Square Foot Gardening High-Value Veggies

by Mel Bartholomew

  So, for purposes of the listings and calculations in Section 2, we used the most common varieties that represent the closest possible approximation to what you would find in a grocery produce department.

  We then surveyed a range of grocery stores and farmer’s markets to determine what the average carrot weighs, or how many Brussels sprouts are in a pound on average. This way, we had a common number for the price per pound, which would relate to the pounds-per-square-foot yield (you didn’t think I’d get all the way through this without bringing up “Square Foot” did you?). We then determined the actual yield for a given crop over a standard season by checking academic studies and the yield estimates of seed companies, where available.

  SOME FINE PRINT

  One issue that came up in researching the yield weight over a season of different crops involved unit-for-sale versus edible portion. Some agricultural academics go to great lengths to filter down any crop’s yield to the “edible portion,” the amount leftover when inedible and unusable parts are discarded. This was too problematic to consider for our purposes. Yes, fresh corn produces fewer cups of edible kernels than hulled strawberries do. But both are sold whole at retail. So we used that whole portion as the consistent baseline. For the same reason, we measured and considered only loose produce, not prepackaged. Bags of potatoes or plastic clamshells of trimmed baby lettuce leaves may be widely available at retail, but there are too many variables in those processed products to make for a fair comparison in our calculations.

  That said, if you want to drill down in our calculations, and you’re adamant about measuring only edible portions of your garden crops, you can create a “weighting factor”—a numerical range of numbers to be subtracted from the yield number based on the portion of any crop that is composted as waste. Seems like a lot of work for very little reward as far as I’m concerned, but I would never stop anybody from working with numbers. This would, however, change the relative position of some crops on the list such as corn and broccoli. But it wouldn’t radically affect our Top 10.

  Gardeners grow their gardens in lots of different ways. Some grow traditional rows, others grow in containers or raised beds, and those who have read my other books grow hyper-efficient gardens in boxes, square foot by square foot. Fortunately, the production of any of these can be conveniently converted into yield per square foot. As the founder of Square Foot Gardening, I already had access to well-established data on what most edible plants produce in an actual square foot. That gave us a “foot” up in getting the numbers in the formula right.

  That Pesky Price Per Pound

  Establishing the price for pound we’d use in each case involved even more thought and investigation. Ultimately, we turned to the United States Department of Agriculture’s (USDA) Agricultural Marketing Service. The service provides a bi-monthly “National Retail Report” for common fruits and vegetables sold at large retail outlets—namely supermarkets and large clubs such as Costco. The report provides, among other things, a national cost-per-pound average for a wide range of fruits and vegetables. The average is determined from a survey of prices in supermarket ads across the country. Although this is only a snapshot, it is comprehensive and countrywide. We felt it was the best, most reliable source for baseline pricing information.

  Who doesn’t love to shop at a farmers’ market? Although the prices aren’t always cheaper, many of us find great value in buying fresh produce direct from local growers.

  We used the report for mid-July. Due to seasonality, several edibles on our master list were not included in the report. So in those instances where we needed a national average, echoing the method that the USDA uses, we did our own survey of supermarkets in different regions. These samplings included random supermarkets in the north, south, east, and west of the country.

  Supermarkets Versus Farmers’ Markets

  But why supermarkets? Given the difference between the standardized and often processed nature of supermarket produce and what comes out of most backyard gardens, there was an argument to be made for using produce prices from farmers’ markets. Unfortunately, we not only could not find a reliable comprehensive database on farmers’ market prices comparable to the USDA’s National Retail Report, the sampling size would have been a whole lot smaller. The Farmers Market Directory available on the website of the industry group Farmers Market Coalition lists 8,100 registered markets in the 2013 directory. For that same year, the Food Marketing Institute listed over 37,000 supermarkets with $2 million or more in annual sales. That’s almost a five-fold difference.

  Supermarket produce could come from practically anywhere and it is often grown to withstand shipping long distances.

  The differences in costs are going to be much greater among farmer’s markets region to region, given the localized nature of farmers’ costs and related expenses. For instance, the organizations that run local farmers’ markets often charge fees. On the other hand, large supermarket chains often buy one type of produce from a single major farm supplier. The price of that item will vary little from store to store in the chain. The same is not true from farmers’ market to farmers’ market. Those variations are one more reason why we choose supermarkets for pricing information.

  GROWING VALUE: THE DIFFERENCE BEYOND DOLLARS

  Even though the produce available in your local farmers’ market may be pricier than what you find in the local supermarket, when it comes to assessing price-per-pound of any produce, you have to make sure that what you’re comparing is, well, truly comparable. Studies from industry organizations, such as the Northeast Organic Farming Association’s Vermont’s Pricing Study, have found that on a pure calorie quality-to-price comparison, farmers’ market produce is actually on par with the prices you’d find in supermarket.

  There are other, less tangible benefits as well. A survey in Farmers Markets Today revealed that more than 85 percent of the produce in local farmers’ markets traveled less than 50 miles to get to the market. Many farmers markets require that the produce sold be grown “locally,” within a predetermined range (often as little as 10 miles from the market—they could walk it to market!). Obviously, the transport distance, and time from field to shelf, is far greater with supermarkets. That means more fuel burned and produce that ripens in transit rather than on the plant. Given that studies have long shown that nutritional value in produce degrades over time, the price on that lug of tomatoes or a few ears of corn is only one—and perhaps not the best in every case—indicator of high value.

  There are even more esoteric concerns that may appeal to one person or another on a personal level. Farmers’ markets help support small family farms and are usually a way to keep money within a local community. The point is, garden investment is—to one degree or another—in the eye of the beholder.

  Accounting for Diversity

  One of the biggest challenges in researching the price-per-pound category is making direct comparisons to individual classes of vegetables without considering the differences variety to variety. There is a limited amount of diversity in supermarket produce because the crops are chosen for qualities like durability and resistance to the stress of shipping. All that produce must also look uniform and capture what the average shopper has come to expect a potato, tomato, or head of Romaine lettuce is supposed to look like. Supermarkets are trying to give their customers what they want, not just what’s available.

  If you visit a farmers’ market, you’ll see greater diversity. Small farmers can afford to grow different varieties, including those less sensitive to the strains of transportation and corporate production. For instance, you’re far more likely to find heirloom tomatoes in many sizes, colors, and textures (including what the average consumer might think is too soft) at a market or co-op than anything you would find in a supermarket.

  We’ve attempted to account for the many variations among any given crop (i.e., we’ve included four different tomatoes in the calculations). As much as possible, distinct differences between w
idely available varieties are also dealt with in the text under each listing. This will be give you some direction in selecting, for example, the types of carrots or tomatoes you plant, and should help you balance that fine line between what you’re most interested in growing, and which varieties or types will deliver the biggest return on investment.

  Some rare exceptions exist. If you live in a state that doesn’t grow a highly perishable crop, importing that crop could be expensive and will be reflected in your local costs. That will be something to consider when you’re judging crops against each other and consulting the listings.

  The part that may really amaze you is what the numbers work out to be. For instance, you might not think of plain old basil as a cash crop, but it turns out that the price per pound can run higher than $16. I’ve seen a lot of jaws drop when I tell gardeners that fact. But the math doesn’t lie. Most basil offered at retail is sold in small plastic packages of two or three stems with mature leaves. The weight is often less than an ounce—and can cost $3 or $4! Imagine enough of that basil to make a pound. Then consider what a single, healthy, thriving basil plant will produce over a season. Suddenly, the big number makes sense.

  A tomato is not a tomato is not a tomato. We couldn’t possibly treat each of the thousands of tomato varieties grown individually, so as with some other veggies we broke tomatoes down into categories for purposes of comparison: heirloom, hybrid, cherry, and Roma (determinate). You’ll have to read on to find out which of the types has the best return on investment. (HINT: Sometimes big things come in little packages.)

  The “Real” Price Per Pound

  Ultimately, the important thing to note is that we’ve used the same pricing rationale for all the price-per-pound numbers in the listings. This gives you a starting point. You can refine the calculations to reflect your own garden’s value based on whether you’re growing produce that is closer to what you’ll find in the local farmer’s market, or more mainstream varieties that resembles what’s on offer at the local supermarket. In most cases, the reality lies in the middle ground between those two prices.

  LOCATION AND PRICE

  The reason we used national average prices per pound for the listings in the vegetable calculations was because prices can vary significantly from one region of the country to another. This is more a consequence of shipping than of individual state economies.

  Regionality will also affect the number of farmers’ markets and co-ops in a given area. If you’re lucky enough to have an abundance of these types of farm-to-table outlets, you may want to substitute the average prices we’ve used for the prices that are closer to what you’ll find locally.

  In any case, keep in mind that the variables we’ve included are flexible; adjust the figures as you see fit to reflect local conditions.

  What a Difference a Year Makes

  Nobody controls the weather, which is why there is no way to account for severe weather events in static calculations like those used in Section 2. As hurricanes, droughts, and other severe weather events become commonplace, agricultural production can vary wildly from one year to next. Changes in the weather may change the value outlook of whatever you decide to grow.

  GARDEN CROP PRODUCTION COSTS

  Water is an inescapable expense for just about every garden, and it’s getting more costly all the time. You can limit water usage by practicing smart watering techniques: for plain efficiency, nothing is better than pouring water slowly right at the base of each plant so you’re not watering any weeds or bare soil.

  Many different variables go into growing a garden, involving a variety of expenses. The costs associated with gardening can be divided into two groups—what we’ll call fixed costs, and ongoing expenses that you’ll deal with in each growing season.

  Generally, if you buy a quality garden trowel, it will last for a very long time and the cost will be amortized over the years, so that expense actually impacts your garden’s overall financial picture very little. Something like water or seeds is an ongoing expense that is incurred each season. Ongoing costs have the biggest impact on your garden expenses and how much return on investment you realize from what you grow. Ongoing costs also rise over time.

  Because both types of garden expenses change radically based on myriad factors—from the size of your garden, to what you grow, to the gardening method you’re using—adding these expenses into the formula we used for our calculations didn’t make sense. But that’s not to say you should ignore them.

  INVESTING IN GARDENING TOOLS

  The number and type of tools you need to grow edibles depends a lot on the gardening method you choose. One of the great advantages of Square Foot Gardening is that you only need four tools: a trowel, a bucket, a pair of scissors (I like the cheap kids’ style), and a pencil.

  The best bargain in gardening tools is not always the cheapest option available. In a bottom-line sense, the best investment you can make is the tool that lasts the longest relative to its original cost. Here are some tool fine points that you should consider the next time you’re shopping in the garden center:

  • Comfort

  • Durable materials

  • Quality construction

  No matter what tools you buy, you’ll get the most value out of them by taking care of your tools during and after the season. Sharpen bladed tools prior to working with them to make the work easier and the tool last longer. Properly store hand tools on a peg rack or other unit that keeps them organized and off the garage or shed floor. At the end of the season, clean and store your gardening hand tools in a dry space that doesn’t experience freezing temperatures or excessive condensation.

  In looking at your own expenses and what you grow, you may want to keep track of significant costs. You can then choose to calculate them against the projected ROI from our listings for the crops you’ve grown. There’s another reason to track costs as well: there are a number of strategies you can use to reduce those costs once you identify them.

  Gardening Tools

  Basic gardening requires few tools, and most of those implements are inexpensive. At the minimum you’ll need a trowel and gardening gloves (for Square Foot Gardening and most container gardening). You may also need a garden spade, fork, cultivator, and hoe for more traditional gardening approaches. The reality is that these tools will usually last more than a decade with a minimum of care, and can easily be purchased used or on sale. Ultimately, if you spread the cost out over years of gardening, tool expenses will have little impact on the overall value of what you grow.

  Equipment Issues

  Garden value can also be affected by any equipment you’ll need for the crops you raise, although this will generally be a much smaller expense than tools. You’ll use your judgment as to whether to associate equipment cost with a single crop—and add it to the “input” amount for that crop in your calculations—or spread the cost of equipment across several or all of your crops.

  Usually this is a fairly clear-cut issue. Cages or trellises for your tomato plants should be an expense added to the input costs for your tomatoes (after being divided by the number of years of life you expect to get out of the cage or trellis). The cost of something like lumber for raised beds should be divided evenly across all the crops grown in that bed (again, divided by the number of years you expect the wood to last).

  But some expenses will be hard to calculate into any given crop. A new garden hose, for example, might be used for both your garden plants and a portion of your landscaping. A container bought for a container garden may be used for other plants in the future and could feasibly last so long as to represent a miniscule expense when the purchase price is divided over years of use. As far as I’m concerned, when in doubt, leave it out of the calculations.

  The best part of taking a bottom-line approach to everything you buy for the garden is that you quickly see how expenses can add up. I think a big part of high-value gardening—one that is easily overlooked—is cutting down on these incid
ental equipment expenses. The best way to do that is to find items to reuse and recycle in place of garden equipment. An existing cyclone fence can be a trellis. And if you’re looking to build raised beds, you can often find free lumber from construction sites. (Just be sure and always ask before taking anything from a work site, and never use treated wood or any that has been painted.)

  Adding Amendments

  You’ll quickly notice in reviewing the calculations that we’ve left out any numbers for the cost of fertilizer, compost, plant food, bone meal, and other amendments. Frankly there’s little that is constant among amendments. Depending on the makeup of your soil (how rich it is, how well it drains, etc.) you may need far fewer amendments than a person in the next town over. You may, in fact, need none. If you’re growing in a Square Foot Garden, you don’t need to add anything once you’ve created the ideal growing medium I call “Mel’s Mix.” It’s equal parts peat moss, vermiculite, and blended compost. You can also limit your input expense by choosing to grow vegetables and varieties known for their hardiness and ability to make do with fewer nutrients and water than other plants.