Tuesday, October 29, 2013

Can you really grow all your own food for a year in 700 square feet?




A time-honored response to economic distress and uncertain times is to start or expand a vegetable garden. After all, we have to eat, and food purchases account for a considerable percentage of our expenditures, even with subsidies to large agribusiness concerns that drive down that percentage. Sharon Astyk and Aaron Newton, in their book A Nation of Farmers, document how the victory gardens of World War II supplied a surprisingly large amount of the fruits and vegetables eaten during that time.1 Small city gardens and backyard livestock still supply good-sized percentages of vegetables and meat in large cities such as Hong Kong.2 Following the economic crisis of 2008, Fedco Seeds, a small seed company in Maine, experienced rapidly growing sales.3

Just because more people may be gardening or may have enlarged their gardens, however, does not mean that they are gardening in the most beneficial way, for themselves and for the ecosystem of which their backyard is a part. While there is a considerable body of information in book and online form about backyard gardening, including information available from the U.S. Department of Agriculture in the form of state Extension publications for home gardeners that help gardeners respond to issues specific to their region4, little of it is devoted to how to raise foods that offer the highest value in calories and nutrition for the space used. Since growing staple foods has become almost entirely the responsibility of agribusiness, backyard gardeners have concentrated on crops such as lettuce, tomatoes, peppers, cooking greens, snap beans and peas, sweet corn, and culinary herbs. Most haven’t concerned themselves with growing calorie-dense crops, primarily root and dry seed crops, because these are widely available at low cost from agribusiness and its distributors and retailers. Gardeners prefer to grow the more perishable crops that do well in small spaces, often taste better grown and consumed fresh than do the multiple-day-old versions available through the agribusiness chain, and cost more to purchase from a local farmer than to grow themselves. While this is a reasonable way to garden for people with limited time to devote to gardening and sufficient income to purchase most of their food supply, it will not scale up well to providing a sizable fraction of the calories and nutrition a person requires in a year. For that a different range of crops must be grown and gardening techniques adapted to produce them at the times and in the amounts needed.

Ecology Action, a not-for-profit organization based in Willits, California, has since its inception focused on how to raise substantial amounts of nutritious, calorie-dense food in backyard-sized plots. Its 1985 publication One Circle: How to Grow a Complete Diet in Less than 1000 Square Feet by David Duhon describes the theory behind developing a vegan diet that can provide all of the calories and nutrients needed by an adult in a year. Duhon considered a suite of crops that when grown according to the methods developed by Ecology Action and described in its publication How to Grow More Vegetables by John Jeavons (hereafter designated as HTGMV), could provide that vegan diet for both men and women while requiring a garden size of no more than 1400 square feet per person.5 (While Duhon also proposes garden plans for complete vegan diets that might be grown in as little as 550 square feet [the woman’s plan] and 800 square feet [the man’s plan], the average of which accounts for the 700 square feet of numerous later references to his work including the title of this report, both diets are very limited and the garden plans do not include the same crops. The 1400 square foot garden plans use the same suite of crops for both men and women, the suite of crops included is wider, and the crops used for the 1400 square foot garden plans are also used in the smaller garden plans. Any issues with yield, for instance, that affect the 1400 square foot garden plans will also affect the smaller garden plans. Thus I have chosen to evaluate the 1400 square foot garden plans in this report rather than the smaller garden plans.) The two suites of crops, one for northern areas and one for southern areas, are shown in Tables 1 and 2.

Table 1. 1400 square foot complete-diet garden, northern version
Crop
Number of crops grown per year
Assumed yield lb/100 sq ft
Crop area for women, sq ft
Crop area for men, sq ft
Wheat
2
10
500
675
Garlic
1
120
25
34
Sunflower seeds
2
5
50
68
Potatoes
2
200
225
304
Onions
2
400
25
34
Parsley
2
35
50
68
Turnips
2
200 greens, 70 roots
25
34
Collards
1
300
25
34
Parsnips
2
238
25
34
Filberts
1
12.4
240
324

Table 2. 1400 square foot complete-diet garden, southern version
Crop
Number of crops grown per year
Assumed yield lb/100 sq ft
Crop area for women, sq ft
Crop area for men, sq ft
Sweet potatoes
1
82
325
439
Soybeans
1
8 (dry)
75
101
Potatoes
2
200
250
338
Sunflower seeds
2
5
50
68
Peanuts
1
10
250
338
Turnips
2
200 greens, 70 roots
25
34
Onions
2
400
15
20
Wheat
2
10
100
135
Parsley
2
35
15
20
Garlic
1
120
38
51
Leeks
1
240
25
34


Because the average residential home sits on slightly less than ¼ acre (approximately 10,000 square feet) of land6, Duhon’s minimum-area garden plans could put the growing of a full diet within range of a good-sized fraction of U.S. residents. However, a careful reading of One Circle reveals that Duhon does not claim to have planted and eaten for a year from such a garden, thus it does not document that the assumed yields upon which the garden plans depend have been obtained by Duhon or by anyone else at Ecology Action.7 The value of the book rests with the nutritional analysis that Duhon has done and the way in which he has used nutritional needs and the postulated yields obtainable by Ecology Action’s methods to develop some versions of very small gardens that can meet those needs. He has also addressed how one might transition to a diet based on only those foods while one is developing skills with the methodology that Ecology Action espouses. However, I am aware of no reports from gardeners who have attempted to grow the complete-diet gardens in Tables 1 and 2 to determine if in fact the crop yields required for them can be obtained under their conditions.8

Later work by Ecology Action suggests that a larger area, anywhere from 2,500 to 4,000 square feet or more, will be required for a garden that produces all of its own compost material for maintaining fertility as well as sufficient calories and nutrition for one person’s survival. In such a garden about 60% of the area would be used to grow grain and seed crops for calories and compost material, about 30% of the area would be planted in high-calorie root crops such as potatoes and sweet potatoes, and the remaining area would be planted to vegetable crops for vitamins and minerals.9 Ecology Action’s 2003 publication Designing a Grow Biointensive Sustainable Mini-Farm offers a template for design of a backyard garden to meet dietary needs and sustainability concerns.10 However, without knowledge of the yield obtainable per unit area of each crop in one’s own conditions, it will be impossible to determine if in fact one can grow most to all of one’s own diet on a backyard scale, whether at the smaller size of Duhon’s designs or at the larger scale that Ecology Action now promotes as necessary for sustainability.

In this report I will discuss my efforts as a scientist-gardener to determine the yields I can obtain for the suites of crops suggested by Duhon as a contribution toward developing a prototype minimum-area sustainable garden plan applicable to the region in which I live. By doing so I hope to encourage other scientists who also garden, as well as new and experienced backyard gardeners, to work together to develop and publicize similar plans for the regions in which they live. In the ongoing descent, Astyk and Newton argue, we’ll need 100 million people in the U.S. to take at least some role in raising their own food, to help cushion the blow from erratic employment, rising food prices, and weird weather patterns and other environmental responses to damage caused by human activities.11 If by our example we can show the usefulness of the scientific method to helping people grow most or all of their own food on backyard-scale plots, we may get the scientific method into more hands and in a hands-on way. This could contribute to getting the scientific method through the Long Descent12 as well as provide some measure of food security for anyone who takes up gardening in this way.

Method

The garden is located in Spanish Lake, Missouri, an unincorporated area in northeastern St. Louis County near the confluence of the Missouri and Mississippi Rivers. The geological history of the area includes periods of time when winds deposited glacial loess over the existing land surface.13 As a result the garden soil consists of a very deep, moderately well-drained, moderately permeable loess-derived silt loam and silty clay loam.14

Each garden bed is 4 feet wide by 25 feet long for a total bed area of 100 square feet; fifteen such beds are currently in production. The garden area slopes slightly to the east and south and is in nearly full sun during most of the growing season, which lasts from approximately mid-March till mid-November; the frost-free portion of the season is from sometime in April through sometime in October. In 2013 the last spring frost occurred on April 20 and the first fall frost occurred on October 25. When needed, supplementary water is applied from the municipal water supply, or if a small enough amount is needed (for instance, for a small area of newly-planted seeds or seedlings), from previous rainfall stored in rain barrels.

To prepare each garden bed for planting I apply compost made from kitchen wastes, garden wastes, and autumn leaves that have been piled in unmeasured proportions and allowed to remain piled without turning for a few to several months until use. While the amount of compost I apply to each garden bed has varied over the years according to changes in the recommendations in successive editions of HGTMV, it has ranged from 15 to 20 gallons of compost per 100 square feet. The amount and kind of organic fertilizer applied to each bed has varied from bed to bed and from year to year. After applying compost and any fertilizer, I dig in these materials to a depth of approximately 12 inches with a shovel or a broadfork15, rake the bed smooth, and then plant seeds, seedlings, or roots according to that year’s garden plan for that bed. Seeds, potato starts, and sweet potato slips are procured from a variety of small seed companies. Seedlings are grown on site. Garlic and potato onions are replanted from the previous year’s harvest.

Varieties, crop spacings, and planting dates for each crop from Tables 1 and 2 are given in Table 3 for the 2013 growing season and for the growing season in which I obtained the highest yield if different from 2013. The HTGMV spacing column reports the spacing in inches that is recommended for that crop in the 8th edition of HTGMV. In the actual spacing column HTGMV means planted on the triangular spacing recommended by HTGMV with spacing between plants given in inches. In the date planted column TP means transplanted for those crops transplanted as seedlings.

Table 3. Planting data for each variety of the crops given in Tables 1 and 2.
Crop
Variety
HTGMV spacing, inches
Actual spacing, inches
Date planted
2013 spacing, inches
2013 planting dates
Garlic
Inchelium Red
4
4, HTGMV
11/16/1999
6, HTGMV
11/10/12
Potatoes
Rose Gold
9
9, HTGMV
4/7/2006



Elba



In-row 12, between-row 24
5/1

German Butterball



In-row 12, between-row 24
4/30
Onions
Potato (multiplier)
Not given
6, HTGMV
11/26/2005
8, HTGMV
11/10/12

Rossa di Milano
4


In-row 6, between-row 12
4/24
Parsley
Gigante d’Italia
5
*
Sown 2/4/2008, TP 4/23/2008


Turnips
Purple Top White Globe
4
In-row variable, between-row 6
8/16/2008
In-row variable, between-row 12
8/16
Collards
Even’Star Champion
12
12, HTGMV
Sown 2/1/2009, TP 5/17/2009
In-row variable, between-row 12
8/7
Sweet potato
Ivis White Cream
9
In-row 15, between-row 24
6/21/2008



O’Henry



In-row 12, between-row 48
5/29
Soybean
Asmara
6
**
7/2/2011
**
6/16
Leeks
Giant Musselburg
6
6, HTGMV
Sown 2/1/2006, TP 4/14/2006



Bleu de Solaize



In-row 6, between-row 12
Sown 1/22, TP 4/24
Peanut
Tennessee Red Valencia
9


In-row 12, between-row 24
6/3
Wheat
Hard Red Winter
5


Broadcast
11/16/2012
*Parsley: 4 plants per square foot
**Soybean: 4 seeds per square foot


For some crops I plant a certain number of seeds or seedlings in a square foot instead of using the triangular spacing recommended by HTGMV. Some crops are planted in rows across the short dimension of the bed (turnips, leeks, bulb onions) or the long dimension (peanuts, potatoes, sweet potatoes). For those crops both the in-row and between-row spacings are given in inches. For some crops the in-row spacing is variable and is so noted.

Planting information, including the number of square feet planted and the weights harvested on each harvest date as measured with a 0-5 pound or 0-25 pound scale, are recorded separately for each variety of each crop. At the end of the growing season the total harvested weight is obtained by summing the weights measured on each harvest date. For each different variety of each crop the total harvested weight and the area planted are used to compute the weight harvested per square foot of garden space planted to that variety. The weight per square foot is multiplied by 100 to obtain the weight per 100 square feet for comparison with Duhon’s assumed yield for that crop.

Results

In Tables 4 and 5 the yield assumed by Duhon for each crop in the 1400 square foot complete-diet gardens is contrasted with the best yield I have obtained for that crop from 2000 through 2013. I have also reported the 2013 yield for those crops for which the growing season is complete as of this writing.

Table 4. Yields obtained for northern version crops
Crop
Assumed yield lb/100 sq ft
My best yield lb/100 sq ft
2013 yield
lb/100 sq ft
Wheat
10
*
Not yet processed
Garlic
120
39
12
Sunflower seeds
5
**
Not grown
Potatoes
200
111
75, Elba



38, German Butterball
Onions
400
78
33, potato



34, Rossa di Milano
Parsley
35
84
Not measured
Turnips
200 greens, 70 roots
101 roots
Still growing
Collards
300
66
Still growing
Parsnips
238
Not grown
Crop failure
Filberts
12.4
**
**
* grown in some years but no yield data was recorded
** unable to obtain yield
   
Table 5. Yields obtained for southern version crops
Crop
Assumed yield lbs/100 sq ft
My best yield lb/100 sq ft
2013 yield lb/100 sq ft
Sweet potatoes
82
74
64
Soybeans
8 (dry)
41 (green)
Crop failure
Potatoes
200
111
75, Elba



38, German Butterball
Sunflower seeds
5
*
Not grown
Peanuts
10 (dry)
Not grown
9.6 (wet)
Turnips
200 greens, 70 roots
101 roots
Still growing
Onions
400
78
33, potato



34, Rossa di Milano
Wheat
10
**
Not yet processed
Parsley
35
84
Not measured
Garlic
120
39
12
Leeks
240
107
Still growing
* unable to obtain yield
** grown in some years but no yield data was recorded

Discussion

It is evident from Tables 4 and 5 that except for parsley, turnip roots, sweet potatoes, and perhaps soybeans and peanuts depending on the green/dry weight ratio, I have been unable to obtain yields as much as half that required for Duhon’s 1400 square foot complete-diet gardens. For some crops I have been unable to obtain a yield at all. Only for parsley and turnip roots have I obtained better yields than those assumed by Duhon in developing his minimum-area garden plans.

Possible explanations for being unable to obtain the yields assumed possible by Duhon include gardener error in applying HTGMV’s particular method; other poor gardening practices; poor choice of crop varieties; soil deficiencies; losses to animals; and climatic factors and other possible problems with the yield assumptions Duhon made to develop the garden plans. Each of these will be examined in turn.

Errors in applying HTGMV’s method. The hypothesis of gardener error in applying HTGMV’s method gains merit when examining Table 3, which reveals that in many cases I have been planting at wider spacings than those suggested by HTGMV and than I have used in the year during which I obtained maximum yield. A wider plant spacing generally translates into reduced yield since yield is measured in weight per unit area and a wider spacing means fewer plants per unit area. However, previous experience in using the crop spacings suggested in HTGMV for those crops have shown that the wider plant spacings make up for reduced yield by improving other aspects of planting and caring for the crop. I have discussed elsewhere how I have changed my gardening methods as my garden size has increased.16 HTGMV was originally designed for very small gardens in the tens to a few hundreds of square feet, where it is easier to work at small plant spacings. Weeding between onions planted at a 4 inch spacing, for instance, means pulling individual weeds while kneeling in a 12-inch-wide path as hoes small enough to fit between the plants do not exist. The difficulty in doing this, and the time required to do it, led me to work at the wider spacings shown in Table 3 for many crops. To the extent that other people also experience these difficulties it suggests that a minimum-area garden, even if it uses the same suite of crops as Duhon proposes, will require more area than Duhon’s plans provide to grow the required weight of each crop.

Other possible sources of error in applying the HTGMV method include not properly fertilizing the garden beds before putting them into production; not producing the quality of compost needed to maintain intensive production; and not planting in synergistic combinations so plants can enhance each other’s growth. The error of not properly fertilizing at the outset will be addressed more fully later on. Compost quality depends in part on proper initial fertilization and also, according to HTGMV, on using their technique for creating properly cured compost.17 I find the method too complex to apply as I often do not have the required ratios of green and dry plant wastes on hand as the piles are being built. Thus my compost is likely to be of lower quality than the HTGMV method claims is required for achieving yields in the medium range (the assumed yields in Duhon’s plans). “Synergistic plant combinations” includes aspects such as crop rotation and companion planting that affect interactions between plants.18 Although I have developed a workable crop rotation plan, I have neglected other aspects of companion planting. However, Duhon’s garden plans will not be able to draw on much of the companion planting lore and may not allow for optimum crop rotation, suggesting that they may also be subject to lower yields than Duhon assumed.

Other poor gardening practices. These include not planting at the proper time for this location and not keeping the planted crop properly weeded. An examination of the planting dates in Table 3 in comparison to Missouri Extension’s suggested planting dates for this area19 indicates that I am likely planting too late for the highest yields in bulb onions, leeks, and potatoes. I am aware of this but have had difficulty planting early crops like these at the proper time. The potato starts do not arrive before April 10 from their source in Maine. Spring rains are often heavy, and cool soil and air temperatures mean that the soil may be too wet to work when the preferred planting window arrives. These factors may reduce the obtainable yield for this area to below Duhon’s assumptions for his minimum-area gardens, thus requiring an increase in the size of the garden to obtain the crop weight needed for the diet.

Weeding has been a continual challenge, one that I acknowledge I have not met well. Besides often not weeding in a timely manner, I compound the error by composting weeds that have gone to seed, ensuring that more weeds will germinate in future years. The size of the garden is a major factor. When I had only a hundred or so square feet of vegetable garden space it was easy to keep even closely spaced plantings weeded. A large (by most people’s expectations) backyard garden, a crowded planting schedule, a life beyond the garden, and a tendency to put off weeding when there is a conflict between it and other aspects of the garden and of life have conspired to lead to excessive weediness and probable loss of yield in my garden. As with planting dates, my difficulties may be shared by others attempting to grow the crops for a minimum-area garden in this region and should be reckoned with in the garden design.

One way to determine if poor general gardening practices are a factor in the low yields I obtain is to compare them with yields obtained by other gardeners or by farmers in this area. However, the Missouri Extension’s expected yield information is based on row feet of garden space. It is not clear how to translate row feet of yield into yield per unit area since only the length of the row and not its width is given.20 I have been unable to find a source that lists expected yields in weight per unit area for vegetable crops grown in the lower Midwest.

Poor choice of crop varieties. The possible yields given in HTGMV for each crop do not indicate that variety chosen may affect yield. Farmers and gardeners observe that some varieties of each crop yield better than others under their conditions. The effect of variety can be dramatic, as shown in Tables 4 and 5 for two different potato varieties planted in 2013 on the same spacing and in beds prepared and fertilized in the same manner. It may be that if I chose the best-yielding variety for each crop, I could achieve the mid-range yield that Duhon assumes for his garden plans. To date I have not been able to locate quantitative information on the highest-yielding varieties for Midwestern gardens. Seed company claims that particular varieties are “productive” do not include the kind of quantitative information that I have provided in Tables 4 and 5. Without this information we cannot determine if Duhon’s yield targets can be achieved with some varieties but not others.

Soil mineral deficiencies. Another factor that may reduce the yields I obtain is an unbalanced soil mineral base. Ecology Action recommends obtaining a professional soil test prior to first preparing each bed and adding organic fertilizers as needed to bring nitrogen, phosphorus, potassium, and pH to the level recommended by the testing organization for a vegetable garden. While I had a soil test done by the Missouri Extension and followed its recommendations when I prepared the first garden bed, I did not follow its recommendations when first preparing subsequent beds. Instead I used a generic organic fertilizer blend of 4 quarts of cottonseed meal, 1 quart of garden lime, 1 quart of hard rock phosphate, and 1 quart of greensand, mixed together and applied to 100 square feet, when I added fertilizer at all.21 Steve Solomon offers a more nuanced view of soil mineralization and how to bring it to optimum levels in his latest book The Intelligent Gardener.22 In April 2013 I had the garden’s soil tested by the laboratory Solomon recommends. The results indicated that the soil is excessive in potassium and magnesium and deficient in the other minerals tested for. As a result, I developed a different blend of organic fertilizers that more specifically addressed the soil’s mineralization needs, following Solomon’s suggestions.23 I hypothesized that yield, taste, and pest and disease pressure might improve in 2013 as a result.24 For the crops in Tables 4 and 5, the lower yield seen this year is at least partly due to increased spacing in 2013 versus the year in which the highest yield was obtained, as shown in Table 3. Because the spacings were different it is not possible to determine if remineralization affected yield. For taste and pest/disease pressure, little if any difference was noted in the crops in Tables 4 and 5. Thus the effect of soil remineralization is inconclusive for the crops reported in Tables 4 and 5.

Losses to animals. In some cases, as with sunflower seeds and filberts (hazelnuts), animals have eaten most or all of the crop before it was ready to harvest. Squirrels and birds have been observed to feed on these crops, and other animals may be feeding on them as well. Until I can find a way to protect aboveground seed and nut crops sufficiently to retain most of the yield, I cannot grow these crops. Since peanuts form underground and no underground pests caused excessive crop loss this year, peanuts may prove to be a more useful seed crop for my minimum-area garden than sunflower seeds or filberts.

Other factors. Duhon’s minimum-area garden plans were based on nutritional analyses and the expectation of Ecology Action that experienced gardeners should be able to obtain yields two to four times that which is typical of conventional agriculture.25 They do not appear to take climatic factors into account. While a climate with a long, cool summer is ideal for potatoes and would be reasonably expected to produce a higher yield of potatoes per unit area than a climate with only a short period of cool weather followed by a long and hot summer, Duhon’s northern and southern garden plans assume the same yield is obtainable for each. My experience is that it is difficult to achieve Ecology Action’s mid-range yields for most crops that prefer long, cool growing seasons, while it is easier to achieve those yields for crops that grow well in a long, hot growing season. This matches climatic patterns for my location in east-central Missouri. Duhon’s northern and southern plans attempt to take advantage of the length and warmth of the growing season by the choice of crops, but because the southern suite still includes crops like onions and potatoes that prefer cooler conditions and assumes that yields will match those of crops grown in the conditions they prefer, it may not be realistic in its area expectation. Table 5 shows that my yields for crops that grow well in hot-summer climates are generally closer to Duhon’s expectations than for those crops that prefer cooler summers, in support of my argument.

Duhon’s southern plan requires that 433 square feet of the garden area be planted to both a warm season and a cool season crop during the growing season. For the double-cropped area he proposes that the warm season component would include 233 square feet of sweet potatoes, 100 square feet of peanuts, and 100 square feet of sunflowers. The cool season components would include 153 square feet of fall potatoes, 25 square feet of spring turnips, 25 square feet of fall turnips, 15 square feet of spring parsley, 15 square feet of fall parsley, and 200 square feet of winter wheat.26 Because the frost-free growing season is only about six months long and both spring and fall are short in this area, there is insufficient time in the growing season to permit Duhon’s double-cropping scheme without using season extension tools such as cold frames or hoop houses. For those of us who do not practice season extension it will be necessary to increase the garden area to avoid planting the same beds or portions of beds to more than one crop during the growing season.

It is evident from the plans that a diet based on them will be monotonous. Astyk has discussed the difficulty that many people have in changing their diet even when the necessity is obvious.27 Although the idea of a minimum-area garden is valuable, I suspect that its acceptance will require a more varied diet than Duhon’s proposed plans will allow and thus a larger garden area since crops with lower calorie and nutrition yields per unit area will be included.

Finally, Duhon’s plans were developed before Ecology Action proclaimed the necessity of devoting a large proportion of the growing area, as much as 60%, to grain and other high-carbonaceous-material crops in order to grow enough carbon to make enough compost to sustain the garden’s fertility through time.27 Duhon’s southern plan plants only 34% of the area to the carbonaceous material producing crops of wheat, soybeans, peanuts, and sunflowers, thus the yields may not be sustainable year after year if the only source of fertilizer is the compost made from garden and kitchen wastes.

To address the various issues discussed above I am developing a garden plan suited to this area that includes a larger variety of crops than Duhon includes in his garden plans while working toward the sustainability goal that Ecology Action espouses and improving my gardening skills in the process. The current plan consists of a total of 15 beds (1,500 square feet), planted in five groups of three 100 square foot beds each. The groups of beds, named after their main crops, rotate throughout the garden on a five-year schedule and include the following crops in 2013.
            Grain group: flint corn
            Legume group: cowpeas, edamame-type soybeans, peanuts, dry beans, shell peas, snow peas
            Cucurbit group: potato onions, garlic, and winter wheat planted the previous winter and harvested in early summer, followed by summer squashes (Cucurbita pepo), winter squashes (C. maxima and C. moschata), muskmelons, cucumbers
            Solanum and morning glory group: potatoes, tomatoes, sweet and hot peppers, eggplants, tomatillos, ground cherries, sweet potatoes, basil
            Green and root vegetables: lettuces, cabbages, collards, kale, broccoli, bok choy, turnips, rutabagas, storage radishes, carrots, beets, parsnips, parsley, cutting celery, bulb onions

Compared to Duhon’s southern complete-diet plan, this plan offers a much higher variety of crops for the gardener to eat, at the price of growing a large area to crops of lower calorie and/or nutrient density. Thus it cannot provide all the calories and nutrition that the two adults who eat from it require, though we eat a substantial fraction of our diet from the garden from June through December and a smaller fraction during the rest of the year. Compared to Ecology Action’s sustainable garden plan, the total of 40% of the garden area planted to grains and legumes is less than the 60% of the garden area that Ecology Action suggests, though it is more than the 34% in Duhon’s southern plan. Of the crops Ecology Action currently recommends for the 30% of the area to be grown in high-calorie root crops29, the plan includes only potatoes, sweet potatoes, leeks, and garlic planted to a total of 216 square feet in 2013, for only 14% of the garden area. The remaining 46% of the area is planted to crops placed in the vegetable crop category that Ecology Action recommends should take up only 10% of the garden area. Again this comes at the price of lower caloric and nutrient density, but with the advantages of good garden rotation practice (the time between the same plant family in each bed is five years) and a higher variety of crops available throughout and, by proper storage techniques, beyond the growing season. At the time of writing the 2013 growing season continues. After it ends, I will post the results for each crop and a discussion of the overall garden performance and its effect on my planning for future years in my blog, Living Low in the Lou.30

Future work

Much work remains to be done to develop garden plans that provide significant amounts of calories and nutrients for the gardener, are adaptable to backyard-sized plots, follow good gardening practices, and produce a wide variety of foods the gardener will actually eat over the growing season and beyond. As this report has demonstrated, one of the linchpins of this effort is to obtain the yield per unit area for the various crops and varieties that are grown in specific regions. I have made some such information from my scientific gardening practice available in this report and will post more information to my blog as it becomes available.

However, I am only one gardener in one region. If there were more gardeners here in the St. Louis region interested in gardening this way, we could run variety trials to find high-yielding varieties that would let us raise more high-calorie, nutritious food on the same amount of land. We could run spacing trials to determine the optimum spacing for each different crop. We could develop garden plans for our region that marry eater desires for variety with good gardening practices and sustainability concerns. We could inform each other of our gardening failures, analyze them, and learn from them to become better gardeners individually and as a group. Gardeners in other regions could do similar things and should because something that works here won’t work everywhere else.

What I have described is the application of the scientific method to gardening. It requires little in the way of equipment and prior knowledge, only paper and writing instruments for drawing garden plans and recording planting and harvesting details, rulers and tape measures for accurate garden area layout and area measurements, standard human-powered backyard gardening tools, kitchen scales, and a knowledge of basic mathematical operations and high school level geometry. (An abacus, for summing up weights, and a slide rule, for calculating weight per unit area, would be useful additions to this toolkit for those who prefer not to depend on the continued availability of calculators and the batteries they require.31) Carol Deppe has user-friendly information on how to do garden trials in her book Breed Your Own Vegetable Varieties.32

By communicating our results – through blogs, e-lists, local gardening and neighborhood associations, casual conversations, and the like – we would help ourselves and others to make the most of our gardening efforts and thereby reduce some of the negative effects of ongoing economic and environmental changes. Since doing a good garden trial requires a working knowledge of the scientific method and communicating the results to others helps the community of gardeners evolve better ways to garden faster than would otherwise happen, we would also get the scientific method into more hands and in a hands-on way that produces many benefits for those who apply it. This could result in more food security as we go through the Long Descent while increasing the odds that the scientific method will make it through the knowledge bottleneck that accompanies civilizational decline.33


Bibliography

Astyk, Sharon, Independence Days: A Guide to Sustainable Food Storage & Preservation (New Society, 2009).
Astyk, Sharon, and Aaron Newton, A Nation of Farmers: Defeating the Food Crisis on American Soil (New Society, 2009).
Clason, Clyde B., Delights of the Slide Rule (Crowell, 1964).
Deppe, Carol, Breed Your Own Vegetable Varieties: The Gardener’s and Farmer’s Guide to Plant Breeding and Seed Saving (Chelsea Green, 2000).
Duhon, David, One Circle: How to Grow a Complete Diet in Less than 1000 Square Feet (Ecology Action, 1985).
Ecology Action, Designing a Grow Biointensive Sustainable Mini-Farm: A Working Paper, Self-Teaching Mini-Series #31 (Ecology Action, 2003).
Greer, John Michael, The Long Descent: A User’s Guide to the End of the Industrial Age (New Society, 2008).
Hawker, Jon L., Missouri Landscapes: A Tour Through Time (Missouri Department of Natural Resources, 1992).
Jeavons, John, How to Grow More Vegetables Than You Ever Thought Possible on Less Land Than You Can Imagine, 8th edition (Ten Speed Press, 2012).
Solomon, Steve, Gardening When It Counts: Growing Food in Hard Times (New Society, 2005).
Solomon, Steve, with Erica Reinheimer, The Intelligent Gardener: Growing Nutrient-Dense Food (New Society, 2013).

Notes

1. Astyk and Newton 2009, pp. 58-59.
2. Astyk and Newton 2009, p. 69.
3. Letter dated 1/18/2009 from C. R. Lawn of Fedco Seeds, http://www.fedcoseeds.com/, and included with vegetable seed orders. At that time the growth rate in sales relative to the previous year was 42.5%. While the letters from subsequent years indicate that growth slowed relative to 2009, it appears to have continued.
4. The USDA’s Cooperative Extension System Offices website is http://www.csrees.usda.gov/Extension/index.html. The different state extension offices can be located through it. Missouri’s Extension website is http://extension.missouri.edu/index.aspx
5. Duhon 1985, pp. 191-196.
6. Astyk and Newton 2009, p. 28.
7. Endnote 9 in Jeavons 2012 regarding the possible yields column in the charts states “Estimates based on our experience and research. Use lowest figure if you are a beginning gardener,; middle if a good one; highest if an excellent gardener with exceptional soil and climate. (The testing and development process requires a long time and has involved many failures. … There is still much left to be done.)” It is from the mid-range yield given in an earlier version of the master charts that Duhon derives his assumed yields for his garden plans.
8. Crop yields are dependent on a number of factors such as growing season length, day length, severity of winter and of summer, soil type, rainfall, differential performance of crop varieties, and so on that vary widely across the U.S. There is no guarantee that yields obtained in northern California will be obtained in other regions of the country.
9. Jeavons 2012, pp. 33-43.
10. Ecology Action, 2003.
11. Astyk and Newton 2009, pp. 58-62. The 100 million new farmers figure is on p. 61.
12. Greer 2008. His discussion of the vulnerability of the scientific method to the effects of the Long Descent is on pp. 182-187.
13. Hawker 1992, p. 146.
14. According to the custom soil resource report for this location obtained from the National Cooperative Soil Survey’s on-line request service.
15. I obtained the broadfork from Johnny’s Selected Seeds, www.Johnnyseeds.com.
17. Chapter 3 of Jeavons 2012 addresses the functions of compost in the method and how to produce properly cured compost to maintain garden fertility.
18. Chapter 6 of Jeavons 2012 addresses companion planting and crop rotations.
20. Download the free PDF from the website in note 18 for the row feet to plant per person per year.
21. The formula and the rationale behind it are given in Solomon 2005.
22. Solomon 2013.
25. Jeavons 2012.
26. Duhon 1985, p. 194.
27. Astyk 2009, p. 102.
28. Jeavons 2012, pp. 39-43.
29. Jeavons 2012, p. 40.
31. Use your favorite search engine to find retail sources for both of these. Slide rules were still being used as late as the early 1970s, thus local yard and estate sales are a potential source of excellent slide rules at low cost. Clason 1964 explains how to use slide rules.
32. Deppe 2000, pp. 54-64.
33. Greer 2008.
 

2 comments:

  1. Fantastic job. I live the Houston, TX. area (zone 8b) and will be moving to southern MO in the next 6-8 years so I really appreciate the effort.

    Thanks for all the hard work.

    ReplyDelete
  2. Thank you for this informative post, it is helpful. Apparently us Texans are really interested in home gardening; as I, like the previous commenter, am from Houston area too.

    ReplyDelete