Moving from growing a simple garden to planting a sustainable garden that provides most of your food intake for the year takes a little bit of work. If you jump onboard with popular gardening techniques then you immediately are dumping a pile of cash into the garden, and while that is doable, it also wastes resources and money, and it impacts the return on your yield. Nobody really sets out to grow $13 per pound tomatoes, but if you invest in all the boxes, soil, amendments, and gadgets you can easily pay $13 a pound for your tomatoes. Not only is that cost prohibitive it is not sustainable, especially in an emergency. This article begins a conversation about sustainable gardening and the business side of growing your own food. Specifically, we talk about soil health and how that relates to sustainable gardening.
A View of Commercial Farming and the Spill-over into Small Gardening
Many commercial farms use inputs to strength the “growability” of soil on the farm. These are often nitrogen, potassium, and phosphorus. Inputs may also include pesticides and herbicides too. In short, the farmer is paying for additives that help him keep his fields active throughout the growing season. The cost of those inputs is offset because of the size of the yield that a commercial farm produces. In the home garden, we have available many similar products from fertilizers to drip irrigation and fancy tools that we probably don’t really need.
In comparison to smaller yields for the home garden, the cost of using inputs reduces the ROI for having a garden. Right now, and granted it is just spring, the local price of tomatoes on the vine from a national grocery store is $3.39 a pound. A single tomato plant can produce 15-25 pounds of tomatoes – varieties such as early girls, etc. – At the supermarket price you would pay $67.80 for 20 pounds of tomatoes. That price is really your break-even mark for growing a tomato plant. So what do you need to grow a tomato plant?
- A 15-gallon container – $6.64 plus tax and shipping
- Soil – $8 or more for organic
- Water – unsubstantial cost on the smaller scale
- A plant or seeds – $3.99 for a four pack of tomatoes or $2.75 for a packet of seeds
- A trellis – though technically you can let them sprawl – Wide range of prices and options – $3.75 plus shipping for a basic tomato cage.
- Fertilizer – E. B. Stone tomato fertilizer is about $9.99 depending on where you buy it.
- Netting – potentially – $14.00
- Pest control products – maybe – About $10 for a small bottle of Neems oil
The total start-up costs come to $56.37 with the netting and pest control which are optional. The prices will vary by location and whether you buy in season or on the offseason, online or locally. The savings, however, for 20 pounds of homegrown tomatoes over the store-bought tomatoes is a mere $11.43. Not only is there an investment in getting started – many of these products are reusable season over season, but there also is an issue about sustainability as your food supply is still dependent upon outside factors that may or may not be available when you need them. The goal of this illustration is to help to drive home the point of this article – home gardening does not need to be expensive and if managed correctly, can be fully sustainable.
Soil Health – The gateway to positive yields
Soil does a few things and when it cannot accomplish those things its ability to grow plants diminishes. The “things” that soil should do are:
- Retain water for plants
- Provide nutrients for plants
- Provide a structure for plant roots
There is also a natural cycle within the soil that dictates how well any given plot of land will be able to sustain plant life. That cycle is complex, but in short, it is the recycling of nutrients through both the humus and topsoil layers of soil.
The layers of soil are broken down into tiers. The top layer being the humus layer which is characterized as a layer of organic matter. The humus layer is where last year’s crop residue would be found, or all the fall leaves. On the forest floor, we call this “duff.” It can be thick or thin depending on its geographic location and environmental conditions. The layer beneath the humus layer is called topsoil. It is within these two layers that we look to determine soil health. The cycle is something like this:
Plant matter accumulates on the surface forming the humus layer. Rain and weather begin to breakdown the “humus” and small organisms – insects, fungi, bacteria, etc., – assist in breaking down the plant matter into smaller forms of nutrients – nitrogen, phosphorus, minerals, etc. Rainwater percolates through the humus layer and topsoil layers and carries the nutrients deeper into the ground – root zone – of the plants. Other organisms eat the soil – or the smaller bits of plant matter – earthworms add to the soil by shedding and digesting the soil. Small bacteria consume the soil and fix nitrogen into a usable form for plants. Larger creatures such as beetles, moles, voles, etc., tunnel through the soil helping to add oxygen and prevent anaerobic conditions. The cycle repeats when fall comes and new material is added to the humus layer. A compost pile could arguably be called a humus pile, and it serves as a very vivid example of the process that occurs naturally in fallow land.
These little steps all work together to help transform the humus layer into topsoil. Healthy soil is full of nutrients that plants can use, full of life – biota – that benefit the plant and the soil. It is rich, aerated, and due to the higher levels of organic matter, it holds water without being overly moist. All these characteristics create an environment that helps plants to thrive.
What Does this Mean for Home Gardening?
Understanding soil health and caring for the soil in your stead is one of the most important things you can do as you begin or continue to grow your own food. Rich, nutrient soil is possible and when you achieve that you drop the cost of all those soil additives and the payoff is seen in more abundant crop yields.
Even in commercial agriculture farmers are beginning to turn away from conventional methods of farming and going back to practices that support soil health – tilling vs. no-tilling. With conventional farming, there is no humus layer, and as the crops leech nutrients from the soil, the farmer must replace those vitals with man-made chemicals. There are issues such as soil subsidence, erosion by wind and water, and there are physical changes to the soil layers, such as the formation of hardpan via the compression of topsoil and subsoil layers.
Something similar happens in the home garden. We build beds or use containers, but the plants eat up all the nutrients and then we must add amendments or replace the soil- either of which drives up the cost of producing food. Potting soil, for example, is not great at holding in moisture so that means we must water more often, especially in hotter areas. Amendments in container gardening are a must, especially for the first year as there is little if any life in the soil. It takes some time for earthworms and other soil biotas to make their way into a container garden. There are a few tricks that speed up that process which I will discuss farther along in the blog.
Maintaining Good Soil Health
There are many ways to increase the health level of the soil around your stead. One of the things that I focus on here is recycling. Much of what remains of a crop goes into the compost pile. Old tomato plants, pumpkin plants, corn stalks, etc. I also have 16 hens, and they make plenty of “amendments.” They also get a nice bedding of straw which goes into the compost pile. I use cover crops for plots and beds that are not in use. Fava beans are an excellent plant because they give you both a harvest and are colonized by beneficial bacteria at the root level for nitrogen fixing.
A cover crop helps bacteria to fix nitrogen in the soil. The air is primarily nitrogen, but in that form, it is not very usable to plants. The nitrogen in the soil must also be converted into a usable form for plants, and that is one of the jobs that beneficial soil bacteria do. It is easier to think of soil as a living organism. A short list of plants that are great as cover crops are:
- Peas – anything that is a legume. Sugar peas, sweet peas, snow peas, alfalfa, even clover, though clover can quickly become a weed issue. This includes beans, such as fava bean.
There are schools of thought that also indicate that certain grasses make good cover crops and they can but no in terms of improving soil nutrient levels. The use of grasses as a cover crop has more to do with maintain loose, loamy soil and addresses soil constitution and structure rather than nutrients. Grasses do not help with the nitrogen-fixing cycle. You would plant grasses in places where the ground has a lot of clay in it and where you are trying to break up clay and add organic material to the soil.
When soil dries out the soil biota leave or die and their ability to help maintain good soil health diminishes. The role of the humus layer is also to help reduce evaporation of water from the topsoil layer. Cover crops also help to keep soil moisture level higher. In the home garden, you can use mulch to help keep weeds down and soil moisture levels up.
What Happens When You Have Bad Soil?
If your soil is poor, all is not lost. The correction process just takes time and resources, but if you start small, you can control the costs and improve the land. Even if you are doing container gardens, you can enhance and control soil health. These tips help to build soil quality and aid in improving soil health.
Generally, I mulch in the fall, which works well for my zone 7B gardens. My preferred mulch is fallen leaves mixed in a ration of 3:1 of leaf material and chicken manure. I also supplement with straw. If you buy it at the peak of summer, straw is cheap. One tip for generating mulch material is to plant hedgerows. The property here is ten acres, and I have fruit trees spaced out along the property line on two sides. Lots of apple trees and crabapples, persimmons, pears, etc. All of these drop their leaves in the fall, and I go along and rake them up for mulch. Not only am I growing my own mulch, but I also get a bunch of fruit too. We also have a lot of oak trees and walnut trees around, and their leaves can make good mulch but keep in mind both have a lot of tannins in them. I use the acidic leaves to mulch plants that like acidic soils, such as blueberries.
The trick to good compost is to keep the pile aerated and moist. To do this, make layers – dry, wet, dry, wet. Dry compost material can be leaves, grass clippings, cardboard, straw, etc. Moist layers are made up of food scraps, coffee grounds, fruit, such as squash that is not usable. Healthy compost does not stink. It should smell mildly sweet and earthy, but not like a sewer. If you have that rotten egg smell, then the pile has gone anaerobic and needs to be turned with layers of dry material added into it. People get all crazy about compost. Don’t make it complicated. You don’t even need a container. You can make excellent compost just making a pile in the corner of the yard. A good tip for an inexpensive compost bin is to scrounge up three wooden pallets and tie them together to make a three-sided box. You can also use hog wire and t-posts. If you use a container for composting, make sure that you can open it up wide so that you can turn the pile without fighting with the container.
3. Grow Cover crops
Put the soil biota to work for you. When I build a new garden bed, I fill ½ of the container with raw compost – The stuff in the top or middle of the pile. I cover that with a layer of straw and then add soil to the top. Give it a proper watering and let it rest for a few months. What will happen is that the biota in the compost will continue to break down the soil while the straw begins to decay. If you water your box enough to keep it slightly damp, the worms and insects in the composts will move to the surface, and the entire process will “sink,” and you can then top off the box with more soil. Turn the soil with a spade and sow a cover crop onto it if needed. TIP: I generally put in new garden beds in the fall and let them be until the growing season starts. Many cover crops, such as snow peas or fava beans can tolerate some cold, but not hard freezes. You can also cover the box. Also, the rawer the compost, the more heat it will generate, and that can be enough to keep cold-hardy plants alive during a hard freeze.
4. Use Compost Teas
For new containers and garden beds, I use compost teas. I use a 5-gallon bucket with three ¼ inch holes drilled into the bottom. Fill the bucket ¼ of the way full of fresh compost and then fill the bucket with water. Because there are holes in the bottom of the bucket, I do all of this in the spot where I want the tea to drain. You can use smaller containers, such as a milk carton with the same ratio. 1:3 compost to water. Compost tea is an excellent tool for inoculating new containers with beneficial bacteria. You will also transfer some of the nutrients from the compost to the soil in the container.
These are the four primary tricks that I use to keep the soil in my garden healthy and ready for production. I still have to buy some supplements, especially for tomatoes which need calcium and other minerals. At the feed store, you can find bags of oyster shells, and I add those to the beds where I grow tomatoes. I don’t do a whole lot of crop rotation, but I do focus on growing crops that complement each other. By this I mean, I plant snow peas where I grow tomatoes or fava beans.
A note about plant types
Not all plants want to grow in the best of soils, which by the way, is subjective. Some plants, like blueberries, love acidic soils while plants like collards grow best in rich loamy soil. While we are talking about soil health, it is also important to understand that the tools and tips in this article are also the basis for managing soil types. You will need to adjust the soil pH for some crops, but for healthy soil, you will still need to use many of these tools.
The goals are to improve soil biota – the life in the soil, improve the capabilities of soil to retain water, improve soil nutrients, and to improve or maintain positive soil structure – a loose humus layer with a nutrient-rich topsoil layer. When we learn to manage soil health, crop yields rise, and we improve one of our most important natural resources. Good soil can be a sustainable asset, but we have to be willing to learn the tricks and be willing to do the work.
David Stillwell is a lifelong naturalist with a background in healthcare and biology who lives in the heart of wildfire territory in Northern California. Prepping for him is a way of life and necessary on a daily basis. He focuses on food production and agriculture and grows 80% of what he consumes.