Greenhouse Vegetable Production

2. Greenhouse falls within an large range of definitions
from simple hoop house made from PVC to
sophisticated automated facilities.

3.  Small family farms with 2500-10000 sq. ft.
 A few with multi-acre facilities
◦ Often operate off secondary energy system
 Industry physical sizes
◦ U.S.- 800 acres
◦ Mexico – over 450 acres
◦ Cananda – over 1600 acres
 Grew at rate of 20% in the 1990’s due to innovation in greenhouse
technology increasing increase yields near 100%
◦ Holland – over 11000 acres

4.  Tomatoes leading greenhouse crop
◦ European cucumbers
◦ Lettuce
◦ Peppers
◦ Herbs
 Leading states
◦ California
◦ Florida
◦ Colorado
◦ Arizona
◦ Ohio
◦ Texas
◦ Pennsylvania

5.  Consumer demand
◦ Greater taste
◦ Fewer pesticides
◦ Local and fresh
◦ Local community support
 Year-round production is key
◦ Either 1 or multiple crops
 Niche markets
◦ Organics
◦ Early season
◦ Out of season

6.  Over supply will drop value
◦ When your niche market becomes mainstream
 Must diversify prior to market inflation
 Energy and labor greatest expense
◦ Beside initial cost

7.  Solar greenhouse are greenhouse used capture the
energy from light
◦ Popular with small-scale growers
 Composting greenhouses use heat from compost
◦ Generates heat and Co2
◦ Rarely done
 Animal-Heated greenhouse rely on animal production
for heat and humidity
◦ Plant production often secondary
◦ Heat on average of 8% increase
◦ Some Risk

8.  Same requirements as “conventional” organic crops
◦ No synthetic pesticides, fertilizers,
 Little difference between “convention” greenhouse
technology and practices
◦ Main differences are pest control and fertility

9.  Must use several ingredients to provide full nutrition
 Often a protein based product for NPK and sea kelp or
seaweed for trace and micronutrients
 With the use of tea’s and soluble products, fertigation is
very labor efficient and easy to apply
◦ Generally used with low flow irrigation methods
◦ Are known to cause clogging

10.  Easier to adapt to for “conventional” organic growers
◦ Already familiar with soil-building
◦ Amendments are used to feed soil, not directly to the plant
needs like hydroponics

11. Cover Crops
 Perfect for rest-periods to rejuvenate soil
 Different cover crops and help add different qualities to the soil
◦ Increase microbiology
◦ Add depleted nutrients like nitrogen
◦ Increase organic matter
Weed Control
 Hand
 Mechanical
 Soil solarization
 Mulching – Fabric, plastic, organic matter
 Poultry
Soil Disinfection
 Solarization
 Steam
 Electrical heat
 Biological control

12.  Generally higher yields then soil culture
 Easier control of disease and insect
◦ Most pests are soil-borne
 No reliance on healthy soil
 For a new operation it may take time to enhance soil
quality
 Grower must provide 100% of nutritional needs
◦ Both a benefit and a liability

13.  Polyethylene bags or “slabs”
 Often fed with liquid fertilizers
◦ Using drip and low-flow irrigation
◦ Can pre-mix media with compost or other amendments
 Popular media’s include:
◦ Coco
◦ Moss
◦ Vermiculite
◦ Perlite
◦ Rockwool
◦ A mixture of any

14.  Well suited for vine crops
◦ In greenhouse production, each vine has the ability to produce
large amounts of product over an extended period of time
 Preferred method of greenhouse vegetable growers in
the U.S.
 Easy to establish and manage
 Excess fertilizer can leach out of bags and contaminate
soil underneath and downstream
 For organic production
◦ Only certain media and potting mixes are allowed
◦ Only certain liquid fertilizers are allowed: Tea’s, fish emulsion

15.  Also known as “stackers”
 Many different variations
◦ Bags hung from wall
◦ Plastic and Styrofoam containers stacked on top of each other
 Supply liquid fertilizer from to plant site, liquid trickles
down to lower plant site
 Popular with vine growers

16.  Similar to bag culture
 Set-up process
◦ Bails of hay are soaked with
tea or liquid fertilizer
◦ When manure/ compost tea
cools, bale is topped with
compost potting mix for
transplants
 Wheat straw bales have
shown best results

17.  Usually used for sprouts
 1-3” of potting mix over plastic
◦ Some micro-greens/sprouts are grown on capillary mats
 Generally grown on heat mats or heat tubes in rooting
zone

18.  Liquid hydroponics and aggregate hydroponics
 Bag culture is often a form of hydroponics
 3 main approaches
1. Soluble organics (hydro-organics) – relies on soluble
nutrients
2. Aquaponics – Integration of fish culture
3. Bioponics – A hydroponic system which relies on micro-
organisms to derive nutrients of organic fertilizers

19.  Most popular systems include:
◦ NFT
◦ Aeroponics
◦ Flood and Drain
◦ Re-circulating bags or slabs
◦ Raft
 Re-circulating or run to waste

21.  You must keep in mind the cost of equipment and the
costs to operate the equipment
 If you’ve identified a high-value niche market, the
more you produce the less valuable the product is.
(Supply and demand)
 This should be considered prior to investing in the
greenhouse

22.  Introduction of bee’s
 Seed varieties specifically for the greenhouse grower
◦ Often more compact plants
 New findings in biological control
 Greenhouse coverings
 Monitoring and computerized equipment

23.  Most crop production research is based on
“conventional” crop production
 Niche markets and out-of-season crops have the most
potential
 Easy to adapt soil-based greenhouses to organics
 Soilless culture can also be organic