- 1.Season ExtensionSusan Donaldson
2. What is season extension? Increasing the growing season
ateither end, spring and/or fall 3. Why try to extend theseason?
Allow more time for crops tomature Grow different varieties Move
toward year-round productionand income potential Fresh greens in
the winter 4. Frost-free period Well define the length of a
frost-free period as the number of daysbetween the date of the last
32Ftemperature in the spring and thedate of the first 32F
temperature inthe fall. 5. Whats freezing? The National Weather
Servicedefines a freeze as occurringwhen the surface air
temperatureis 32F or below over a widespreadarea for a
climatologicallysignificant period of time (greaterthan one hour).
(U.S. Department ofCommerce, 2005) 6. How long are our
frost-freeperiods? Lots of variation among periods forthe last 100
years Some years have had frost-freeperiods of over 150
days(approximately 5 months) Other years have had frost-freeperiods
of less than 90 days. (Reno data) KEY: lots of varibility, so you
haveto watch the weather predictions! 7. Do frost-free periods
everchange? For the 30-year period of 1971-2000,the average date of
the last 32temperature in the spring was May21 while the date of
first 32temperature in the autumn wasOctober 3 (134 days). 8.
1991-2005 The date of last 32 reading wasMay 3, and the date of
first 32reading in the autumn wasOctober 19 The average length of
the frost-free period grew from 134 days(for 1971-2000) to 168 days
for themore recent 15-year period This is an increase of a
fullmonth! 9. Hard freeze A hard freeze is sometimes definedas
occurring on a date when thetemperature drops to 28F Butyou can
expect damage whentemps drop to 32F 10. CityFrost-Free DaysCarson
City90 - 116Elko57 - 87Ely 53 - 81Fallon106 - 131Lovelock111 -
140Reno 85 - 125Tonopah 107 - 147Winnemucca 75 - 107Based on
historical data indicating 90% (first number)- 121Yerington with
temperatures above50% (second number) 82 to 32F.probability of
consecutive dayshttp://www.wrcc.dri.edu/summary/Climsmnv.html 11.
Cold damage Plants lose heat faster than the air! Anything that
reflects the radiatingheat back down will prevent or atleast
greatly reduce frost formation(for example, clouds) 12. Season
Extension:Start with cultural practices Site selection and
microclimates Soil and moisture content Windbreaks and shade
Irrigation Cultivar selection Transplants 13. Take advantage
ofmicroclimates Some areas around your propertywarm up faster in
the spring, staycooler or warmer in the summer, orare protected
from the wind South-facing slopes will be warmer Cold air settles
into valleys 14. Site selection #1: Hours of sunlight Prevailing
winds 15. Windbreaks and shade At right angles to prevailin g
winter winds Consider effect on sunlight 16. Shade fabrics 17.
Shade fabric Creates a cooler microclimate tohelp prevent bolting
and bitterness Faster germination of cool-weatherfall crops Shading
30 -50% in midsummer canlower leaf temps by 10 degrees ormore 18.
Managing moisture Plants under drought stress can bemore
susceptible to cold damage Water holds warmth and releases itslowly
Sowater before frost is expected 19. Alter soil temperatures Use
clear plastic mulch to warm soil inspring and retain extra heat in
fall Cover the edges of the plastic with soilto anchor it in place
Temps increase by 8 to 14 degrees to adepth of 2 inches and 6 to 9
degrees toa depth of 4 inches 20. Mulch to insulate plantsOrganic
mulches such as straw alsodecrease radiated heat and
conservemoisture, preventing cold (and hot)extremes 21. Choose
hardy crops Start and end with cold-hardyvegetables that tolerate
frost Look for short-season varieties Other varieties are
speciallyadapted to growing in long, hotdays, extending your
growingseason into the summer (ex. slowbolting lettuces) Read seed
packets and catalogdescriptions 22. Spring crop transplants Start
plants early Start seeds of tomatoes, peppers,and eggplants 8 weeks
early Start seeds of cole crops about 4 to6 weeks early Start vine
crops 1 week early 23. Fall crop transplants Start plants for
late-season crops inlate summer Seed a second season of
quick-maturing vegetables, such as snapbeans, peas, greens,
radishes, colecrops, and turnips later in theseason Grow
cold-tolerant species in thefall 24. Examples of late-seasoncrops
Kale Collards Lettuce Spinach Mustard greens Arugula Broccoli
Broccoli rabe Mache BeetsLettuce, kale and rabe Peas 25. Winter
harvest Decreasing levels of light infall/winter slow plant growth
tonear-dormancy Lowest light in December andJanuary Many
cold-weather crops must beharvested by the end of fall 26.
Vegetable planting dates Planting dates depend upon theplant
cold-hardiness. Semi-hardy vegetables can beplanted two to four
weeks beforethe average last killing frost date ofMay 15, or in
cool fall temps 27. Vegetable planting dates Plant frost-tender and
cold-sensitive vegetables after the lastfrost date Buy transplants,
or start from seedindoors from mid-March throughmid-April Earlier
transplanting can be donewhen hotcaps, row covers or
otherprotection is used 28. More tips Grow cold-tender herbs,dwarf
fruittrees, etc. incontainers thatyou can moveindoors 29.
Usingprotection 30. Protect from early and late frosts Cover early
and late seasonplantings with mini-greenhousesmade from clear
plastic, oldwindow sashes set on hay bales, orfabric row covers
Vent the covers on warm days toprevent excessive heat buildup 31.
Use hot capsin spring Need to ventthem Works forsmall plants Blocks
somelight 32. Light penetration not good;minimal frost protection
33. Walls of Water Good frostprotection butexpensive 34. Fall
freeze protection Use old sheets, blankets, draperies,etc. Cover
plants before sundown totrap heat 35. October 5-9, 2011Elevation
5400 ft 36. Fall freeze protection Extend the covering all the way
tothe ground so cold air cant seep in Put in place before sundown
Especially useful for the first fewfrosts when warmer weather is
thenexpected 37. More tips Cover hardy root crops with a 6-
to12-inch-thick layer of straw or otherorganic mulch in fall to
prevent thesoil from freezing. Harvest as needed throughout
thewinter. 38. Row covers Agribon, Reemay,Harvest Guard, etc. Come
in differentweights Can provide 3to 5 degrees offrost protection
39. Row covers Warm and speed the growth ofseedlings in spring Slow
the evaporation of soil moisture Protect plants from wind, heavy
rain,and hail Heavier fabrics provide more frostprotection but
block more light 40. Row covers Keep pests off plants but need
toremove covers for insect pollination Protect late summer crops
from fallfrost Protect crops from hot temperaturesand burning sun
rays Must anchor with soil, wood, rocks,etc. 41.
ClochesLightweightPortableReusable 42. Cold frames Can provide 5 7
degrees ofprotection Can be used in the spring to startplants or in
the fall for cold-hardycrops Use old windows or glass doors tomake
your own No standard size; keep widthnarrow enough that you can
easilyreach across 43. Can add black containersfilled with water to
store heat for the night 44. Cold frames Dont use wood treated
withpreservatives! Slope the lid to the south Place on south side
of house 45. Cold frames Provide for ventilation of excessheat when
temps rise above 55degrees Cover to protect against freezing,or
stack straw bales against theframe 46. Cold frame tips Ventilate on
warm days Checktemperatures with a thermometer Protectduring
freezing weather: Remember that cold frames give only 5-10 degrees
of warmth. 47. More cold frame tips Water: make sure plants arent
getting too much or too little water. Hardening plants: open the
lid of your cold frame longer and longer each day 48. Low
tunnels:Hoop-supported row covers 49. Benefits of low tunnels About
five to six weeks earlierproduction in the spring Several weeks
later production inthe fall Some protection from insects
andforaging animals Some protection from extremeweather conditions,
such as strongwinds, hail or frost
http://simplegoodandtasty.com/2010/05/25/tunnel-farming 50. Tips
for low tunnels Use UV-stabilized tubing Dont expect protection
from hardfreezes Plan for access and ventilation 51. Building
materials to construct one minitunnel for 40-inch by 30-foot raised
bedQuantityItem Description Unit Price Total200 feet1/4-inch nylon
rope$0.08/ft $16.001,8-ft by 38- 6-mil greenhouse poly
$0.13/sq$39.52ft sheetfilm ft1/2-inch sch 40 PVC80 foot$0.22/ft
$17.60pipe20 foot 1-inch sch 40 PVC pipe$0.44/ft $8.80442-inch wood
screw$0.05$2.202 3/8-inch by 2-foot rebar $0.75$1.502 Eye
screw$0.50$1.00*Prices may vary depending onTotal $86.62location,
etc.http://www.noble.org/Ag/Horticulture/RaisedBedGardening/mini_tunnel.html
52. High tunnels (aka hoophouses) Big enough to walk into Size them
to meet your needs Plant in-ground or in raised beds Does not have
an added sourceof heat or ventilation Can extend the season
throughthe winter by up to three zones, ora month in the fall 53.
Orient in an east-west direction tomaximize sunlight, but also
consider 54. Structural elements Can be mobile or fixed in place
End walls are most important tostrength Can incorporate an opening
forventilation in the end walls Hoops no more than 4 feet apart
Peaked-roof (vs. U shape) strongerin snowy climates 55. Structural
elements Use a center support to increase stability Use 6-mil,
greenhouse-grade, UVstabilized polyethylene Roll-up sides allow for
ventilation 56. How to Build a High Tunnel
(video)http://www.youtube.com/watch?v=am1Tso2l3kcAlso
seehttp://www.extension.org/pages/18356/low-cost-high-tunnel-construction
57. Minnesota study On average, tunnel vegetables suchas lettuce,
tomatoes and cucumberswere harvested about six weeksearlier than
those grown in the open,while peppers were ready nearly tenweeks
ahead. Many of the tunnel plants produced asmuch as double the
output of theoutdoor crops 58. What about winds? High tunnels
placed perpendicular toprevailing winds typically receive themost
damage, so consider placingparallel The best protection against
uplift is toensure that posts are driven at least24 inches into the
ground Use stretch cord over the top of theplastic from one side to
the other,every fourth rib 59. What about snow? A high tunnel built
from ribs of 20 footpipe bent to create a 14 foot wide X 6foot high
structure will withstand onlyabout 10 psf This is about 2 inches of
water assnow Might be as little as one foot of snow 60. More tips
for dealing withsnow Use a center roof rib Orient the structure so
prevailingwinds blow the snow off the hightunnel Remove the plastic
in the winter if notunder production Brush off snow using a
long-handledbroom (carefully!) 61. NRCS High Tunnel
PilotProjectEligibility Requirements: To qualify, the applicant
must: be an agricultural producer install the high tunnel(s) on
cultivated landwhich includes existing gardens, irrigatedhayland
and irrigated pasture have raised or sold $1,000 worth
ofagricultural products
http://www.nv.nrcs.usda.gov/programs/NV_high_tunnels.html 62.
GreenhousesWalk-in, permanently placed The most expensive solution
Usually have venting and heatingsystems (requires energy inputs
butgives more control) In some areas, can be used yearround Can add
mass for thermal storage(water barrels, etc.) 63. Do your homework
Many types on the market Many plans available as well Look at the
alternatives beforeinvesting Can use to insulate your house
whenattached Consider a solar greenhouse 64. Bozeman, MT 65.
GreenhousesWalk-in, movable Less expensive Can be disassembledand
stored away whennot in use Usually used one to twomonths before the
lastfrost in the spring. 66. Whatever you do Keep good records!
Consider a journal that includesvarieties, dates planted,
datesmatured, freezes, etc. Nurture your soil with lots of
organicamendments Keep a map of what was plantedwhere 67. Crop
rotation: varyingfamilies 68. Why rotate crops? Breaks the cycle of
disease and pests Helps to maintain adequate nutrients Can help
improve soil structure(alternate deep-rooted plants
withshallow-rooted plants) Can decrease costs 69. Considerations in
crop rotationschemes Heavy feeders: leafy veggies,brassicas, corn
Soil conserving/improving: legumes(peas and beans) Lighter feeders:
bulb and root crops,many herbs 70. Simpler
rotationLegumesNightshadesBeans TomatoesPeasPeppersLentils
PotatoBrassicasCucurbitsBroccoliCucumbersCabbage
SquashesCauliflower Melons 71. Another simple rotation Root Legumes
crops, and onions brassicasSweetNightshadescorn,-cucurbitstomatoes
and peppers 72. End-of-season maintenance Clean up! Remove dead
vegetationand windfalls, compost healthymaterial. Remove fallen
fruit and deadleaves to decrease pest problems. Think about cover
crops to enrich andstabilize soil (winter rye, triticale) 73.
End-of-season maintenance Enrich garden beds with compost ormanure;
add mulch or leaves; thinkabout nutrient needs for your
specificcrops Collect dried seed from openpollinated flowers &
veggies Clean out cold frames for winter use 74. End-of-season
maintenance Clean and oil lawnmower, othergarden equipment and
tools beforestoring for winter Take equipment in to be
sharpened(mower blades, pruning equipment) Drain and store hoses
carefully toavoid damage from freezing Clean, sand and oil garden
toolsbefore storing them for the winter 75. Questions?Sue
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