Why rotate crops?Maximize productivityOptimize the health and fertility of the land,Reduce diseases and pests,Increase opportunities to plant cover crops,Meet Organic Certification requirements,Make the planning work easier on the brain.
Our StoryWe garden 3.5 acres ofland, producing vegetablesand berries for 100 people allyear at Twin Oaks Community.We have a mixed gardensystem:• 60 permanent raised beds, each 4 × 90 (1.2 × 27.4 m),• 10 plots of 9,000–10,600 ft2 (836–985 m2), in three areas of “flat” garden.
Before planning a rotationDecide how your farming will support youDecide what you want to growFigure out how much of what you needHave an idea of when to plant each crop.Planning is definitely circular, but you need to start somewhere!
Permanent raised beds Photo Kathryn Simmons• We cultivate the 60 beds manually and with a walk-behind tiller.• We don’t use a permanent rotation plan - we like the extra flexibility of our ad hoc method.• We use the space very intensively and get high yields.• We plant a new crop as soon as we clear an old one.• Some beds will get two or three crops in one season.• If we have a 4-week gap in the summer, we grow buckwheat; if 6 weeks, we add soy to the buckwheat.
Photo Kathryn Simmons We use the beds for:• Crops we grow in small quantities (celery, okra),• Very short-term crops (like lettuce),• Things we need to cosset (eggplant, because of the flea beetles, or early muskmelons),• Experimental crops we want to keep a close eye on• Things that wouldn’t fit anywhere else.• Over-wintering crops we keep long after the rest of the gardens are in winter cover crops (kale, collards and leeks) - the raised beds are more accessible for winter harvesting.• Very early crops such as peas - the beds can be cultivated earlier than the flat gardens.
Raised Bed Planning• Twice a year: – in the winter for the crops planted before the end of July – in mid-June for the crops for the second half of the year.• This two-part planning allows us the flexibility to respond to unexpected situations: – crop failures, – sudden needs for more of something sooner than we’d planned, – something taking longer than expected to reach maturity, etc.• A vital tool for this is our Colored Spots Plan, an outline map of the raised beds that shows the history of the crops planted in each one.
The ColoredSpots Planhelps us seeat a glancewhich cropshavebeen plantedwhere inrecent years.2002-2009shown here.
Vegetable SudokuWe make a chart of how many beds of which cropswe want, divided by family, along with the plantingdate and final harvest date. The amounts we hope to plant come from the previous planning stages. We try to have two or three years’ gap before the same crop family returns to a bed. We shoehorn in more crops during the season than we otherwise could. Sometimes this process leads to the sad realization that everything we want isn’t possible
Photo Kathryn Simmons Sometimes it leads to a more creative solution, such as trying five rows of carrots in a bed rather than four, or planting lettuce as we remove spinach, working along the bed. We always have to do a bit of backtracking and some fudging of the rotation to a less-than- perfect match, but we do end up with a plan that uses the beds fully. It might be a more efficient use of time to design a fixed rotation, but this flexible approach is a more efficient use of land.
SPRING RAISED BED PLANNING CHART – Up to 4 August 2013 Areas/Garden/Planning/Spring Raised Bed Planning Chart.doc Pam 14 January 2013CROP # of When Needed When Finished Beds Available Decision (And when available) BedsKale: Spr 13 Mar mid June 3Collards: Spring 1 13 Mar mid JuneSenposai: spr 1 15 Mar late May-JunTurnips* ½ 6 Mar mid JuneKohlrabi* w/radish ½ 13 Mar mid June¼Cabbage: 1 10 Mar late May-JunspringFall sdlgs 1 21 + 28 Jun early Augfoll by kale 1 28 Jun + 5Jul mid Aug? 1 Poss 12 Jul Late Aug?Chinese 1/3 10 Jul winter 10 Julcabbage* 0 winterTokyo 17 JulBekana* 1/3 4 Aug winterYukina Savoy* 1/3 or winterWinter moreRadish*Cabbage, 1 14 July OverwinteroverwinterSenposai 2 17 Jul OverwinterKohlrabi 1 23 Jul-3 Aug winterCollards: fall 0 27 Jul overwinterKale: fall 2 4 Aug overwinterSpinach 4 10/21 Feb mid May(Jun)Beets 3 15 Mar mid-Jul 3 1 Aug NovChard 1 29 Apr winter
The Main GardensThe main part of our garden is in three patches, withrows 180, 200, or 265 feet (55, 61, or 81 meters) long.• Initial cultivation is with a tractor and disks. – We also have a manure spreader for compost, a seed drill for cover crops and a potato digger.• For some crops we create temporary raised beds,• Other crops are grown in rows “on the flat.”• Here we use our ten-year rotation, growing – major crops – most of our succession crops of beans, squash and cucumbers.• It’s a ten-year plan that rotates crops - it isn’t ten years between corn plantings or potato plantings.
Steps to creating a permanent rotation1. Figure out how much area needed for each major crop (the ones needing the largest amount of space).2. Measure and map the land available3. Divide into equal plots4. Group compatible crops together to fill each plot5. Determine a good sequence6. Include cover crops7. Include no-till crops8. Try it for one year, then make improvements
Step 1. Major cropsFigure out how much area we need for each of our major crops (the ones needing the largest amount of space).In terms of space occupied, ourbiggest crop is corn. Infact, sweet corn is such a spacehog that we use three of our tenplots for it!Photo Kathryn Simmons
Space needed for major crops• Sweet corn: 6 or 7 plantings of about 3,500 ft2 (322 m2) each• Spring planted potatoes: about 7,000–9,000 ft2 (644–828 m2)• Summer planted potatoes: about 7,000–9,000 ft2 (644–828 m2)• Spring broccoli & cabbage: 4,000 ft2 (368 m2)• Fall broccoli & cabbage: 7,000 ft2 (644 m2)• Winter squash: about 8,200 ft2 (736 m2)• Watermelon: about 9,000 ft2 (828 m2)• Sweet potatoes: about 4,300 ft2 (396 m2)• Tomatoes: 4,000 ft2 (368 m2)• Peppers: 2,200 ft2 (202 m2)• Garlic: about 3,600–4,000 ft2 (332–368 m2)• Fall carrots: about 3,600–4,000 ft2 (332–368 m2)
Step 2.Measureand Map: East Garden227’ x 265’(Includesasparagus in halfof one plot)Map showsplots of 9,275-10,600 ft2
Step 2.Measure and Map:West Garden andCentral GardenWest Garden 180’-65’ x 243’Central Garden 200’ x 50’, plus 25’ x 60’ “dogleg”Maps show plots of9,000-10,000 ft2
Step 3. Divide into Equal PlotsIn our gardens, the 7,000–9,000 ft2 (644–828 m2) crops (spring planted potatoes, summer planted potatoes, fall broccoli & cabbage, winter squash, watermelon) will naturally each fill one plot in our rotation, so that was a good size to aim for in setting plot size.
Step 4. Group other crops together to use about the same area: two or three corn • Left to right: Broccoli under rowcover, garlic, strawberries. plantings together in one Photo Kathryn Simmons plot (3,500 ft2 (322 m2) each) spring broccoli together with overwintered garlic (4,000 ft2 (368 m2) + 3,600–4,000 ft2 (332–368 m2 )) tomatoes together with peppers 4,000 ft2 (368 m2) + 2,200 ft2 (202 m2)
Be Ready for SurprisesWe had an open mind about how long a rotationwe would have, but when our major crops fellinto 9 clusters and our area into 10 plots, itsuggested a 10-year rotation, with one plot leftover for year-round cover crops (green fallow).Photo Kathryn SimmonsWinter rye,hairy vetch andcrimson clover
A visual planning methodEliot Coleman’s New Organic Grower was our inspiration in creating a multi-year rotation for the main part of our garden.We initially wrote each major crop on a piece ofgraph paper cut to represent the relative areaneeded. You can use computer programsinstead, even a simple spreadsheet program.See Daniel Parson, Planning the Planting of Cover Crops and Cash Crops, SSAWG 2012 www.slideshare.net/parsonproduce/southern-sawg
Step 5. Start to determine a good sequenceTo help get a crop sequence figured out, we looked at the cropfamilies of our major crops. We have three major plantings of nightshades (Solanaceae): two of potatoes and one of tomatoes and peppers together. Two (spring and fall) of brassicas, Six or seven sowings of corn clustered into three plots, Two of cucurbits (winter squash and watermelons), One of alliums (garlic), One of Umbelliferae (carrots) One of Ipomoea (sweet potatoes).
Give the Family Members Space! Using our modification of Eliot’s method, we put the graph paper pieces in a circle, like a clock face with ten “hours,” and set about imagining a good sequence. Crop rotations are a cycle, and a circular design makes more intuitive sense to us, than a linear format. We started by spreading the three corn plots three or four years apart, and the three nightshade plantings likewise. We kept the winter squash three years after the watermelon.Butternut Squash. Photo Kathryn Simmons
What Not to Worry About.Crops like onions, lettuce, or beets Some crops, like beans andgrow in our permanent raised cucumbers, we plant several times a year, and never a lot at once. We fitbeds, and are not relevant to the those crops in later, according torotation of our major crops. where space is available.Freckles Lettuce, Photo Kathryn Simmons General Lee Cucumber, Photo Kathryn Simmons
Deciding the sequence• Folklore says some crops do better following certain other crops, but has it been tested?• Potatoes are said to do well after corn, so we put our spring potatoes after the previous year’s late corn and our summer potatoes after the previous middle corn planting. This started our sequence.
Step 6, Including cover crops, part AOne of our aims in devising our rotation was to improve our use of winter cover crops.A. For early spring food crops, a preceding cover crop of oats (maybe with soybeans) is ideal, as it winter-kills and is easy to incorporate. o Oats need to be sown at our farm in August or early September (by 9/17), so they need to follow an early finishing crop, such as spring brassicas, spring potatoes or early corn.
Step 6, Including cover crops, part B B. We wanted to add more legumes to our mixes. o To get best value from crimson clover, for example, we need to wait until it flowers — mid-April at the very earliest — before turning it under. o So after crimson clover it’s best if the food crop we plant goes in after the end of April, such as later corn plantings, winter squash, transplanted watermelon, tomatoes, sweet potatoes or June-planted potatoes. o Another factor is that crimson clover is best sown here before October 14, so it has to follow a crop that is finished by then.Crimson clover flower, Photo Kathryn Simmons
Before our change to the newStep 7 Including rotation, we had been planting ourNo-till crops tomatoes and peppers into a mowed cover crop of winter rye and hairyWinter rye and hairy vetch. PhotoKathryn Simmons vetch. We like this no-till method and wanted to incorporate it into our new scheme too. This reduces inversions of the soil, and the vetch (if plentiful) can supply all the nitrogen the tomatoes need. Rye and vetch is best sown here in early to mid-September, creating another restriction on which crops the tomatoes could follow. These “restrictions” are more like the rules to a game, providing a structure to work within.
Step 5 revisited. Determine sequences including cover cropsWe formed several “strings” of a few crops-and-cover-crops that followedeach other well: Spring broccoli can be followed by rye and vetch in good time to grow a thick stand for the no-till tomatoes the next year. Late corn can be undersown with oats and soy to provide a winter cover crop that is easily incorporated before a March planting of potatoes. The early corn can be followed by fall garlic planting. Then the garlic harvest can be quickly followed by fall carrots. Mid-season corn is finished in time to establish rye and crimson clover, which will do well and produce lots of nitrogen and biomass before we need to plant the June potatoes.After some shuffling of paper pieces, we came up with a workable sequencefor all the major crops, and also a transition plan for a couple of years to getus onto the new rotation.
Popping in some summer cover cropsIf we have a four week gap between crops in warm weather, we sow buckwheat.If we have 6 weeks, we sow soy with buckwheat.Japanese MilletSorghum-sudangrass Shown here after mowing. Photo Kathryn Simmons
Floating stringsSpring broccoli can be followed by rye and vetch to growa thick stand for no-till tomatoes the next year. Late corn can be undersown with oats and soy fora winter cover crop that is easily incorporated before March potatoes. Fall garlic can follow early corn.Fall carrots can follow garlic.Mid-season corn is finished in time to establish rye andcrimson clover, to produce lots of nitrogen and biomassfor June potatoes.
Nailing down the corn, the nightshades and their next-of-kinLate corn Middle corn Early corn Springundersown with oats planting followed by broccoliand soy, easily followed by fall planted followed byincorporated in early rye and garlic on half rye andspring crimson the plot. vetch clover Other half?March June Overwintered No-tillplanted potatoes. planted garlic tomatoes potatoes followed by and peppers fall carrots. Other half?Still looking for homes:wintersquash, watermelon, sweet potatoes, fallbrassicas
Step 8. ImprovementsWe found a few improvements: We discovered Austrian winter peas as a leguminous cover crop. They are said to reduce the incidence of Septoria leaf spot in following tomato crops, so we now include them in our no-till rye and hairy vetch planting. AWP can be sown as late as 11/8 here, so we add them to our later rye and wheat cover crop sowings. We found we could tighten up the rotation by having more than one vegetable crop in a plot within the year. We follow the spring planted potatoes with the fall broccoli and cabbage transplanted in July/August. This lets us keep a 10-year cycle round the 10 plots while having one plot in cover crops all year round, to replenish the soil.Fall broccoli undersown with clover mix. Photo Twin Oaks Community
Step 8. Improving the All Year Green Fallow We now undersow the fall brassicas with a mix of clovers (white, red and crimson) about a month after transplanting. The following spring, we bush hog the old brassica stumps and let the clover flourish. We have contingency plans: In spring, once the warm weather has arrived, if the weeds are too bad, or the clover stand not thick enough, we turn the clover under and sow sorghum-sudangrass hybrid with soy. This gets mowed to a foot (30 cm) when the sorghum-sudan is four feet (1.2 m) tall, to encourage deeper rooting for better soil drainage, and can stay until killed by the frost. If the plot is looking good, we let the clover grow all summer, mowing to prevent the crimson clover seeding. In August, we review again: if we still have the clover we may turn it under and sow oats. Or we may leave it over winter. And so we get two food crops in one year and none the next from that plot. Plus it is ready early the following year for our first corn planting.
Step 8. Sweet corn → oats →garlic →buckwheat →carrotsAnother example of a tightrotation: Garlic Harvest, Photo Rayne Squier After early corn, sow oats and divide the plot in two. Use half for the next year’s spring broccoli Mow the other half from time to time until late fall, then disk and plant garlic there. Harvest the garlic in June, sow buckwheat and soy, Then sow fall carrots in late July or early August. That half-plot grows three food crops in two years.
Late corn Middle corn Early corn Spring broccoliundersown with planting followed followed by fall followed by rye,oats and by rye and Nearly There planted garlic on vetch andsoy, easily crimson clover half the plot. Austrian winterincorporated in Other half in oats. peas in earlyearly spring SeptemberMarch June planted Half in No-till tomatoesplanted potatoes overwintered and pepperspotatoes, harveste garlic followed byd in July fall carrots. Other half for spring broccoli and cabbageJuly planted fall Brassicas followedbrassicas by rye, vetch andundersown with Austrian winterclovers peas in early September (return to top of column 4)All Year Cover Still looking forCrops (Green homes:Fallow) winter squash,Followed by early watermelon,corn (return to top ½ plot of sweetof column 3) potatoes
A less perfect piece• We decided to abandon our latest corn sowing and give that half plot to sweet potatoes. It works in terms of allowing the preceding cover crop time to flower, but doesn’t work so well in terms of sowing oats before next years spring potatoes. So we follow the sweet potatoes with wheat.Sweet potatoes and late corn. Photo Bridget Aleshire
Having the rotation in a useful format• We drew up our ten-year rotation on a piece of card with a small central disk attached by a brass paperclip so it can rotate each year to show which crops will be planted in which plots. We call this our Rotation Pinwheel• We are still using the same piece of card we made in 1996, even though we started our second ten year sequence in 2006. It has seen quite a bit of White-Out!• For my book, the publishers’ re-drew it tidily.
Map the cropsOn a blank map of the plots we write in whichmajor crops will go in which patch, using the ten-year Rotation Pinwheel. We block in the areaneeded for each major crop (checking our CropReview notes for changes in amount to plant) andcalculate the remaining space in each plot. Our tenplots are not exactly the same size and our maincrops don’t all need equal space either, so someplots will have spaces of various shapes and sizesand others no gaps at all.
Planning the tractor workIn the margins of our maps, we write when Spring broccoli transplant, Photo Kathrynthat patch will need disking or other tractor Simmonswork. Usually we have five spring diskings:1. As soon as possible in February, for the spring broccoli, cabbage and potatoes;2. In mid-March, for the 2 early corn sowings;3. In mid-April, for watermelon, peppers, winter squash and sweet potatoes;4. In mid-May, for summer potatoes and middle three corn sowings;5. In mid-June, for the late corn.
Factors in planning tractor work• minimizing the number of disking occasions, to make tractor drivers’ lives easier;• waiting until legumes flower, if we can, before disking, to get maximum value from the winter cover crops;• disking far enough ahead of planting to allow the cover crop to break down in the soil (dead oats are relatively quick, while rye takes more than three weeks).A cover crop of rye, hairy vetch and crimson clover. Photo Kathryn Simmons
Fitting in succession crops Next we look for any extra space in the plots, to fit in the minor crops: succession plantings of beans, summer squash and zucchini, cucumbers, edam ame, cantaloupes and anything we didn’t manage to find room for in the permanent raised beds. Green beans, Photo Kathryn Simmons
Succession CropsPlanning ChartWe list the sparespaces in the plots (inorder of availability)and the crops we hopeto plant (in dateorder). At thebeginning and end ofthe season, and inmid-season whenspace in the main plotsis tight, we also lookfor spaces in our raisedbeds. Then we pencilin arrows, fitting thesuccession crops intothe spaces available.
Opportunities for planting cover crops Undersowing at last cultivation (oats and soybeans in corn shown here.) After vegetable crops, in summer or fall In spring, between an early vegetable crop and a later one After long season crops, for winter Late winter or early spring, if the area will not be planted with vegetable crop until late spring. We use oats. Frost-seeding of small seeds such as clover: Broadcast in the early morning, when ground is frozen. As it thaws, the water draws the seeds down into the soil. Works well for clovers. To replace a crop failure. Photo Kathryn Simmons
Fitting the cover crop with the goal• Smothering weeds: sorghum-sudan, cereal rye, buckwheat, brassicas (we don’t do brassica cover crops – rotation, bugs).• Fixing nitrogen: clovers, vetches, Austrian winter peas, cowpeas, soybeans, lentils, sunn-hemp.• Scavenging leftover nutrients : small grains, brassicas, annual ryegrass (we don’t use annual ryegrass either – danger of it becoming a weed)• Improving soil drainage: sorghum-sudangrass, sunflower, daikon, sweetclover, alfalfa, brassicas, sugar-beet (never tried that.)• Grazing: brassicas, clovers, small grains, annual ryegrass, sorghum-sudan• Bio-fumigation: brassicas, sorghum-sudan, sunn-hemp, sesame• Killing nematodes: Ida Gold and Pacific Gold mustards, white lupins, Iron and Clay cowpeas, OP French marigolds, sesame
Incorporating cover crops• If possible grow to early bloom for max biomass• Incorporate before plants set seed• Mow with a rotary mower (eg bush hog) which chops the plants into small pieces. (Scissor-bar mowers and scythes leave long strawy plants)• Shallow tilling, put cover crop where soil life is most active, not deeper.• If direct-sowing, incorporate 3-4 weeks before sowing date.
Benefits of planned crop rotationsThis tight crop planning might sound laborious or mind-boggling,but for us it’s very worthwhile. The division of the gardens into 10 plots gives us mental and psychological advantages - we don’t have to think about the whole of the area all of the time. In spring we “open up the rooms” one or two at a time to plant. By the beginning of July everywhere is in use In August we start to put the plots “to bed” with their winter cover crops. Annual expansion and contraction of the space needing our attention helps us to stay sane and focused and keep perspective. This system helps us get high productivity from our land, while taking good care of it.
Perhaps you have lots of land?• At Twin Oaks the land available for vegetable Crimson Sweet watermelon, Photo Kathryn Simmons gardening is finite. The whole community would want to consider any application from us to expand the area we use. All the other fields are fully used, for grazing or for hay. We’re not enthused about clearing woodland.• Years ago, researching plant spacing for watermelons, (trying to plant as closely as possible while keeping the melon size and yield up) I spoke with a farmer in the Midwest.• He said if farmers in that region wanted more watermelons, they would just plow up more land, not try to plant them closer. That was a useful perspective for me to consider.• Here on the East Coast, land for farming is less available and more expensive.• I come from the UK, where land is even more expensive.• If you have lots of land, you might prefer bio- extensive planting
DisadvantagesProbably the biggest snag for us in using this rotation is: it doesn’t take into account that parts of the gardens with poor drainage are less suitable for some crops.One year tomatoes were going in one of our potentiallywetter areas. El Nino - wet spring! So the previousfall, before sowing our cover crop, we made raised beds.We mowed the no-till cover crop, crossed our fingers andplanted. As it happened, no wet spring! For us, making temporary beds or planting on ridges in the wetter areas is easier than changing the crop rotation.
Resources 1 The New Organic Grower, Eliot Coleman, 1995, Chelsea Green ATTRA Market Farming: A Start-up Guide, www.attra.ncat.org/attra- pub/summaries/summary.php?pub =18 ATTRA Scheduling Vegetable Plantings for a Continuous Harvest, www.attra.ncat.org/attra-pub/summaries/summary.php?pub=20 ATTRA Intercropping Principles and Production Practices (mostly field crops, but the same principles apply to vegetable crops), www.attra.ncat.org/attra-pub/summaries/summary.php?pub=105 SARE at www.sare.org -A searchable database of research findings Available to download: Using Cover Crops Profitably, Crop Rotations on Organic Farms, A Planning Manual, Charles Mohler and Sue Ellen Johnson, editors. SARE Kerr Center 2011 Organic No-Till Pumpkins Report http://www.kerrcenter.com/publications/Pumpkin-Organic-No-Til- Demo-Report-2012.pdf
Resources 2 Growing Small Farms: www.growingsmallfarms.org Click Grower Resources, Farm Planning and Recordkeeping Adams-Briscoe Seed Company www.abseed.com Daniel Parson, Planning the Planting of Cover Crops and Cash Crops, SSAWG 2012 www.slideshare.net/parsonproduce/southern-sawg Joel Gruver, Cover crops for vegetable cropping systems www.slideshare.net/jbgruver/cover-crops-for-vegetable-crops Joel Gruver, Finding the best fit: cover crops in organic farming systems. Some overlap with previous slideshow. www.slideshare.net/jbgruver/cover-crops-decatur Brad Burgefurd, Cultural Practices And Cultivar Selections for Commercial Vegetable Growers. Wide scope. www.slideshare.net/guest6e1a8d60/vegetable-cultural-practices-and- variety-selection