Alternative Production - Season Extension Methods; Gardening Guidebook for Missouri www.scribd.com/doc/239851313 ~ Master Gardeners, Missouri State University~ For more information, Please see websites below: ` Organic Edible Schoolyards & Gardening with Children = http://scribd.com/doc/239851214 ~ ` Double Food Production from your School Garden with Organic Tech = http://scribd.com/doc/239851079 ~ ` Free School Gardening Art Posters = http://scribd.com/doc/239851159 ~ ` Increase Food Production with Companion Planting in your School Garden = http://scribd.com/doc/239851159 ~ ` Healthy Foods Dramatically Improves Student Academic Success = http://scribd.com/doc/239851348 ~ ` City Chickens for your Organic School Garden = http://scribd.com/doc/239850440 ~ ` Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica http://scribd.com/doc/239850233 ` Simple Square Foot Gardening for Schools - Teacher Guide = http://scribd.com/doc/239851110

1. 1/5/2014
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Alternative Production:
Season Extension Methods
• Freezes vs. Frosts
– Advective Freezes
• Strong Winds Bring Colder Air
• Sky May Be Cloudy or Clear
– Radiation Frosts
• Clear Skies & Calm Winds During Night
• Higher Risk of Frost With Low Dew Point
Extend Growing Season
• Plasticulture
• Plastic Mulches
• Floating Row Covers
• Low Tunnels
• High Tunnels
• Cold Frames
• Hotbeds
Plasticulture
• Integrated System
– Plastic Film
Mulches
– Drip Irrigation
Tape
– Row Covers
– Low Tunnels
– High Tunnels
Plastic Mulch
• Numerous Benefits
– Earlier Crop Production
– Higher Yields
– Cleaner Produce
– Efficient Use of Water & Fertilizers
– Reduced Erosion
– Potential Decrease in Diseases, Insects
– Fewer Weeds
– Reduced Soil Compaction
– Opportunity for Double or Triple Cropping
• Disadvantages
–  Costs & Management Time
– Removal From Field & Disposal
• Machines Expensive
• Few Recyclers
– Dirt on Plastic
– UV Degradation
– Cost to Collect & Sort
– Lack of Reliable End-Use Markets
• Used Commercially on Veggies Since Early
1960s
• Helps Growers in Northern & High-Altitude
Climates Harvest Summer Crops
• Requirements for Success
– Level Beds
– Tightly-Laid Plastic
– Drip Irrigation
• Restrictions for Certified
Organic Growers
• Many Colors, Weights, Sizes
• Black Most Common
– Suppresses Weed Growth
– Reduces Soil Water Loss
– Increases Soil T
– Improves Veggie Yield

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• Clear
– Allows Greater Soil Warming
– Used in Cooler Regions of U.S. or for Early-
Season Production
– Weeds Grow Under Clear Mulch
• White, White-on-Black, Silver Reflecting
– Slight  in Soil T°
– Maybe Helpful When Soil T Are High
• Infrared-Transmitting
– Weed Control Like Black Mulch
– Medium at Warming Soil
– Brown or Blue-Green
• Red
– Performs Like Black
– Tomato Crops Average 12%  Marketable Yield
– If Environmental Conditions Ideal, Minimal Response
From Tomatoes
– Less Early Blight & Suppresses Nematodes
• Additional Colors
– Each Reflects Different Radiation Patterns Into
Canopy
– Increased Yield for Some Crops
– May Affect Insect Populations
• Photodegradable Film
– Similar in Qualities as Other Black or Clear
– Buried Edges Must Be Uncovered & Exposed to
Sunlight
– Not Allowed in Organic Production
Floating Row
Covers
• Lightweight
• ‘Float’ Over Most Crops
• Spun-Bonded Fabric Permeable
to Sunlight, Water, Air
• Microclimate Similar to Interior
of Greenhouse
• Protection From Drying Winds
• 2 to 8° Frost Protection
• 0.3 to 2 oz./sq. yd.
• Heavier = Greater Frost Protection
– Various Lengths & Widths
– Wider Labor-Efficient
– Can Be Laid Mechanically
– Can Weight Edges With Rebar
– Leave Slack in Cover so Crop to Grow
– Row Covers Over Bare Soil Create Favorable
Environment for Weeds
– Heavier Covers Can Last 3-4 Years
– Lightest Covers Primarily Insect Barriers
• Easily Damaged by Animals
• Seldom Reusable
• Little Effect on T° & Light Transmission Dennis Hatfield Photo
• Can Leave Covers on Most
of Growth if Crops Self-
Pollinated or Leafy
• Can Get Hot Under Covers
– Tomatoes & Peppers Drop
Blossoms if T° Above 86
• Must Remove at Flowering
for Insect-Pollinated Crops
– Can Replace After
Pollination
• Can Use Cover Removal for Hardening-Off
• Covers Removed Before Spring Crops
Mature
• Covers Remain on Mature Fall Crops
– May Result in Leaf Abrasion in Windy Conditions
– Wire Hoops or Rods
• Store away From Sunlight When Removed
From Field

3. 1/5/2014
3
Low Tunnels
• Hoop-Supported Row
Covers14-18 Inches High
• Wide Enough to Cover 1 Bed
• Growers Often Use 2 3-Foot
Wide Plastic Sheets Stapled
Together at Top for Trellised
Crops
• Similar Benefits as Floating Row Covers
– Not Permeable to Air or Water
• Slitted Row Covers
– Pre-Cut Slits for Hot Air to Escape
– Slits Remain Closed at Night to Reduce Heat
Loss
• Punched Row Covers
– Small Holes Punched About 4 Inches Apart
– Trap More Heat Than Slitted Tunnels
• Growers Often Use 2 3-Foot Wide Plastic
Sheets Stapled Together at Top for Trellised
Crops
High Tunnels
• Unheated, Plastic-Covered
Greenhouses
• Commercial Greenhouses
Cost up to $20/sq. ft.
• High Tunnels Cost as Little
as $0.50/sq. ft.
• Tall Enough to Walk in
Comfortably
• 14-30 Feet Wide, 30-96 Feet
Long
• Low Cost Way to Extend Growing Season
• Improves Profitability
• Increase Early Tomato Yields
• Lettuce Through Fall & Winter
• Higher Quality Produce
• Most Passively Ventilated Via Roll-Up Sidewalls
• End Walls Can Be Opened or Removed
Andy Read photo
• Usually No Heat
• Supplemental Heat on Cold
Nights or to Extend Season
• Usually Single Layer of Poly
Provides 1 Hardiness Zone of
Protection
• Row Covers Within High Tunnels
Provide Extra Protection
– 2nd Layer Provides Another Zone of
Protection
Andy Read Photo
• Crops Typically Grown
in Ground Beds With
Amended Soil
• Irrigation Needed
• Some High Tunnels
Erected on Skids
• Weed Control Is by
Hand or Use of Mulch
• Low Cost Drip System
• Maximize Space
Andy Read Photo

4. 1/5/2014
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Caterpillar Tunnels
• Much Less Expensive Than High Tunnel
• Can Be Up to 300 Feet Long
• Don’t Require Flat Ground
• Usually 5 to 6 Feet Tall at Center of Hoop
• Easy to Build & Move
• Provide Protection & Excellent Air Flow
• Can Exclude Insects
• Cover
– Shade Cloth
– Row Cover
– Insect Mesh
• Construction
– Make Hoops From Galvanized Steel, Electrical
Conduit or PVC
– Can Be Pushed Directly Into Soil or Placed Over
Rebar Ground Stakes
– Space Hoops 6 to 10 Feet Apart
– Tie Rope From Hoop to Hoop to Form Purlin That
Runs Length of Tunnel
– Tie Off Rope to Stakes at Both Ends
– Pull Covering Over Tunnel & Tie to Ground With Pegs,
Sand Bags or Rocks
– Pound Stakes Into Ground Between Hoops on Both
Sides of Tunnel
– Tie Ropes Across Top of Tunnel to Stakes to Hold
Covering in Place
• Winter Production Is Possible But Restricted
– Severity of Winter Weather
– What Crops Are Grown
– Availability of Supplemental Heat
• Can Be Covered With Shade Cloth in Summer
• 30% Shade Reduces Air T° 4 Degrees
• Crops That Grow Better in Cooler T°
• Sprinkler Irrigation
• Tomato Production Common
hightunnels.org
Cold Frames
• Unheated Box With Bottom Open to Soil on
Which Frame Rests
• Top Is Transparent, Removable Panel Exposed
to Sun
• Passively Protects Its Contents From Most Severe
Winter Weather
• Serves as Growing Chamber in Spring
• Uses of Cold Frames
– Hardening Off Seedlings Started Indoors, Seed
Sowing, Propagation Bed, Protect Marginally Hardy
Plants & Tender Bulbs in Winter, Store Bulbs or Plants
for Forcing
• Location
– Gently Sloping Ground, Face South or Southeast
– High End About 6 Inches Higher Than Low End, High
End Toward North, Sash Sloping Toward South,
Sheltered on North With Wall or Hedge if Possible
• Can Create Temporary Windbreak
• Construction
– Keep It Simple, Use Recycled Materials, Plan to
Complete Project in Few Hours, Keep It Inexpensive,
3x6 Feet Standard Size But Smaller OK
• Management
– Ventilation, Watering, Protection Against Extreme
Cold, Summer Shade
Hotbeds
• Similar to Cold Frames But With
Some Form of Artificial Heat
• Soil Maintained at Warm and Fairly Constant
T°
• Great for Germination of Most Seeds
• Great for Growing Wide Variety of Young
Seedling Plants
• Plants With Short Growing Season May Be
Grown in Hotbeds
• Can Serve as Cold Frame Later in Season
http://extension.missouri.edu/explore/images/g06965art02.jpg

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• Manure Hotbeds
– Dig Pit About 2.5 Feet Deep
– If Earth Walls Are Firm, No
Inside Wall Needed
– Start in Early March
– Use Fresh Horse Manure
– 4 Cubic Yards Needed for Single-Sash 6x3 Hotbed
– Pile Manure Near Hotbed
– Turn Heap Every 3 or 4 Days
– Place in Pit When Entire Pile Begins to Heat
Evenly
– Spread Evenly in 6-Inch Layers
– After 2 Feet Deep With Manure, Spread Thin
Layer of Straw Over Pile
– Add 4 to 6 Inches of Seedbed-Suitable Soil
– Insert Soil Thermometer so Mercury Extends Well
Down Into Soil
– Sash Should Remain Tightly Closed
– Thermometer Will Register High 1st Few Days
– Hotbed Ready to Use When Soil T°Cools to 75F
• Hotbeds With Wood Chips
– Wood Chips Can Be Used in Deep Frames
– Add Generous Sprinkling of Quicklime on Top of
each 6- to 8-Inch Layer of Firmly Packed Wood
Chips
– Repeat Until Depth of About 30 Inches
– Place Thin Layer or Leaves or Pine Needles on Top
to Prevent Topsoil From Washing Into Chips
– Add Soil
• Cleaning
– Yearly
– Half-Rotted Medium Can Be Mixed With Topsoil &
Sand for Use as Excellent Compost in Garden &
for Potting
• Electric
– Insulated Electric Cable May Be
Buried in Soil to Provide Uniform Heat
– Dig Pit About 12 Inches Deep
– Pit Needs to Be About 2 Feet Longer and 2
Feet Wider Than Dimensions of Frame That
Will Be Set on Top of Filled Pit
– Fill Pit With 6 Inches of Gravel
– Place Frame Directly on Bed
– Add Soil Around Outside of Frame for
Insulation
– Place Layer or Burlap or Peat Moss Over Gravel
– Spread 1 Inch Sand Over Surface
pubs.ext.vt.edu/426/426-381/426-381.html
– Lay Electric Cable on Sand in Uniform Loops
– Need About 60 Feet of Flexible, Heavily Insulated
110-Volt Cable for 2-Sash Hotbed
• 6 Feet Square
– Will Make 10 Coils Spaced About 7 Inches Apart
– Connect Ends of Cable to Thermostat
– Place Thermostat Inside Frame
• Switch Box on North Side of Bed
– Maintain Uniform Temp
• 60 – 75F Tender Plants, 50 - 60F Half-Hardy Plants, 45 -
60F Hardy Plants
– 2-Sash Hotbed Needs About 400 Watts to Provide
Adequate Heat in Zone 6 or 7
– Around 1 Kilowatt Hour/Square Yard of
Hotbed/Day
• Disadvantages of Hotbeds
– Current May Fail Due to Severe Storm or Other
Emergency
– Higher Likelihood of Damping-Off Since Plants
Growing in Hot, Humid Environment
– Plants More Sensitive to Sudden Fluctuations in
T°
– Be Careful With Ventilation & Watering
– Harden Off Plants Before Transplanting Outside