Organic Greenhouse Practices

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Organic Greenhouse Practices

• Beth Christofferson

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Overview

• Organic Program
• Container Media
• Fertilizer
• Integrated Pest Management
• Plant Growth Regulators
• The Organic Greenhouse Money-maker!?

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Container Media

• Commercial Blends
• Custom blend
• Pre-packed
• Making your own
• Experimentation
• Recipes
• Implementation

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Container Media

• Ingredients allowed
• Field or garden soil
• Must be certain it has not been treated
• Sand
• Compost
• 20-30
• Bark
• Peat Moss
• Coir
• Newspaper

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Container Media

• Alfalfa
• Kenaf
• Sawdust
• Clay
• Perlite
• Vermiculite
• Limestone

-ATTRA Potting Mixes for Certified Organic
Production
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Fertilizer

• Incorporated
• Nitrogen
• Phosphorus
• Potassium
• Soluble
• Nitrogen
• Phosphorus
• Foliar

ATTRA-www.attra.ncat.org
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Integrated Pest Management

• Always remember
• Clean greenhouses regularly (once a week)
• Check plants for pest infestations once to twice
  a week depending on susceptibility
• Quarantine incoming plants
• Screens
• Avoid over fertilization
• Allow for fallow times
• Use several small IPM releases
• If you are using a pesticide be wary of immunity
  build up

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Integrated Pest Management

• Mealy bugs
• Soft Scales
• Thrips
• Two-spotted Spider mite
• Whitefly
• Fungus Gnats
• Aphids

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IPM Mealy bugs

• The fluff
• Produce white wax and honeydew substances
• Leaf yellowing, curling and drop
• Females live about thirty days
• Citrus
• Longtail
• Management
• Washing or wiping with a cloth
• Sticky traps

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• Insecticidal soaps or oils
• Biological Controls
• Mealy bug destroyer ladybeetle (Cryptolaemus
  montrouzieri)
• Parisitoids
• Stingless wasps-Encyrtids and aphelinids

Minnesota Department of Agriculture- Biological
Control Program
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IPM Soft Scale

• Produces honeydew substance
• Leaf yellowing, drop and stunted new growth
• Adult females live attached to leaves
• Hemispherical scale
• Brown soft scale
• Green soft scale
• Management
• Washing for soft scale

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• Insecticidal soap or oil
• Biological control
• Mealy bug destroyer ladybeetle (Cryptolaemus
  montrouzieri)
• Ladybeetle (Rhyzombius lophanthae)
• Parasitoid
• Stingless wasps-Encyrtid wasps

Minnesota Department of Agriculture- Biological
Control Program
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IPM Thrips

• Makes leaves look splotchy
• Also causes rolling, blistering, discoloration,
  and at times leaf drop
• Some thrips can also carry viruses
• Management
• Sticky cards in blue or neon pink
• Weed free environment
• Light colored clothing
• Fallow period

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• Insecticidal soaps and oils, hot pepper wax, and
  garlic extracts
• Biological Control
• Green lacewing, minute pirate bug, pink-spotted
  ladybeetle, and Hypoaspis miles (predator mite)
• Parasitoids
• Thripobius semiluteus parasitizes the greenhouse
  thrips nymph
• Steinernema spp. of nematode attack soil stages

Minnesota Department of Agriculture- Biological
Control Program
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IPM Two-spotted spider mite

• Leaves look spotted/stippled and covered in
  webbing
• Feed on plants one cell at a time
• Adults can live up to 21 days
• Management
• Insecticidal soaps or oils
• Lower temperatures below 75F
• Remove weeds and other plants from near vents and
  around greenhouse

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• Biological controls
• Phytoseiulus persimilis-quick control and
  actively seeks the spider mites, prefers 60-85F
  and above 50 humidity
• Neoseiulus californicus-survives a period without
  prey and works well indoors with variable
  conditions
• Stethorus punctillum-tiny beetle that thrives in
  variable conditions
• Orius insidiosus (Minute pirate bugs)-adapted to
  conditions favorable to spider mites

Minnesota Department of Agriculture- Biological
Control Program
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IPM Whitefly

• Cause stunted growth, yellowing and reduced
  yields
• Management
• Yellow sticky cards
• Remove plants and weeds from around greenhouse
• Avoid re-infestation
• Proper disposal of infested plants

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• Biological control
• Black ladybeetle (Delphastus spp.)
• Parasitoid
• Stingless wasp (Encarsia formosa)

Minnesota Department of Agriculture- Biological
Control Program
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IPM Fungus Gnats

• General diminished plant health and stunting
• Spread plant pathogens and cause plants to be
  more susceptable to disease
• Adult females deposit up to 1000 eggs in their 7
  day adult stage
• Management
• Yellow sticky cards
• Avoid over-watering

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• Keep growing areas dry and free of weeds and
  algae
• Biological control
• Soil application of Bacillus thuringiensis
• Beneficial nematodes (Steinernema sp.), rove
  beetles (Atheta sp.), ground bettles, and soil
  centipedes
• Predator mite Hypoaspis miles

Minnesota Department of Agriculture- Biological
Control Program
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IPM Aphids

• Leaf curling, yellowing, distortion, stunting and
  death of new growth
• Honeydew
• Ants protect aphids for honeydew
• Green peach aphid
• Potato aphid
• Cotton or melon aphid
• After birth an aphid can mature in 7-8 days

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• Adult females can then produce up to 10 aphids a
  day
• Management
• Washing
• Insecticidal soaps or oils
• Biological controls
• Ladybeetles (Harmonia axyridis, Hippodamia
  convergens, and Coleomegilla maculata) , lacewing
  (Chrysopa or Chrysoperla) , predator midges
  (Aphidoletes aphidimyza) and minute pirate bug

Minnesota Department of Agriculture- Biological
Control Program
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Growth Regulator

• Reduce leggy plants
• High Intensity Discharge (HID) lamps
• Non-chemical
• Brushing
• Temperature
• Brushing
• Brush the plant tops
• Study at Cornell

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• Temperature
• Cooler temperatures slow growth
• Reduced differences in day and night temperatures

ATTRA-www.attra.ncat.org
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The Organic Greenhouse Money-maker

• Supplier of organic plugs and seed
• Reduced competition
• Commercial suppliers recommended on ATTRA
• Mountain Valley Growers, Inc.
• Greystone Gardens
• Patchwork Farm and Greenhouse
• There are many smaller businesses listed on the
  ATTRA
• Few are in or near Minnesota

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• You could transport products to customers faster
• Locally grown
• Supply to the public
• Offer starter plants of organic vegetables and
  herbs
• Houseplants!

ATTRA-www.attra.ncat.org
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Sources Cited

• ATTRA. Potting Mixes for Certified Organic
  Production. Sept 2004. ltwww.attra.ncat.orggt
• Cunningham, Neil. Biological Control Program
  Fact Sheet. Minnesota Department of
  Agriculture.ltwww.mda.state.mn.us/biocon/plants ca
  pe/default.htmgt
• Lacey, Roy. The Organic Greenhouse
  Conservatory. Newton Abbot David Charles,
  2004.
• All pictures used are from location cited on the
  page it is located, from my personal collection
  or clip art.