Tips for Tunnels of all Types Vern Grubinger December 10, 2014
Tips for Tunnels of all Types
Vern Grubinger
December 10, 2014
plastic mulch row covers
low tunnels caterpillars field tunnels
hoophouses high tunnels greenhouses
Seasonal
structures
• low tunnels
• caterpillars
• field tunnels
(Haygrove)
Year-round
structures
• hoophouses
• high tunnels
• greenhouses
low tunnels ~$0.50/sq. ft.
Johnny’s
Seeds
“quickhoop”
Bender
½‘’ conduit
+ Agribon
overwintering kale, mustard, onions, spinach etc.
planting date has an effect on yield
Ruth Hazzard, Univ. of Mass. and Becky Sideman, Univ. of NH
varieties differ, too (overwintered onions)
caterpillar tunnels ~ $1/sq. ft.
Windflower Farm in upstate New York
Oriented so ends face the prevailing wind.
plastic must be removed before winter
Windflower Farm crops and structures
Crop Low Tunnel Caterpillar Hi Tunnel
Tomato XX (trellis) XXX
Pepper X XX
Eggplant X XX
Cucumber XX XX (trellis) XXX
Melon XX XX (trellis)
Squash XX XX
Spring Greens XX XX
Fall Greens XX XX
Winter Greens XX
Spring Onions XX XX
field tunnels aka Haygroves ~$1/ sq. ft.
single or multi-bay >1 acre
wind is a concern with
any 3-season structure
keeping the rain off…
season extension…
manual ventilation required
hoop house ~ $1.50/sq. ft.
low height, quonset shape, no sidewall vents
declining popularity:
high humidity
poor ventilation
low head room
high tunnels ~$2/sq. ft.
gothic, roll-up sides, plastic, drip
Ledgewood Farm frame with gothic peak, high sides
supplemental air, ground heat?
FarmTek quonset high tunnel
home made wood frame – Pete’s Greens
plastic greenhouse ~$10/sq. ft.
tunnel vs. GH
electricity
heat
foundation?
size?
high side and ridge vents (poly-vent tubes)
HAF, bottom and air heat, zoned drip
tomatoes in Poly-Tek greenhouse
‘winter’ greens in Harnois greenhouse
tight, low surface:volume, high sides and peak
Rimol greenhouse
wide span, endwall peak vents, tractor access
Rimol automated roll up sides
glass greenhouse ~$25+ / sq. ft.
Longwind Farm, organic GH tomatoes
heat pipes/cart rails, environmental controls
Full Bloom Farm, organic basil
rolling benches, potfillers, lighting
design for your crops, markets, budget
long season ‘tropical’ crop
‘season extension’ of perennials
unheated spring-planted crops
unheated ‘winter’ crops
transplants on heated slab
Key Considerations
• Site
• Structure
• Environmental Controls
• Soil / Crop Nutrition / Water
• Pests
• Labor / Management
• Costs and Returns
got drainage, compaction?
perimeter drainage
space for snow, mowing, access, expansion?
worst case snow, ice, and/or wind?
soil fertility and crop nutrition
‘super-charged’ soils
saturated media test vs. field soil test:
soluble vs. reserve nutrients
0
200
400
600
800
1000
1200
1400
1600
1800
2000
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 69 71 73
K in greenhouse ‘soil’ 75 samples 2008-09
sanitation is a key to pest management
No weeds inside houses
Well, almost
no weeds...
mow around houses
hoses off the ground
monitoring is another key to pest management
heat rises
fans pull air with the least resistance
furnaces fail,
fuel runs out!
heat-activated vent,
temperature alarm
tunnel edges take time to weed
why waste fuel?
small cracks matter
energy conservation
perimeter insulation
bench heat, insulated knee walls
use step controllers or accurate thermostats
renewable fuels like shell corn, wood pellets
solar hot water + biomass heat
if you’re a logger in the winter…
balance cost, Btus, materials handling, reliability
www.uvm.edu/vtvegandberry