Thank you for visiting Edwin Binney’s Community Garden Blog. We have been growing and distributing fresh produce in the City of Kawartha Lakes since 2019 with the help of many volunteers and partner organizations. To date we have donated 56,093lbs of fresh produce.
In this short series of blogs, we’d like to share our gardening tips and tricks to help you grow your own food, increase the biodiversity of the local environment and discuss how growing food locally helps our communities. In this first blog we will explore the foundation of the garden; Soil.
The Foundation of Life: What is soil, testing your soil, and improving the soil
What is soil?
We may walk over it many times each day not giving it much more than a mere glance. However, the ground or soil we trod upon deserves so much more than that. At a macro level soil looks like a mixture of various sized particles from sand up to large rocks. But look a little closer, now we see that there are also clumps of a dark brown material that holds moisture and gives off the scent characteristic of earth. These clumps are the decaying organic matter of previously growing plants such as leaves from trees or lawn clippings. On its own this organic matter would stay preserved, unchanged from when it fell from a tree or when we cut the grass. As we are looking closely at the soil, we now notice that there are in fact living organisms; worms, ants, beetles, pill bugs and much more. If we had a microscope, we would be able to see even more organisms living in the soil. These organisms are responsible for helping the fallen organic matter turn into soil by breaking it up, eating and digesting it. In addition, these organisms also eat and digest each other keeping the balance of helpful and harmful organisms in check. All this activity helps to release the stored nutrients in the decaying plant material making it available for small animals, microbes and future plants to feed on.
In essence, the soil that we walk on each day, played in as kids (or adults) and shape into our personal landscapes is much more than a collection of various sized particles. It is a living breathing community that contains more living organisms in a tablespoon than there are people on Earth (Hoorman & Islam, 2010). Soil is a community that works together to clean up, recycle and repurpose previously growing organic matter in order to support the continued growth of future organisms.
Though there is not a universally agreed upon definition of soil we have defined it for the purposes of our discussion here as; a complex and diverse community including macro and microscopic organisms, various sizes of rock particles and decaying organic matter that support life cycles above and below its surface.
How do we know if our soil is good to start a garden?
Though our soils at home and even at EBCGs may be able to support the growth of grasses and some perennial flowers, bushes or trees we may have difficulty growing plants for food as these plants typically need slightly different conditions than what is already growing in the area. You could of course just turn over a section of your lawn and plant edible plants or their seeds into this soil but getting a decent harvest would have similar results to throwing darts with your eyes closed and hoping to hit a bullseye.
To help you understand the structure of your soil, its ability to hold or drain water, and its potential ability to support the growth of your crops, tests should be completed prior to planting. These tests can range from simply looking at and feeling the soil to collecting a sample of soil and shipping it to a company to perform a complex analysis. And of course, these tests range in cost from free to hundreds of dollars, so keep a budget in mind as growing for yourself or neighbors likely won’t require very expensive and complicated tests.
Simple tests can be completed with items and materials that you likely have at home already. The first involves simply digging up a sample of soil in an area where you would like to grow some plants. Evaluate the consistency of the soil. Is it loose or hard? Does it feel fine and smooth or is it coarse/gritty? Describe the color of the soil. Is the soil dry, damp or wet? Does the soil have visible decaying organic matter and living organisms?
Soils that are loose usually have good drainage and allow plant roots to grow deep into the ground, increasing the root surface area enabling the plant to absorb more water and nutrients. Harder soils tend to hold water longer or create areas in the garden prone to flooding which can drown and rot our crops. Similarly, soils that are coarse or gritty contain more particles of sand which helps with improving drainage while soils that feel very fine/smooth or silky consist of silt and clay which have more surface area to hold onto moisture. Good soil should have a mix of these substances that allow it to hold enough moisture for plants to use but also drain fast enough to not drown the plants.
The color of the soil can also give you an idea of its composition. Clays typically are found in light brown, gray and red. Sands also come in shades of brown from light to dark. Organic matter usually appears as a very dark brown or black substance.
A slightly more complex test using a mason jar can give you a more accurate description of the composition of your soil. Using a hand trowel, dig up a sample of soil from the top 10 cm of your potential garden area. Place this sample in a mason jar, aim to fill the jar with 10 cm of soil. Fill the rest of the jar with water and place the lid on top. Shake the contents of the jar for one to two minutes then let the jar sit undisturbed for 24 hours. Over the course of 24 hours the soil particles will sort and settle themselves into layers on the bottom of the jar. From the bottom to the top of the sample the layers will consist of 1) sand, 2) silt, 3) clay and 4) organic matter. The substances that make up the soil (sand, silt, clay, organic matter) all have different densities meaning that after being shaken in the jar they fall through the water at different rates thus we see the sorting and layering effect. Now you can use a ruler to measure the thickness of each layer then divide that by the total thickness of the sample to calculate the percentage of each substance present.
These two simple tests can give us valuable information about our soil’s texture (percent of sand, silt, clay and O.M.) as well as whether it is currently able to support life. To grow edible crops though, it is helpful to know what elements are present and may be available to our plants. There are three elements that plants need in large quantities, you have likely seen these on fertilizer packaging as N-P-K, they are nitrogen, phosphorus and potassium. Plants also need other elements and minerals from the soil but in smaller amounts, we refer to these as trace elements/minerals. This is where testing the soil can get quite expensive. Many garden and hardware stores sell simple home chemical tests that can give you a vague idea of how much of the macro elements (N-P-K) your soil contains. These are fine for home use but are limited as they typically consist of a color changing chemical that you compare with a key provided with the kit that gives you a value range for the given nutrient. More expensive tests can be performed by universities and private labs, for a larger cost, with the equipment to analyze the samples and provide more detailed results in percentages. Another limitation of the home test kits is that they don’t test for the trace elements/minerals.
Finally, plants also grow in soils that have various pH levels. Most vegetables and fruits do just fine in neutral soils while others (like Blueberries) prefer soils that are slightly more acidic. A quick refresher on the pH scale. The scale is measured from 1 to 14, 7 is neutral while less than 7 is acidic. The pH scale is a logarithmic scale that measures the amount of hydrogen (H+) ions in a substance, in our case the soil. For every whole number decrease on the scale the acidity level is increased 10 times. So why do we want to know the pH level of our soil? Some plants like Blueberries mentioned above need higher concentrations of H+ in order to absorb nutrients from the soil. So, while our previous tests may indicate that our soil contains suitable levels of N-P-K, we may struggle to grow Blueberries if we don’t know the pH of the soil.
Testing the pH of our soil at home is fairly easy. Many of the kits that are available for testing the N-P-K values also come with a chemical test that will give a value range for the pH. Simply add a sample of soil to the provided test tube, add pH indicator provided, fill the test tube with water and shake. The solution will change color and you can use the key provided to identify the pH of your sample. Digital pH test units are also available at garden and hardware stores. To use these, you will need to mix a sample of soil with some water in a mason jar (we’ve already got that prepared from our earlier test!). Now take a sample of the water from the mason jar and place it into a separate container. Place the metal probe of the pH test unit into the sample solution and a digital value will be provided.
Improving the soil
Now that we have gotten personal with our soil and collected a bunch of data about its texture, fertility and chemical composition, how do we use this information to help us improve our soil for growing food?
Let’s look at soil drainage first. If growing in the ground, as opposed to in containers or raised beds, the most common issue you will face is slow drainage. This results in water logging of the soil which displaces oxygen and drowns the roots of the plants and causes rot. There are mechanical and (let’s say) “natural” ways of dealing with slow drainage and its cause.
Slow drainage is likely caused by soils that are high in clay or soil that has been compacted by foot traffic or heavy machines traveling on top. Whichever the case mechanical methods most often used in home gardens to improve this issue are tillage, digging with a spade, or broad forking. Tilling, though very common, is something we want to avoid. In the short term it does a wonderful job of mixing the sub-soil layers with the topsoil temporarily improving drainage. Over time continued tillage results in compaction of deeper layers of soil. There’s no need to be dogmatic with this rule, as a single tillage event to start a garden is unlikely to result in severe negative effects. The key is to limit its usage. Digging with a shovel or spade is similar, albeit a much slower version of tilling. It’s also very labor intensive if you are starting a sizable garden. A tool called a broad fork is often used in organic and no-till market gardening. Broad forks are used to penetrate, separate and slightly lift compacted soils to allow water, air, soil organisms and plant roots to migrate into the deeper layers of soil. Broad forking or forking with a pitchfork is the recommended mechanical method of alleviating soil compaction and drainage issues in our gardens.
“Natural” methods of coping with compacted soil take a little longer to work than mechanical methods, but also contribute to building a healthier and more diverse soil environment. If you live in an area that experiences true winter, water that has penetrated the soil through wormholes, broad fork holes, or root spaces will freeze and expand pushing chunks of soil apart and breaking up some compaction. Another “natural” method is to use cover crops. Cover crops are simply plants that we can grow in our gardens that we don’t intend on harvesting but help keep the soil covered and support biological life under the surface. Forage radish (also known as tillage radish or daikon radish) grows large and long tap roots that are very effective at breaking up compacted soil and can be included with a mix of other cover crops to compound this benefit with the benefits of others. More info on cover cropping will be included in an upcoming article.
From our soil fertility tests we now have an idea of how much nitrogen, potassium and phosphorus (the three most important plant nutrients in soil) are available for our crops. As with anything else in life we can make this process as simple or complex as we desire. If you are so inclined and have received detailed chemical analysis of your soil from a scientific lab you could calculate exactly how much of each nutrient you need to add based on your garden’s surface area. That’s too complicated for me as I would rather spend more time planting than solving the required math problems. Fertilizing in this method also runs the risk of over fertilizing which can lead to the excess chemicals being washed away with heavy rains polluting natural ecosystems. Look up algal blooms and fertilizer contamination for more information. Rather than using synthetic or refined organic fertilizers, slow-release organic fertilizers are available and are made with by-products of organically grown crops such as alfalfa, cottonseed meal, peanut meal, and soybean meal just to name a few. As the name suggests the fertilizers release their nutrients slowly, feeding the plants and microorganisms for a prolonged period. As suggested earlier cover crops are handy to use for improving soil and can be used beyond breaking up compacted soils. For example, plants in the legume family (beans, peas and clovers) create a symbiotic relationship with certain types of bacteria in soil. The bacteria can take nitrogen that has moved into the spaces between the soil particles and turn it into a form that is available for plants to absorb. In return for this nitrogen plants provide the bacteria with a home in their roots (nodules) and sugars that they have made through photosynthesis. Other plants that create very deep tap roots are also able to bring nutrients and minerals from deeper layers of soil and make them available to plants with shallow root systems. Our favorite plants that create deep tap roots are sunflowers and others in the aster family of plants. Cover cropping is a great method to increase soil fertility, organic matter and biodiversity of our gardens and more information will be provided in a future article, so stay tuned.
Another option of soil improvement that doesn’t necessarily fit in one category is the use of compost. Compost is a naturally occurring process that turns once living material into a nutrient rich substance and component of soil. Using compost in the garden can provide similar benefits to using slow-release fertilizers. In addition, compost creates a great environment for macro and microscopic soil organisms to live in. Worms, for example, eat the decaying organic matter and excrete nutrient rich waste. They also tunnel through the soil breaking up compaction and depositing some of the nutrients in deeper layers of soil.
Conclusion
Starting a garden to produce your own food can seem like a daunting endeavor but the satisfaction and reward of eating fresh fruit and vegetables from your own yard is extraordinary. By taking the time now before planting to inspect the soil you have will save you from tremendous headaches later in the season. If you haven’t already, consider starting a compost system to help you build your soil diversity and reduce the amount of waste going to landfill.
Thank you for taking the time to read our first article in this series. In the next article we will explore sourcing water for our gardens. In each article we will be exploring gardening topics in a sequential order to help you with each step throughout the entire growing season. Make sure to check back frequently as new articles will be posted each week.
References
Hoorman, J. J., & Islam, R. (2010, September 7). Understanding Soil Microbes and Nutrient Recycling. https://ohioline.osu.edu/factsheet/SAG-16
About the Author
E Kelly (they/them) is passionate about supporting the health of their community. While working closely with individuals in the health & fitness industry E noticed a concerning trend. Many individuals’ health concerns did not stem from a lack of knowledge, willingness or desire to eat healthier or exercise more. Instead, a growing number of health issues were correlated with a lack of access to healthy foods. Thus started E’s journey in learning more about sustainably produced foods and how to produce an abundance in small spaces.
With a formal education in Kinesiology and years of experience growing food as a hobby, E is combining their experience and knowledge base to promote the production of local and sustainable produce.
E is the Garden Coordinator at United Way of the City of Kawartha Lakes and Edwin Binney’s Community Garden located in Lindsay, ON.
