Fall & Winter Veggie workshop, July 12, Instructor: Chris Konieczka, Clackamas Community College. A Harvest For All Seasons

Transcription

1 A Harvest For All Seasons

2 A Harvest For All Seasons Fall and Winter Vegetable Production Four Keys To Success

3 The Four Keys Use of cold tolerant crops Timely plantings Use of multiple harvest crops Protection of the crop

4 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.

5 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.

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7 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

8 What to Plant? Cold tolerant crops Late fall, winter, or overwintered crops? Balance hardiness and marketability Mostly extending the harvest season Transplants vs. direct seeded crops

9 What to Plant? Greens lettuces, spinach, Asian greens, arugula, kale, chard, corn salad (mache) Roots carrots, beets, turnips, parsnips, radishes Alliums leeks, green onions Consult seed catalogs, neighbors, extension, etc. for locally adapted varieties

10 What to Plant? 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

11 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

12 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

13 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 Keep records on days to maturity for winter crops

14 When to Plant? Average Frost Free Period for north coast May 15 Oct. 1 (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

15 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 Heat? Direct seeded crops may be more cold tolerant than transplants

16 Row Covers Provide up to 8 degrees of frost protection Must be managed daily Removed at least 2-3 times per week Use 0.5oz. and double if needed Small hoops or racks with slide systems can be used

17 Low Tunnels In-field season extension Low cost Require management of temp and humidity Consider plastic for rainy climate Air circulation can be difficult

18 Winter Watering 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 whenever possible

19 Other issues Downy mildew -from condensation dripping on leaves. Solution: Use resistant varieties Aphids-rogue the plant or spot treat

20 Air Flow Even temperature Reduced disease Roll-up sides Vents Fans

21 Air Flow

22 Winter Harvest Cut and come again crops Cut above growing point every days Do not remove more than 40% of leaf area at one time Use harvest to thin direct seeded rows

23 Winter Harvest - Nitrates Most danger in late fall Spinach, leafy greens, bok choy, endive Afternoon harvest on sunny days Use organic manure sources of fertility = slow release Choose Ammonium fertilizers Remove covers early

24 Recordkeeping Winter production is more expensive Harvests are smaller Keep all records (including labor) and charge accordingly Not just about more $, also retaining satisfied customer base into next year!

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26 Happy Harvests! Questions?