University of Illinois

Transcription

1 DIY SEASON EXTENSION Resources for extending your growing season in hardiness zones 5a-6a Zachary Grant Local Food Systems and Small Farm Educator, University of Illinois Extension, Cook County Unit 6

2 Season Extension 101 In hardiness zones 5a-6a the active outdoor growing season is approximately 160 to 180 days. With basic season extension, cultural techniques like using raised beds and transplants can give a grower a few weeks of extension. However, with the creation of microclimates via season extension structures like cold frames, minitunnels, row covers, and high tunnels, a grower in hardiness 5a-6a can extend the harvest season virtually year-round with the right planning, techniques, and structures. For the beginner, using smaller structures to extend the season a few weeks on both sides of the frost free and first frost dates would be a good place to start. The key is the combination of season extension structures with the appropriate cold hardy crops for the season. This guide will lay out some key concepts, plantings dates to begin with, and structure ideas for a small garden setting. It will take some time to develop your season extension skill set, but the reward will be more vegetables throughout more of the season! Salad greens in a mini-tunnel on 11/25 A mini tunnel with double channel lock base on a wooden raised bed

3 Winter Production Guidelines Plant cold/freeze tolerant crops Can survive whole winter: e.g. Spinach, Red Russian Kale, Asian Greens, Carrots Can survive most of the winter: e.g. Lettuce, Arugula, Beets, Radishes Leafy crops will freeze at night, but when the microclimate warms up in midmorning on sunny days. The crops will have thawed and survived for harvesting. DO NOT HARVEST when leaves are still frozen! Plant crops early enough to allow sufficient growth Between Winter Solstice (Dec. 21 st ) and February 1st growth virtually stops due to day length being less than 10 hours. Banking crop growth in fall for winter harvesting For most salad green crops, plant from early September to the 1 st week of October for harvests in November, December, and early January. Spinach can be planted from late September to mid-october for harvests by the end of December, the end of February, and the beginning of April. Plant crops that allow for multiple harvests 2-3 quality harvests can be expected Cut back to 1-2 above soil for regrowth 1 lb every 6 ft 2 or about ¼ lb per ft 2 for most greens and ½ lb per ft 2 for spinach over 2-3 harvests Crops must be protected by high tunnel, low tunnels, or a combination of both 0-15 F warmer night time temperatures can be achieved with the row covers Up to 23 F warmer temperatures with the high tunnel and inner layers combined Ventilate as much as possible Inner covers no more than 18 above crop (most can tolerate row cover directly on crops) Ventilate inner covers at least 2-3 per week regardless of light levels References: Eliot Coleman- Four Season Harvest and The Winter Harvest Handbook MSU High Tunnels Blog- Adapted from Biernbaum, 2009 Season Extension and Winter Harvest Quick Course

4 *These planting dates are based on planting into larger high tunnels with an additional low tunnel layer inside. However, for smaller structures like the mini-tunnel, these dates could be pushed two weeks later for late winter/early spring, and two weeks early for fall plantings. Using the attached soil temperature guide coupled with a soil thermometer along with these dates will be even more effective in determining when to plant. These charts are meant as a guideline only that can be used to fine tune to local conditions.

5 *These planting dates are based on planting into larger high tunnels with an additional low tunnel layer inside. However, for smaller structures like the mini-tunnel, these dates could be pushed two weeks later for late winter/early spring, and two weeks early for fall plantings. Using the attached soil temperature guide coupled with a soil thermometer along with these dates will be even more effective in determining when to plant. These charts are meant as a guideline only that can be used to fine tune to local conditions.

6 *These planting dates are based on planting into larger high tunnels with an additional low tunnel layer inside. However, for smaller structures like the mini-tunnel, these dates could be pushed two weeks later for late winter/early spring, and two weeks early for fall plantings. Using the attached soil temperature guide coupled with a soil thermometer along with these dates will be even more effective in determining when to plant. These charts are meant as a guideline only that can be used to fine tune to local conditions.

7 Information Sheet for 4 x 8 Small-Scale Mini Tunnel Construction Tools to Have On Hand: Compact Cordless Power Drill or Impact Driver (better for Tek Screws) Cordless Sawzall with multi-purpose blades or other saw capable of cutting both wood and metal ½ Metal Conduit Bender and Handle 5/16 Hex head bit for Tek Screws Bit for wood screws and outdoor deck screws (if using wood for base) Drill bits Tape measure Some sort of marking utensil (sharpie) Wire Snips and/or Needle Nose pliers with wire cutting notch Metal File Materials (Tunnel Base Frame and Structure): ½ X 10 metal EMT conduit (5-7, accounting for practice bending) 2 X4 Lumber (3) 8 pieces premium non-treated pine studs or cedar (could use double or single aluminum wire lock for the base instead of 2x4, in which case using all Tek screws instead of wood screws, would be appropriate for assembling base frame and structure). 1 ¼ Exterior or deck wood screws (<1 box) 2-3 Exterior or deck wood screws (8) 3½ Utility hinges and screws (3) ½ Galvanized pipe strap (3-4 bags of 10) #12 x 2 Tek screws (at least 10 hex head type) #12 x 1½ Tek Screws (at least 24 hex head type) #10 x ½ Tek screws (15-50 hex head type) 3 Metal corner braces (4) Some sort of latch (latching hasp, gate latch, etc.) Handles All purchased at most hardware stores (Lowe s, Menards, Ace, etc.) Materials (Plastic and Attachment): W X 16 L sheet of 6 mil clear UV stable greenhouse film sold in linear ft. in various widths (FarmTek sells it this way, if building more than one, buy a 14 W role by however many tunnels you are making) 32 single channel wire lock base (6) 8 sections (two can also be used for lengthwise (purlin) support 32 wiggle wire (12) 4 sections Polyethylene, wire lock channel, and wiggle wire purchased on-line from Farm Tek or another similar vendor University of Illinois Extension provides equal opportunities in programs and employment

8 Process: - Layout tools and materials on a large flat surface (driveway, patio, or garage floor) - Measure out one 8-2 X4 stud into two 4 sections; using sawzall, make cut so there are two pieces 4 in length. You will now have the two 8 studs and two 4 cut studs to make tunnel base frame. If using channel lock, cut into similar sections and connect using the 3 corner braces and Tek Screws. - Connect studs into a 4 X8 rectangular base frame using butt joints (length pieces upright, squared, and butted perpendicular to width pieces); attach the 3 corner braces to the inside center of the corners of the base frame with 1 ¼ exterior screws using the cordless drill and bit. You can add a couple 2-3 exterior screws through the butt joint from the outside of the frame (with pre-drilled holes) for reinforcement. - Using the pipe bender bend the ½ metal conduit to the specifications in the attached details - Attach the bent conduit hoops to the base frame; in equal spacing; to the inside of the base frame using the ½ galvanized pipe strap, 2 Tek screws (through the strap, conduit, and into wood), and the 1 ¼ exterior wood screws (through the holes in the ends of the pipe strap into wood). If using channel lock, just drill ¾ Tek Screw through channel lock into hoop. Note: the hoops should exert a little outward pressure against the inside of the base frame allowing them to stand alone, and therefore be easier to connect. - Attach 1-2 channel locks down the length of the structure to give lengthwise (purlin) support. - Attach the single channel wire lock base around outside of the wood frame using 1½ Tek screws; trim the wire lock base with sawzall as necessary to fit the frame and file rough edges. If only using channel lock then you would skip this step. - Put the hoop structure on top of a 4 X 8 raised bed (see attached) or a simple raised bed frame (using the same butt joint method from above, but with 2 x10 boards). Make sure butt joints on the tunnel base frame and raised bed frame are connected the same way. -Attach the 3½ or appropriately sized hinges, equally spaced, to the outside of one of the 8 sides of the tunnel base frame and the raised bed. -Install latch between the tunnel base frame and raised bed frame. Install handles to tunnel base frame. - Attach the W X 16 L greenhouse plastic film covering to the hoop frame using wiggle wire over the film and into the channel lock base. Fold and cut the plastic to fit the frame. Let a little plastic drape (1-2 ) past the lock base. It is also helpful to put an extra cut strip of plastic between the wiggle wire and the tunnel plastic to prevent rips when attaching the wiggle wire into the lock base. Cut excess wiggle wire with wire snips. It is also possible to attach a separate piece of plastic to the end with ½ snap clamps.

9 Process Developed by Zachary Grant Local Food Systems/Small Farm Extension Educator University of Illinois Extension Review attached budgets for other examples and ideas for small mini tunnel structures U of I Extension does not endorse any vendor or resource. Those listed are merely examples for educational purposes only. WARNING: The persons assembling this structure are responsible for designing and furnishing all temporary bracing, shoring, and support needed during the assembly process. For safety reasons, those who are not familiar with recognized construction methods and techniques mentioned above must seek the help of a qualified contractor. U of I Extension does not accept responsibility for any injuries or damages affiliated with the construction of these structures nor guarantee the quality of a finished structure based on this process.

10

11 Suggested Reading Blomgren, Ted and Frisch, Tracy High Tunnels: Using Low-Cost Technology to Increase Yields, Improve Quality and Extend the Season. University of Vermont Center for Sustainable Agriculture. 77 p. Bycynski, Lynn (editor) The Hoophouse Handbook: Growing Produce and Flowers in Hoophouses and High Tunnels. Fairplain Publications. 60 p. Coleman, Eliot Four-Season Harvest. Chelsea Green Publishing, Post Mills, VT. 212 p. Coleman, Eliot The New Organic Grower: A Master s Manual of Tools and Techniques for the Home and Market Gardener. 2nd Edition. Chelsea Green Publishing, Lebanon, NH. 270 p. Coleman, Eliot The Winter-Harvest Manual: Farming the Back Side of the Calendar. Four Season Farm. 62 p. Coleman, Eliot The Winter Harvest Handbook: Year-Round Vegetable Production Using Deep-Organic Techniques and Unheated Greenhouses. Chelsea Green Publishing, Post Mills, VT. 247 p. Fortier, Jean-Martin The Market Gardener. New Society Publishers, Gabriola Island, BC, Canada. 223 p. Helpful Websites Eliot Coleman s web site High Tunnel pricing spreadsheets, floating row covers, seeds, etc. (really cool day length calculator) U of I Extension Resources (greenhouse plastic, wiggle wire, etc.) Nolt s Produce Supply (call to receive product catalog, ) U of I Extension does not endorse any one particular vendor or resource. Those listed are merely examples for educational purposes only. University of Illinois U.S. Department of Agriculture University of Illinois Extension provides equal opportunities in programs and employment.