Technical Assistance Elluminate tech support Jennifer Nelson nelson35@illinois.edu 423-298-6986 (call or text) Jennifer can be contacted during the presentation for problems with Elluminate
A Harvest For All Seasons Christopher Konieczka Extension Educator, Local Food Systems and Small Farms Livingston/McLean/Woodford Unit cmkonie@illinois.edu Kyle Cecil Extension Educator, Local Food Systems and Small Farms Henderson/Knox/McDonough/Warren Unit cecil@illinois.edu
Get Involved! How did you hear about our program? A Local Extension Website B Illinois Small Farms Website C Newspaper/TV D Other (write it in the chat box, please)
A Harvest For All Seasons Fall and Winter Vegetable Production Four Keys To Success
The Four Keys Use of cold tolerant crops Timely plantings Use of multiple harvest crops Protection of the crop
How can plants freeze and survive? Repeated freezing and thawing of most plant cells disrupts them because of the repeated formation of sharp ice crystals. During the coolest weeks of the winter, leaf water content decreases in cold tolerant plants while soluble sugars increase substantially. Resulting in increased freezing tolerance.
Understanding heat and light Heat-comes from solar radiation and from the earth s ambient temperature. Plants need combinations of both to grow and produce. Trap and store the heat
How are conditions different? Summer: Excess of light and heat Management is geared to keeping plants cool and not exceeding critical temperatures Fall/Winter: Light and heat are limited must be captured and used efficiently. Maintaining a growing environment (heat and light) is the goal
Angle of the sun s rays The more angled the roof-the more light you will intercept. The apparent path of the Sun across the sky. Note how much higher the Sun is in the sky in mid-summer! Credit: Stern (2001) NASA
Light Management Day length at 41 Latitude late December is about 9 hrs. Day length at same latitude in late June is about 16 hours. Question: Does this mean there is one-half the light in Dec versus June?
Light Management Answer: No In addition to decreasing day length in winter/fall, light intensity is drastically decreasing as well. Need to consider the Daily Light Integral (DLI)
Daily Light Integral (DLI) Measured in moles per square meter per day Example: DLI can range from 2.5 to 50 moles per day-a factor of 20! (Bierbaum, 2004) A cloudy day in December might experience 5% of the light that a sunny day in June might have. Plant growth needs to take place earlier in the season!
D.L.I continued When D.L.I. drops below 10 for the day plant growth slows considerably (December/January) Remember, greenhouse plastic can reduce the light as well as will row covers. (from Bierbaum et.al 2004)
Time Out! Are you currently producing in high tunnels? A - Yes, 4 season high tunnel production B - Yes, 3 season high tunnel production C - Tunnel is up, but not in use D - No, not yet...
Temperature Management Average Daily Temperature-ADT For cool season crops, the temperature at which there is little or no growth is 32 to 35 F An example: If the range of base temperature to optimal temperature is 25 degrees for each 5 degrees increase in ADT the plants will grow about 25%
Temperature Management Soil temperature will be influenced by: Amount of sunlight Amount of soil moisture Air temperature Soil temperature is a good indicator of overall energy(temperature) in the high tunnel.
Temperature, continued If the soil is dry, it is likely to be as cold as the temperature just above the soil. Dry soil is less dense. But if the soil is moist, the water will freeze when the temperature falls to about 32 F. As water freezes, some heat is released, sufficient heat to keep the temperature from falling below 32 F as long as there is still some water transforming to ice. It is not uncommon to have the soil temperature fall rapidly to 32 F and then hold at 32 F for two or more days (nights) of air temperatures below 20 F.
St. Charles Research Center, Univ. of Illinois
Structure effect on thermal performance Layer(s) of poly..1 or 2? Insulated perimeter Insulated end walls Rule of thumb: 1 layer poly=1 growing zone
Structures, continued Add foam board insulation material from the soil surface down to a 12-18 inch depth around the perimeter of a greenhouse or high tunnel. This can significantly conserve heat and keep the soil along the walls 10-20 F warmer.
Structures, continued Insulated endwall reduces heat loss
Keep soil exposed Do not use mulch Do not use plastic You want the soil surface exposed to sunlight during the day.
What to Plant? Cold tolerant crops Late fall, winter, or overwintered crops? Balance hardiness and marketability Mostly extending the harvest season http://planthardiness.ars.usda.gov/phzmweb/#
What to Plant? Greens lettuces, spinach, Asian greens, arugula, kale, chard, corn salad (mache) Roots carrots, beets, turnips, parsnips, radishes Alliums leeks, green onions Use seed catalogs to help determine best varieties http://www.johnnyseeds.com/
What Will You Do? What crops do you plan to grow during winter in high tunnel(s)? A Greens (lettuces, spinach, kale, etc.) B Roots (beets, carrots, turnips, etc.) C Alliums (onions, leeks, garlic, etc.) D Herbs (parsley, cilantro, etc.)
25 F - Napa cabbage, endive, mizuna, green onions, bok choy, 22 F - Arugula, tat soi 20 F - Beets, celeriac, mustard greens, Italian parsley, radishes, turnips 15 F - Russian kale, some lettuces, cilantro 10 F - Chard, carrots, collards, daikon, rutabaga, leeks, largeleaf spinach 0 F - Chives, corn salad, parsnips, salsify, some spinach, Jerusalem artichoke What to Plant?
What to Plant? Varietal Selections for Winter Harvest Cabbage - Savoy, January King, Blues Chard - Bright Lights, Rainbow green is hardier Kale Red Russian Pak Choy - Prize Choy, Joi Choi Pak Choy, Mizuna - Ruby Streaks Endive Perfect, President Green Onions Evergreen Winter Hardy White, White Lisbon Spinach - Space, Regiment, Covair, Tyee, Olympia, Bloomsdale Savoy Lettuces - Lollo Divino, Red Sald Bowl, Winter Wonderland, Revolution, Rouge d Hiver Carrots - Danvers, Oxheart, Napoli Beets - Red Ace, Albina, Verduna, Lutz Winterkeeper Leeks - Alaska, Durabel, American Flag, Bulgarian Giant, Laura, Tadorna
What to Plant? Experiment! Do your own research Try other varieties (clearly marked) Use outdoor cemetery patch for varietal selection Find niches within the winter produce niche
When to Plant? Succession plantings beginning in late summer Plant enough volume to carry through slow regrowth Mid November to early February growth is very slow Expect # of days to harvest to increase (14-28 day margin) Determine when you want to harvest a crop and count backwards
When to Plant? Average Frost Free Period in IL, April 15 October 15 (varies by location) Plants can be sown outdoors and transplanted into hoops Weeks before 1 st frost to plant some crops: 10 weeks - beets, cabbage, daikon, leeks, lettuce, turnips, rutabaga 8 weeks - winter radish, fall spinach 7 weeks - kale 5 weeks - spring spinach
Planting Considerations Balance space, crop size, and disease management Plant rows more densely than outside production Raised beds can warm soil more quickly Plant seeds deeper than in spring (soil is warm, prevents drying) Begin with good tilth, avoid compaction Direct seeded crops may be more cold tolerant than transplants
Row Covers Provide up to 8 degrees of frost protection Must be managed daily Use 0.5 oz and double if needed Small hoops or racks with slide systems can be used
Managing Row Covers The igloo effect Open covers on sunny days in the morning Cover crops at the end of the day before temps fall again Very cold conditions.maybe two layers of covers?
Winter = low water requirements, crop grows slowly and HT is humid Drip tape is useful Water during middle of the day when a mild(er) night is forecast to reduce crop freeze Ventilate when possible Winter Watering
Other issues Downy mildew -from condensation dripping on leaves. Solution: Use resistant varieties Aphids-rogue the plant or spot treat
Winter Harvest Cut and come again crops Midday harvest on sunny days (4hrs) Cut above growing point every 15-35 days Do not remove more than 40% of leaf area at one time Use harvest to thin direct seeded rows Plan ahead for frozen ground
Recordkeeping Winter production is more expensive Harvests are smaller Keep all records (including labor time) and charge accordingly Not just about more $, also retaining satisfied customer base into next year!
Happy Harvests! Questions? Visit our websites to find out about other programs and events: Livingston, McLean, Woodford Unit - http://web.extension.illinois.edu/lmw/ Henderson, Knox, McDonough, Warren Unit http://web.extension.illinois.edu/hkmw/ Illinois Small Farms - http://web.extension.illinois.edu/smallfarm/