displays and examples of plant uses Production House Not as eye appealing Large areas under roof More crowded spaces Entire houses and areas for a 1 type of plant

RETAIL AND PRODUCTION GREENHOUSES ARE CONSIDERED TO BE COMMERCIAL GREENHOUSES

Basic Types of Coverings GLASS FLEXIBLE PLASTIC FILMS RIGID PLASTIC SHEETS

1. GLASS ADVANTAGES: DISADVANTAGES: Excellent Light Transmission Available DISADVANTAGES: Breakable High heat loss Most Expensive

2. FLEXIBLE PLASTIC FILMS EXAMPLES: PVC- POLYVINYL CHLORIDE PVF- POLYVINYL FLOURIDE FILM POLYETHYLENE- Most Common ADVANTAGES: Inexpensive Easy to Install DISADVANTAGES: Not as durable

3. RIGID PLASTIC SHEETS EXAMPLES: ADVANTAGES: DISADVANTAGES: FIBERGLASS ACRYLIC- PLEXIGLASS POLYCARBONATE- LEXAN ADVANTAGES: Light weight Most Durable DISADVANTAGES: More expensive than flexible plastic

LEXAN USED ON OUR GREENHOUSE DOUBLE PANEL SMALL VERTICAL CELLS GOOD INSULATION DURABLE

Framing Materials 2 MAIN MATERIALS METAL WOOD MORE TOMORROW

Heating Cooling Ventilation Watering Greenhouse Systems Heating Cooling Ventilation Watering

Heating Systems Boilers Unit heaters Radiant or infrared heaters Terms: BTU

Heating Systems Things to keep in mind: Optimum temperature ranges from 60-80 degrees, depending on the plant stages Night temperature often from 50-65 degrees

1. Boilers A.K.A- Centralized Usually used to heat larger greenhouses (15,000 sq ft or more) Burns fossil fuels to create steam or heat water (coal, oil, natural gas) Pipes are used to distribute heat 2 Types Steam systems Hot water systems Provides more constant heat

Pipes

Cold Pockets

Hot Water or Steam Distribution

2. Unit Heaters A.K.A. LOCALIZED Used for smaller greenhouses Convection heat- to heat the air Distribute heat by fans or convention tubes Most burn natural gas Modine Heater is a common brand Can operate independently

Convection Tube

Holes

3. Radiant Heaters AKA- Infrared Heater Infrared Heat Lamp creates heat Radiant Heat: IR warms surfaces (plants, benches, sidewalks, soil) The warm surfaces in turn warms the air The air is not directly heated Heaters are overhead 20 to 30 feet apart Fueled on gas or electricity

4. Terms BTU (British Thermal Unit) Heat required to raise 1 lb. of water 1oF Used to measure and compare ability of heating systems

Cooling and Ventilation Systems No Cooling NATURAL VENTILATION FAN & SHUTTER COOLING FAN & SHUTTER COOLING with SHADE CLOTH Evaporative Cooling Fan & Pad (Evaporative Cooling)

SHADE CLOTHES- often used to supplement cooling/vent systems Available in a variety of colors and shading abilities

1. NO COOLING 1. Inside temperature of greenhouse can exceed 140 degrees F. 2. Plants will die within a short period of time.                                                                    

2. NATURAL VENTILATION 1. Roof vent opens to allow hot air to escape to outside. 2.  Door or other opening must be left open to provide for incoming air from outside to replace exhausted air. 3. On hot summer days temperatures can rise 20 to 30 degrees above outside temperature. 4. Recommended for mild climate areas only.

NATURAL VENTILATION

NATURAL VENTILATION

3. FAN & SHUTTER COOLING 1. Outdoor air is introduced through motorized inlet shutters. 2. Hot air is exhausted by exhaust fans. 3.Temperature inside house can be maintained within 10 degrees of outdoor temperature. 4. controlled by thermostat.

FAN & SHUTTER COOLING

SHUTTERS AND FANS

SHUTTERS AND FANS

FAN & SHUTTER COOLING

4. FAN & SHUTTER COOLING with SHADE CLOTH Similar to fan & shutter cooling Differences: 1.  Shade cloth is placed over exterior of greenhouse or suspended from wires placed on inside. 2. Temperature inside house can be maintained within 3 to 4 degrees of outdoor temperature

FAN & SHUTTER COOLING with SHADE CLOTH

5. Evaporative Cooling 1. Outdoor air is cooled by Evaporative Cooler (located outside) and discharged into greenhouse. 2. Hot air is exhausted through outlet shutters which operate automatically 3. Temperature inside house can be as much as 10 to 15 degrees cooler than outdoor temperature. 4. controlled by thermostat.

Evaporative Cooling

EVAPORATIVE COOLERS

6. EVAPORATIVE COOLING (Fan & Pad) 1. Outdoor air is drawn through pad cooling system located on one end wall of the greenhouse.  This cool air enters into the greenhouse. 2. Hot air is exhausted by fans mounted on the opposite end wall of the greenhouse. 3. Temperature inside house can be as much as 10 to 15 degrees cooler than outdoor temperature. 4. controlled by thermostat.

EVAPORATIVE COOLING (Fan & Pad)

EVAPORATIVE COOLING (Fan & Pad) Water Tank With pump

EVAPORATIVE COOLING

SHUTTERS AND FANS

D. IRRIGATION Drip irrigation Mist nozzles Fertilizer injectors Automatic Controls Solenoid valves

DRIP IRRIGATION (tubes)

DRIP IRRIGATION

MIST NOZZLES

MISTER (FOGGER)

FERTILIZER INJECTORS SLOWLY ADD FERTILIZERS TO IRRIGATION WATER, AT A SET RATE

IRRIGATION CONTROLS Solenoid Valves Help control flow rate

Examples of Greenhouse plants