Passive Solar Greenhouse/Coldframe Planning: Crop Mix, Location (Rotation) and Scheduling John Biernbaum and Adam Montri, Michigan State University The following information and examples can be used to schedule planting for passive solar greenhouse (PSGH) vegetables, herbs or flowers. Examples are based on personal experience and research at home and at the MSU-Student Organic Farm, as well as observing other farmers. A good description of how one commercial grower uses a similar hand drawn template is provided on pages 36 to 40 of the book Walking to Spring: Using high tunnels to grow produce 52 weeks a year. (Authors Paul and Alison Wiediger of Au Naturel Farm). It is important to note that they are located in Kentucky so not all the methods recommended there will work in more northern climates. Crop Mix (What to Plant? and How Much to Plant?) Prior to scheduling, a crop mix plan is developed based on the market being served. The crop mix will change over the season from cool season to warm season and back to cool season crops. The quantities of each crop planted are primarily influenced by the crop productivity per unit area (data available from catalogs), the market being served and the demand and profitability of the items produced. Crop Mix Example: What crops do you intend to grow and what percent of the space do you plan to use for each? These decisions will also depend on what you want to market and when you want to market it, but crop mix is a first step. What you will grow for personal home use vs a farm stand vs CSA vs restaurant sales will be different. The crop mix allows the calculation of how much of the greenhouse space will be planted to each crop (estimates of number of square feet or beds). Example Fall Crop Selection and Mix - Lets start with a crop mix of four categories of crops for winter harvest. 25% Root crops: carrots, beets, turnips, radishes, green onions 25% Head crops: lettuce (multiple types), Chinese (napa) cabbage, pac choi, tatsoi 25% Leafy greens: spinach, chard, kale, collards, komatsuna 25% Baby leaf salad greens (BLSG): lettuce (multiple types), spinach, mizuna, kale, beets, chard, Tokyo Bekana napa cabbage, arugula, tatsoi, pac choi, claytonia, mache, etc Crop Location and Rotations (Where to Plant It?) Prior to scheduling, a crop location and rotation, plan are developed based on the crop mix. Crop location in the greenhouse can be influenced by several factors (light, convenience, etc), but a key one is the need for a rotation. One of the reasons for having a crop mix is that it is not biologically sustainable to grow the same crop in the same spot over time due to the likely development of diseases or insects specific to the crop. Similar types or related species of plants can be put into groups that require similar amounts of growing area. John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 1
Example Location and Rotation: For the first year of planting, placement is not dependent on the previous crop. But in later years, the categories need to change location. The basic idea of a rotation is to not plant the same crop or closely related crops in the same place over time. For example, tomatoes, peppers and eggplants are closely related; cabbage, broccoli and cauliflower are closely related. Winter 1 Winter 2 Winter 3 Winter 4 Bed 1: root BLSG leaf head Bed 2: head root BLSG leaf Bed 3: leaf head root BLSG Bed 4: BLSG leaf head root Crop Scheduling and Succession Planting (When to Plant It?) If your goal is to maximize production and income, your goal is to keep the greenhouse space as full as possible over the season. Scheduling is developed for each individual crop, and then for all the crops in relation to each other. Once greenhouse space is scheduled, say for lettuce, a schedule to sow and prepare transplants is also developed. Lower light and temperatures in the fall slow down growth significantly so seasonal adjustments in crop time must be made. Succession or regular planting is used to insure that crops can be harvested and space is full on a constant basis. Example Scheduling: Learning about crop scheduling and rotations can be done by starting simple and then getting more complicated. Let's start with an example for a simple backyard greenhouse, 16' x 16'. Each quadrant of the greenhouse could be a 3.5' x 3.5' bed; for the example below, 25% is the amount of space used for each bed. Location Crop Type Aug wk 1 Aug wk 2 Aug wk 3 Aug wk 4 Sept wk 1 Sept wk 2 Sept wk 3 Bed 1: Roots: carrots green onion turnips radishes Bed 2: Bed 3: Heads: Leafy: Bed 4: BLSG: seed transplants seed transplants napa, pac, lettuce chard, kale komat seed spinach seeding through September Sept wk 4 John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 2
Example of PSGH Crop Scheduling at the Michigan State University Student Organic Farm Crop Warm Season (1) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec basil TS P H H H H R cucumber TS P H H H R egg plant TS P H H H R pepper TS P H H H R summer squash TS P H H H R tomato TS P H H H R Cooking Greens (2) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec arugula H H/DS H H DS H H H beet H H/DS H H DS H H H chard H/TS H/TS P H H TS TS P H H H collard H/TS H/TS P H H TS TS P H H H kale H/TS H/TS P H H TS TS P H H H Komatsuna H/TS H/TS P H H TS TS P H H H mustard H/TS H/TS P H H TS TS P H H H spinach H H/DS H/DS H H DS H H H turnip H H/DS H/DS H H DS H H H Heading Greens (3) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec romain lettuce H/TS TS/P P H H TS P P/H H H oak leaf lettuce H/TS TS/P P H H TS P P/H H H soft head lettuce H/TS TS/P P H H TS P P/H H H Chinese cabbage H/TS TS/P P H H TS P P H H H mei quing choi H/TS TS/P P H H TS P P/H H H pac choi H/TS TS/P P H H TS P P/H H H Root Crops (4) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec beet H DS H H carrot H/DS DS H H DS H H hakurei turnip H/DS DS H H DS DS H H potato DS H H radish H/DS DS DS/H H H DS DS H H Baby Leaf Salad (5) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec arugula (f) H DS DS H H DS DS/H H H beet (s) H DS DS H H DS DS/H H H chard (s) H DS DS H H DS DS/H H H John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 3
CC Tokyo Bekana (f) H DS DS H H DS DS/H H H kale Red Russian (f) H DS DS H H DS DS/H H H lettuce red (s) H DS DS H H DS DS/H H H lettuce green (s) H DS DS H H DS DS/H H H mizuna (f) H DS DS H H DS DS/H H H pac choi (f) H DS DS H H DS DS/H H H spinach (s) H DS DS H H DS DS/H H H tatsoi (f) H DS DS H H DS DS/H H H Cool Season Herbs Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec cilantro H H H/DS H/DS H/DS H/DS H/DS H/DS H/DS H/DS H H parsley H H H TS P H H H H Table Information (1) harvest can continue into Sep Oct if space allows (2) - if fall plants are still growing and producing, do not replant (3) - late February and early September for planting (4) May be more efficient from field or storage; carrots must be sown by first week of August (5) faster (f) & slower (s) crops TS=sow transplant seed in heated greenhouse DS=direct seed in beds P= plant transplants into beds H= harvest R= remove plants John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 4
Vegetable Transplant Spacing Assumptions and Guidelines for the MSU SOF CSA Spacing Code Plants per bed ** square inches per plant square feet per plant spacing Rows per bed Plants per row Beds per 128 cell plug tray Beds per CSA**** distribution 1 120 24 0.17 5" x 5" 4 30 1 1 2 60 48 0.33 7" x 7" 5 12 2 1 3 30 96 0.67 10" x 10" 3 10 4 2 4 20 144 1.00 12" x 12" 2 10 6 3 5 16 180 1.25 13.5"x13.5" 2 8 7 4 6 12 240 1.67 15" x 15" 2 6 10 5 7 4 720 5.00 2.5' x 2' 1 4 NA NA 8 2 1440 10.00 2.5' x 4' 1 2 NA NA 9 trellis 120 to 360 0.8 to 2.5 2.5' x 4" to 12" 1 24 to 8 NA NA **Our bed size = (30"x96") = 2888 square inches or 20 square feet **** Our CSA membership is approximately 55 and we plan for some extra These are not intended as ideal spacings for all situations. They should be useful for starting and comparing. Code Crops 1 scallions (multiples) 2 kohlrabi, mei qing choi 3 Chinese cabbage, komatsuna, lettuce, pac choi, parsley, radichio, tatsoi 4 celery, bulb fennel, basil, potatoes (depends on variety) 5 chard, collards, kale, potatoes (depends on variety) 6 broccoli, califlower (not usually done in the PSGH) 7 eggplant, peppers; (field spacing is more like code 5 or 6). 8 tomatoes, summer squash and large plants 9 trellis: peas (4" in row), pole beans (6" in row), or cucumbers (12" in row). John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 5
Fall Seed Order for Example MSU Student Organic Farm Fall Planting Plan Crop Cultivar # in JSS* Pg in JSS Size (Wt. or Seed #) $ Estimated seeds or plants/100 ft2 Baby Salad*** Various Various 46-47 1/4 lb total 20,000 seeds Beet Chioggia 130(G) 9 1 oz (~2200 seeds) 5.50 480 (3" in row, 10" between rows) Beet Golden 128(G) 9 1 oz (~2200 seeds) 11.50 480 (3" in row, 10" between rows) Carrots Napoli 209 15 25,000 18.00 14,400 seeds Carrots Sugar Snax 2322 15 25,000 15.75 14,400 seeds Chinese Cabbage Rubicon 2246 13 5,000 seeds 13.45 150 Choi Black Summer 2460 34 1 oz 5.40 150 Choi Joi 507 34 5,000 seeds 11.40 150 Choi Mei Quin 509 34 5,000 seeds 11.40 150 Cilantro Santo 919 99 1/4 lb 5.40 Collards Flash 2116 38 1/2 oz (3,500 sds) 8.95 80 Kale Red Russian 363(G) 37 1 oz (~350 sds) 5.50 80 Kale Toscano 2123 37 1 oz (~350 sds) 9.00 80 Lettuce Aruba-Red Oakleaf 2362 42 1/2 oz (~12,000 sds) 7.80 150 Lettuce Ermosa-Green/Bibb 437 44 1/2 oz (~12,000 sds) 19.00 150 Lettuce Winter Density-Rom 442N 42 1/2 oz (~12,000 sds) 11.20 150 Parsley Italian Dark Green 529 106 1 oz (~12,500 seeds) 5.15 150 Raddichio Indigo 2245 19 500 seeds 13.00 150+ Radish D'avignon 67 620 1/4 Lb (~10,000 sds) 14.95 8400 (35 seeds/ft, 4 1/2" btwn rows) Radish Easter Egg 67 617 1/4 Lb (~10,000 sds) 5.95 8400 (35 seeds/ft, 4 1/2" btwn rows) Scallion** Dp Purple, Hdy White 491, 502 55 * * * Spinach Space 664 70 10,000 $6.40 150 Swiss Chard Bright Lights 730D 76 1,000 seeds 5.20 80 Tatsoi N/A 515 33 1 oz 4.60 150 Turnip Hakurei 706 84 1 oz (~10,000 seeds) 0.50 720 (2" in row, 10" between row) Turnip Scarlett Queen 2374 84 1 oz (~10,000 seeds) 15.30 720 (2" in row, 10" between row) *JSS=Johnny's Selected Seeds **Scallions should be direct seeded at very close spacings. Another option that we have not pursued but that has been successful for other growers is to seed 8-10 scallions per cell in a tray, then transplant out the entire cell. When the scallions are ready to harvest they are already in bunches and they can be pulled, banded, and ready to go. ***Baby leaf salad greens can be a combination of most any baby greens. Our mix usually includes lettuces, red giant mustard, kale, bull's blood beet greens, and mizuna. In addition you could include swiss chard, arugula, tatsoi, spinach, mibuna, or other greens. In the late planting we often include 'Tokyo Bekana' chinese cabbage because it is more cold tolerant than the lettuces. Also, lettuces, beet greens, chard, and spinach should be seeded 1 week prior to asian greens, arugula, mustard, etc. because they are slower growing. This allows all greens and lettuces to be a similar size when harvested. John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 6
Example Fall Planting Schedule for MSU Student Organic Farm in East Lansing, MI (Zone 5) Crop Cultivar Direct Seed (DS) or Transplant (TP) Actual Date Seeded (for record keeping) Scheduled Transplant Date Actual Date Transplanted (for record keeping) Scheduled Seed Date Annual Week Annual Week Baby Salad Various- fast DS 9/4 and 10/8 36 & 41 n/a Baby Salad Various- slow DS 8/27 and 10/1 35, & 40 n/a Beet Chioggia DS 13-Aug 33 n/a n/a Beet Golden DS 13-Aug 33 n/a n/a Carrot Napoli DS 1-Aug 31 n/a n/a Carrot Sugar Snax DS 1-Aug 31 n/a n/a Chinese Cabbage Rubicon TP 6-Aug 32 4-Sep 36 Choi Black Summer TP 6-Aug 32 4-Sep 36 Choi Joi TP 6-Aug 32 4-Sep 36 Choi Mei Quin TP 6-Aug 32 4-Sep 36 Cilantro Santo DS 4-Sep 36 n/a n/a Collards Flash TP 24-Jul 30 20-Aug 34 Kale Red Russian TP 24-Jul 30 20-Aug 34 Kale Toscano TP 24-Jul 30 20-Aug 34 Kale Winterbor TP 24-Jul 30 20-Aug 34 Lettuce Aruba-Red Oakleaf TP 13-Aug 33 18-Sep 38 Lettuce Ermosa-Green/Bibb TP 13-Aug 33 18-Sep 38 Lettuce Winter Density-Rom TP 13-Aug 33 18-Sep 38 Parsley Italian Dark Green TP 6-Aug 32 4-Sep 36 Raddichio Indigo TP 24-Jul 30 20-Aug 34 Radish D'avignon DS 4-Sept and 18-Sept 36 and 38 n/a n/a Radish Easter Egg DS 4-Sept and 18-Sept 36 and 38 n/a n/a Scallion Dp Purple, Hdy White DS/TP 6-Aug 32 n/a n/a Spinach Space DS/TP 20-Aug 34 18-Sep 38 Swiss Chard Bright Lights TP 24-Jul 30 20-Aug 34 Tatsoi N/A TP 6-Aug 32 4-Sep 36 Turnip Hakurei DS 13-Aug and 4-Sep 33 and 36 n/a n/a Turnip Scarlett Queen DS 13-Aug and 4-Sep 33 and 36 n/a n/a Prepared by Adam Montri John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 7
Example Spring Planting Plan for the MSU Student Organic Farm in East Lansing, MI (Zone 5) Direct Seed (DS) or Transplant (TP) Actual Seed Date (For Record Keeping) Scheduled Transplant Date*** Actual Date Transplanted (For Record Keeping) Scheduled Seed Annual Annual Crop Cultivar Date*** Week Week Baby Salad* Various-Slow DS 1-Feb 5 - - - Various-Fast DS 8-Feb 6 - - - Beets Golden DS 1-Feb 5 - - - Chioggia DS 1-Feb 5 - - - Detroit Dark Red DS 1-Feb 5 - - - Carrots Sugarsnax DS 1-Feb 5 - - - Napoli DS 1-Feb 5 - - - Chard Bright Lights TP 14-Jan 3 11-Feb 7 Chinese Cabbage Rubicon TP 14-Jan 3 11-Feb 7 Chois Mei Quin TP 14-Jan 3 11-Feb 7 Joi TP 14-Jan 3 11-Feb 7 Cilantro Santo DS 1-Feb 5 - - - Collards Flash TP 14-Jan 3 11-Feb 7 Cucumber Diva TP 27-Mar 13 1-May 18 Eggplant Orient Express TP 1-Mar 9 1-May 18 Nadia TP 1-Mar 9 1-May 18 Kale Red Russian TP 14-Jan 3 11-Feb 7 Toscano TP 14-Jan 3 11-Feb 7 Winterbor TP 14-Jan 3 11-Feb 7 Lettuces** Aruba TP 14-Jan 3 11-Feb 7 Ermosa TP 14-Jan 3 11-Feb 7 Winter Density TP 14-Jan 3 11-Feb 7 Lisianthus Champagne Ser. TP 17-Jan 3 1-May 18 Melon Savor TP 27-Mar 9 1-May 18 Sweet Granite TP 27-Mar 9 1-May 18 Onions (Sweet) Ailsa Craig TP 15-Jan 3 15-Mar 10 Pepper Ace TP 21-Feb 8 15-Apr 16 Carmen TP 21-Feb 8 15-Apr 16 Raddichio Indigo TP 14-Jan 3 11-Feb 7 Radish Easter Egg DS 1-Feb 5 - - - D'avignon DS 1-Feb 5 - - - John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 8
Scallions Deep Purple DS 1-Feb 5 - - - Hardy White DS 1-Feb 5 - - - Snapdragons Rocket Mix TP 15-Jan 3 24-Mar 13 Spinach Space DS/TP 14-Jan 3 11-Feb 7 Statice Sunset Mix TP 21-Feb 8 8-May 19 Pacific Mix TP 21-Feb 8 8-May 19 Summer Squash Zephyr TP 13-Mar 11 15-Apr 16 Sunflower Pro Cut Series TP 4-Feb 6 15-Mar 11 Tatsoi - TP 14-Jan 3 11-Feb 7 Tomato Taxi TP 21-Feb 8 15-Apr 16 Celebrity TP 21-Feb 8 15-Apr 16 Big Beef TP 21-Feb 8 15-Apr 16 Red Sun TP 21-Feb 8 15-Apr 16 Turnips Hakurei DS 1-Feb 5 - - - Scarlett Queen DS 1-Feb 5 - - - Zucchini Sultan TP 13-Mar 11 15-Apr 16 *Baby Salad can be planted again in late March for April and May harvests **Heading crops, including lettuce, can be planted again in early March and early April with space left every 18 inches down the center of the rows to plant tomatoes into on April 15. The lettuce can then be harvested before the tomatoes grow large enough to need that space. ***Seeding and transplanting dates for the U.P. would likely be 2-3 weeks later. John Biernbaum and Adma Montri, MSU Horticulture and Student Organic Farm, Scheduling Information page 9