Techniques for Maximizing Small-Scale Growing Spaces
Happy Friday! This taste of spring weather has been such a refreshing and uplifting treat. There is still some snow on the ground here in the low points of the property but most of our beds are completely uncovered now. Today, as I inspected the beds, I found that even though we had some really bitter cold in January and February there are a few survivors that were growing under the snow without any season extension materials: summer crisp lettuce ‘Muir’, self-seeded radishes, celery ‘Ventura’, scabiosa ‘Black Knight’, and snapdragon ‘Madame Butterfly Bronze’. Even though we have another burst of cold on the way, the jobs around the farm are feeling more and more like spring chores. After I write this quick blurb I’ll be heading out to the woods to collect some leaf mold from the forest floor. I’ll ferment some leaf mold tea and then combine it with some water-soluble calcium (made from our hen’s eggshells) as a bed amendment; this mix will be full of mycorrhizal life that will wake those beds up and work to reduce compaction. The dahlia tubers have been taken out of storage to get an early start in nursery pots. This weekend will be spent seeding main season flowers, peppers, and eggplants as well as presprouting anemones and ranunculus. In the next week or two I’ll be adding a few inches of compost to each bed. And finally, I’ve already begun harvesting flowering branches for wreathmaking and will have the first flowers of the season in about three weeks. This winter has felt endless but it will come to an end soon enough.
Even though we are two months away from our last spring frost date, we’ll be transplanting the first round of crops outside on April 3rd and anticipate that we will have a nice selection of vegetables by mid-May including radishes, broccoli, tatsoi, rhubarb, green garlic, and lots of different herbs. With planting time so soon, I thought this would be a great time to share some information about the various ways we maximize our tiny 4,000-square-foot market garden and offer some tips for home gardeners who’d like to make the most of their small spaces, too.
Permanent Standardized Beds
When I was growing up, my parents had a large and productive garden but it was very much done in the conventional growing pattern of tilling as soon as the garden could be worked, growing crops in single rows with two or three feet between each row, and finishing the season by tilling again in the fall (though, thankfully, they didn’t spray at all). It was a lot of work each year. In order to till their heavy, sticky clay soil, they would need to wait until May most years in order to be able to get the tiller through the ground which meant that by the time the ground had rested and recovered after tillage nothing could be planted until nearly Memorial Day. The clay would get so hard, cracked, and clumpy at the surface that it would hurt my feet whenever I walked around the garden barefoot. The cycle of tilling would bring weed seeds up to the top of the soil and weed pressure was not just a major hassle but practically a part-time job to manage. Don’t get me wrong… My parents grew the absolute tastiest tomatoes and I think that my romantic early memory of wandering around the tomato rows in my bathing suit with a salt shaker in hand is probably a big reason I found my way back to pursuing a career in market gardening.
If you look at a traditional garden like my parents’ from a bird’s eye view, what you’ll see is a whole lot of wasted space. This is exactly why the standard for market farms is 30-inch-wide beds with 12-inch-wide walking paths between. These standardized beds make it easy to plan crop rotations from year to year and to know exactly how many plants we can squeeze into a given amount of space. By keeping our foot traffic to the designated pathways we also eliminate compaction in the beds. A home gardener might consider doing something like 24-inch beds with more generous 24-inch walking paths between (or to use wood-framed beds) and get a similar effect. Furthermore, permanent no-till beds eliminate the need to wait until it is dry enough to use a tiller. That’s why I’m able to plant so early in the season with very little effort.
Forego the Seed Packet Spacing
Returning to my childhood garden, tomatoes were typically spaced three feet apart within each row with nothing planted between them. Heads of lettuce were one foot apart within each row. And so on for all of the other crops. In a small space, this is wasted real estate. Within a standardized bed, planting in a grid formation maximizes the amount of things we can grow within a given space. Taking it one step further, by reducing the space between each plant, while yield per individual plant will be slightly less than if we followed the generous numbers listed on the seed packet, we will get a significantly higher overall yield per bed. It also creates a canopy effect, much like in a full-canopy forest, which shades the soil and therefore aids with water retention and prevents weed growth. (On a separate but related note, I also utilize heavy-duty landscape fabric and plant into holes that I’ve burned into it at perfect spacing, which even further helps with these things but additionally warms the soil in the early and late parts of the season and offers a small buffer for the cold.) By planting into offset rows at 6” apart, for example, I can fit 38 heads of lettuce in a four-foot section of one of my rows. Sold at a price of two for $5, this is a significantly better use of the soil - and my time - than if I had just done a single row in the same length based on the seed packet. In the case of single-stem sunflowers at the same 6” spacing, this intensive spacing actually makes for a more moderately-sized flower that is much more suitable for floral design work, and at $2 per stem it turns out to be a rather lucrative crop for the small-scale grower. For those of us in a somewhat moist climate, we must also consider the risk of problems like powdery mildew and bacterial growth, so it can take a bit of trial and error to figure out just how closely you can plant things together without sacrificing quality.
Succession planting is crucial to ensuring that I can have a prolonged harvest of various crops over the course of the season. When crop planning, I categorize vegetables as high rotation or long field time. The high rotation crops are the ones that mature relatively quickly, take up bed space for just a small chunk of the season, and have a relatively short harvest window. I consider them high rotation because as soon as they are finished and harvested I can quickly replant that bed space with another high rotation crop (and then repeat for a total of three or sometimes four rotations throughout the season). The long field time crops are exactly what they sound like; they’re the things like parsnips and pumpkins and tomatoes that stay in the ground throughout the entirety of the frost-free season (mid-May to early October here) and take a long time to reach their harvest stage. I aim to have a constant supply of those high rotation fast-maturing vegetable seedlings that I can just pop in wherever I end up with a space, and for many things that grow well in the field for seven to eight months of the year without additional protection - lettuce, beets, carrots, tatsoi, and scallions to name just a few - this means that I plant a new batch of them every two weeks starting in February and continuing through July. Conveniently, many of these high rotation crops are also some of the ones with the highest revenue per bed.
I love peer-reviewed research. Personal anecdotes are great, but in the off-season I really enjoy digging into the literature to find answers to my questions and to brainstorm solutions to any problems I’ve encountered. Intercropping, also known as the practice of growing two or more crops in the same bed, is a lovely example of this. If you do a Google search for companion planting or intercropping you might find some cute infographics with “good” and “bad” pairs with no further references, or you may come across the phrase “if it goes together [in cooking] it grows together”.
But for a more concrete and evidence-based solution geared towards those growing for profit, I spent some time earlier this winter looking for answers to how intercropping affected (1) yield per plant, (2) yield per bed, and (3) revenue per bed. In one particularly interesting study (Güvenç & Yildirim, 2005), the researchers experimented with pairing eggplant - a slow-growing vegetable with a long field time but relatively low value - with various types of lettuce and found that there was no change in the yield per eggplant plant when intercropped with the greens. However, there was a significant increase in the revenue per bed. Here is why that works: pairing something that takes up field space for a long time, such as eggplant, with things that have a short field time and a high value, such as lettuce, means that we can cash in on multiple plantings of the lettuce before and during the eggplant harvest time. Another example might look like pairing a crop that takes up field space for a long time with a shorter harvest window like watermelon or winter squash with something that will provide an ongoing and prolonged harvest such as branching sunflowers (a simplified and modified Three Sisters set up). For hardy annual flowers, Bare Mountain Farm in Oregon recommends pairing trellised sweet peas with single-harvest stock underneath. But in relation to the study on eggplant, I can assume that I may be able to swap out other vegetables with a similar growth culture and achieve similar results - perhaps pairing tomatoes with chard, peppers with cilantro, or tomatillos with beets.
It’s also largely said that intercropping can reduce weed and pest pressure, and this is supported by the research as well. Hendges, Melo, Guimaraes, & Rabelo (2018) found culinary herbs to be particularly helpful in reducing aphid populations on kale, noting that cilantro and parsley were the most effective. Lowering the aphid populations increased the fresh weight production as well. In this case, I can also transfer the research to planning intercrops in the brassica family, such as pairing broccoli with chervil or cabbage with parsley or collard greens with shiso. The yield and revenue of the main brassica crop won’t be negatively affected and I’ll get a second crop and revenue stream from the culinary herbs.
Like intercropping, relay cropping simply refers to planting a new crop into an existing crop before you harvest it. While I haven’t tried it yet, this year I plan to relay plant summer squash into a bed of bok choy, tatsoi, and kohlrabi that will be harvested 1-2 weeks after the squash has been transplanted. I plan to do the same with tomatoes, peppers, tomatillos, eggplants, and cucumbers into the first and second succession plantings of other various high rotation crops that will be removed within 1-2 weeks. Since I can’t plant the squash, tomatoes, etc. until mid to late May, I’ll still be able to utilize that space and grow crops there starting in early April.
Choosing Cultivars Based on Days to Maturity
If you want food and you want it fast, I recommend finding crops that have 60 days to maturity or less. If you have the space to do so, starting some crops that are traditionally direct seeded indoors can reduce the days to maturity by 7-14 days. Examples of this are squash, cucumbers, kohlrabi, snap peas, radishes, and sunflowers. This also gives you more control of the germination environment, reducing the risk of things like critter damage or rot due to overly cold and/or moist soil.
Planting in Clusters (“Multisowing”)
Popularized by no-dig master Charles Dowding at his picture-perfect farm in England, multisowing is a simple way to grow more things in less space. Basically, instead of planting one seed per block, you would plant multiple. As you harvest the biggest plant in each clump, you’ll open up more resources for the others to grow as well - sort of like thinning your crops at the last stage of growth instead of right after they germinate. Last year I grew half of my radishes, chard, herbs, and onions the traditional single-seeded way and half in multisown soil blocks, and when I tell you that the multisown ones were better I really mean it. The radishes particularly amazed me as they were the longest, most beautiful French Breakfasts I’d ever grown. When your indoor seed starting space is a limited commodity like at our farm, this is really a wonderful thing to try out. Crops that I’ve grown successfully in clusters include culinary herbs, arugula, beets, chard, onions, scallions, radishes, and spinach. This year I’ll also be experimenting with growing baby fennel, summer leeks, turnips, Persian cress, bachelor buttons, and nigella this way.
If it’s possible, growing something with a long field time on a trellis allows you to space the plants closer together, get a higher quality product (cleaner fruit, straighter cucumbers, uniform stems), and offers more airflow to reduce risk of powdery mildew and bacterial growth. Pruning crops like cucumbers and indeterminate tomatoes to a single vine trained along a string with all of the bottom leaves removed opens lots of space to plant more quick-maturing high rotation crops.
Season Extension Materials
For those who want to get serious about extending the season, there are a few structural things that can be done at a relatively low cost. Utilizing Agribon fabric for the first two weeks of the early season plantings can keep them safe from frost and maintain a temperature slightly above the ambient outside temperature. It can also be used over newly seeded carrots to retain moisture and prevent seeds from being dried up or washed away. Alternatively, for more substantial warming and greater extension in early spring or late fall, low hoops made of 9-gauge wire or metal conduit and covered in 6mil plastic such as Tufflite can do the trick. Coldframes on the south side of your home can be used year-round to grow cold hardy greens. We look forward to expanding to the new five-acre property so we can finally have room for proper high tunnels (unheated greenhouses) to grow both food and flowers throughout the winter months.
Most of these crops must be planted before midsummer so that they reach maturity before the last ten-hour day (early November for us). Under cover with hoop support, though they won’t continue to grow, crops like oxheart carrots, salsify, parsnips, winter leeks, scallions, claytonia, kale, spinach, arugula, and winter lettuces will maintain their quality well.They can be harvested as needed throughout the winter and will resume growth after the following first ten-hour day (early Feburary).