WINTER HARVEST RESEARCH PROJECT

WINTER HARVEST RESEARCH PROJECT College of the Rockies Community Greenhouse Row Cover Experiment Report 2009-2011 The College of the Rockies Community Greenhouse extends their thanks and appreciation to the INVESTMENT AGRICULTURE FOUNDATION OF BRITISH COLUMBIA and COLUMBIA BASIN TRUST for funding the Winter Harvest Research Project.

Winter Harvest Project - Row Cover Experiment Report College of the Rockies Community Greenhouse 2009-2011 Hypothesis #1: There will be no difference in plant growth among three different weights of plant covers used in growing environments in a hoop house over the growing season. This was tested in a uniform environment for all covers. Description of growing environment, growing beds and covers used: Growing Environment: The experiment took place in a hoop house covered with two layers of greenhouse plastic. The hoop house is 60 long and 25 wide and is not heated. It has sliding doors at each end for ventilation. It is located in the town of Creston which is gardening zone 6a. The greenhouse has an east-west orientation and is in an unsheltered area which can be buffeted by wind during inclement weather. Growing Beds: The hoop house contains 18 raised beds measuring 4 x8 x1 deep. Installed in each bed were three 9 gauge galvanized wire rectangular wire hoops. Each hoop started with a wire 8 long which was bent at a right angle at the two foot and 6 foot point forming an open bottomed rectangle 4 wide. Each end was inserted 1 into the ground to form a support 1 tall. Covers: Three weights of floating row covers were used:.5 oz, 1 oz and 1.5 oz. Floating row covers are made of remay fabric. Remay fabric is spun bonded, white, non-woven polyester fabric which allows the passage of water, light and air. Plastic covers were not chosen for this purpose because of its inability to allow ventilation without being opened each day thus requiring quite a bit more labour. Size of covers for each bed were 7 wide and 12 long. Fabric was held to the hoops by clothes pegs. Note that beds with 1.5 oz covers were given 1 oz covers for the main part of the growing season and an extra half ounce was added during the coldest part of the winter to determine if the additional covers made any difference in growth or ability to survive. Costs: #9 galvanized wire was purchased in a hardware store for 14 cents a linear foot. Row covers were purchased from a wholesale garden supplier called The Professional Gardener Co. Ltd. located in Calgary Alberta. All rolls are 7 x 500 and prices do not include shipping or tax. Note these are wholesale prices. -.5 oz cover costs $90.35 per roll - 1 oz cover costs 128.54 per roll - 1.5 oz costs $171.59 per roll Crops Grown: The following 16 cold tolerant vegetables were tested: arugula, beets, carrots, corn salad, Hakurei turnips, Italian dandelion, kale, komatsuna, leeks, lettuce, mizuna, radicchio, radish, scallions, spinach and spring planted Swiss chard.

Planting Groups 0.5 oz cover Bed 1 Leeks, scallions, radish, kale Group 1 Group 2 Group 3 Group 4 Group 5 Bed 4 Bed 10 Komatsuna, Carrots, rouge beet, radicchio lettuce, arugula Bed 7 Italian Dandelion, mizuna, corn salad Bed 13 Hakurei turnips, romaine lettuce, swiss chard, spinach 1 oz cover Bed 2 Leeks, scallions, radish, kale Bed 5 Komatsuna, beet, radicchio Bed 8 Italian dandelion, mizuna, corn salad Bed 11 Carrots, rouge lettuce, arugula Bed 14 Hakurei turnips, romaine lettuce, swiss chard, spinach 1.5 oz cover Bed 3 Leeks, scallions radish kale Bed 6 Komatsuna, beet, radicchio Bed 9 Italian dandelion, mizuna, corn salad Bed 12 Carrots, rouge lettuce, arugula Bed 15 Hakurei turnips, romaine lettuce, swiss chard, spinach Covering Procedures: Bed 1,4,7,10 & 13 0.5 oz Covers Add 0.5 oz cover Nov 1 Bed 2,5,8,11 & 14 1 oz Covers Bed 3,6,9,12 7 15 1.5 oz covers Add 1 oz cover Nov 1 Nov 1 Add additional 0.5 oz cover Remove 0.5 oz cover (leave in place 1 oz cover) Dec 7 Feb 4 Remove all covers March 22 March 22 March 22 Note 1: November 1 was chosen because that was the time temperatures consistently dipped to below zero C overnight. Note2: December 7 was chosen because that was the time temperatures consistently dipped to below -10 C overnight. Note 3: February 4 was chosen because that was the time temperatures consistently rose above -10 C overnight and also mould was appearing on some plants in the group with heavier cloth which may have been due to less ventilation.

Results: Some crops did not make it through the winter under any type of cover. Radish, Hakurei turnips, spring planted Swiss chard were among the crops that performed well in the fall season and were harvested until the beginning of December when temperatures consistently fell to below -10 C. Some crops performed equally well with any weight of cover: beets, carrots, corn salad, Italian dandelion, kale, leeks, lettuce, scallions, and spinach. Mizuna performed well with 1 and 1.5 oz covers and the crop with 0.5oz cover was lost. Performance was determined by a visual inspection of the crops on Feb. 4, 2010. We looked at plant size, vigor and general health. It was found cover weight did make a difference in performance with the following crops: arugula, komatsuna, and radicchio. For example, radicchio and komatsuna survived under all three weights but under the 0.5 oz cover received more frost damage, were smaller and had less vigor while under the 1.5 oz cover were larger and healthier looking. Arugula did not survive under a 0.5 oz cover but did well under 1 and 1.5 oz. Spring Survival Rates by cover: 0.5 ounce cover 1 ounce cover 1.5 oz cover Arugula Poor performance and Good Good death Beets Good Good Good Carrots Good Good Good Corn Salad Good Good Good Hakurei Turnips Did not survive winter Did not survive winter Did not survive winter Italian Dandelion Good Good Good with some mould Kale Good Good Good Komatsuna Poor Good Best Leeks Good Good Good Lettuce Good Good Good Mizuna Unable to assess because Good Good of fall insect damage Radicchio Good Better Best, some mould Radish Did not survive winter Did not survive winter Did not survive winter Scallions Good Unable to assess due to Good insect damage Spinach Good Good Good Spring planted Swiss Chard Did not survive winter Did not survive winter Did not survive winter

Conclusions and Recommendations: It was found that cover weights did not make a difference for beets, carrots, corn salad, Italian dandelion, kale, leeks, lettuce, scallion and spinach. Mizuna performed well with both 1 oz and 1.5 oz but data was unavailable on 0.5 oz because of insect damage. Komatsuna and Radicchio performed best with a 1.5 oz cover. Arugula did not perform well with a 0.5 oz cover but did well with both a 1 oz and a 1.5 oz cover. Hakurei turnips, radishes and spring planted Swiss chard did not survive the winter under any type of cover. These conclusions are valid for the weather conditions experienced this winter. It was also found that the vegetables that did not survive the winter were excellent producing fall crops. It is recommended that the 1 oz covers be used in the future for growing winter vegetables for the following crops: arugula, beets, carrots, corn salad, Italian dandelion, kale, leeks, lettuce, mizuna, scallion and spinach. It is recommended that a 1.5 oz cover be used when temperatures are below -10 C for the following crops: komatsuna and radicchio. It is recommended that the following crops be grown as fall producers only: radish, Hakurei turnips, spring planted Swiss chard. Hypothesis #2: There will be no difference in plant growth between two different types of coverings in two cold frames. Description and cost of growing environment beds and covers used: 1) Cold Frame #1 (CF#1) This cold frame was built on top of gravel using 2 x 12 lumber for the frame and 2 x 2 lumber for the top ridges to hold the lid which is made out of tempered glass. The dimensions are 57 x 61. It was filled with top soil and top dressed with composted manure. Gaia Green fertilizer and Glacial Rock Dust were also worked into the soil. Location: COTR Community Greenhouse, Creston, BC, Materials used: 2 x 12 & 2 x 2 lumber Hinges & wood screws Tempered glass top (recycled shower doors) Total cost: 50.00 (approx.) 2) Cold Frame #2 (CF #2) 3) This cold frame was built on top of an existing garden bed in the COTR Community Greenhouse Garden. There was not protection from wind other than the lid. It was built using 2 x 12 lumber for the frame and 2 x 2 lumber to frame the polycarbonate lids and the dimensions are 30 x 94. The lids were attached using hinges and were propped open on days when it was above 0 degrees. The garden soil was enhanced with composted manure, Gaia Green fertilizer and Glacial Rock Dust. Location: COTR Community Greenhouse, Creston, BC Materials used: 2 x 12 & 2 x 2 lumber Hinges & wood screws Sheet of 4.5 ml polycarbonate (recycled) Total cost: 50.00 (If it had been built using new polycarbonate the cost would have been a total of 100.00) Locations: - Bed 1 was placed on the south side of a large unheated greenhouse and was protected from north winds. - Bed 2 was placed in the middle of a large vegetable garden with no protection other than the lid. Both beds had their lower edges facing south.

Covers Used Cold Frame #1 Cold Frame #2 Covering material Tempered Glass Shower Doors Polycarbonate 4.5 ml Plants Used Both cold frames were planted with Bloomsdale Spinach and Ralsielane lettuce Procedures Both frames were seeded in mid August and cold frame lids were added mid-october. Lids were propped open during the day when the weather was not windy and temperature was above 0 C and closed at night. Gaia Green All Purpose natural fertilizer and home-made compost was added to garden soil in beds. Harvest could not be done in the winter due to deep snow and the lids being frozen in place. Results Cold Frame #1 Cold Frame #2 Covering material Tempered Glass Shower Doors Polycarbonate 4.5 ml Bloomsdale Spinach Ralsielane lettuce Good performance in fall, did not die back in winter, excellent performance in spring. Plants grew large and hardy in spring. Good performance in fall, 90% of the plants died over the winter with the few surviving plants harvested in spring Good performance in fall, did not die back in winter, excellent performance in spring. Plants grew large and hardy in spring. Good performance in fall, 0% die back in winter with spring plants having excellent taste and vigor Conclusions and Recommendations: - A cold frame with a tempered glass or polycarbonate lid is an ideal place to grow a fall through spring crop of Bloomsdale spinach. It may not be possible to harvest in the winter when snow is deep and the lid may be frozen in place. Plants will be larger and more robust in the spring than in the fall. - A cold frame with a polycarbonate lid is a better environment for Ralsielane lettuce for fall through spring production. A cold frame with a tempered glass lid is an excellent place to grow a fall crop of Ralsielane lettuce but may not keep the lettuce alive through the winter. - A cold frame covered with a polycarbonate lid should be used for maximum winter protection when growing spinach and lettuce.