Whether you’re a novice gardener or you’ve been at this for a while, you’ve probably noticed that life begins at soil level. All those seeds we coax into abundant, food-giving plants need healthy, well-balanced soil. Otherwise, life just won’t happen.
There are, of course, many different aspects when it comes to soil health. Although many people take it for granted, since “dirt” is everywhere and weeds survive in the saddest soils, there’s a definite balance.
So what can we do to make our garden soil lush and ideal to support life?
Life Begins at Soil Level
I came across the “nitty-gritty” soil health phrase in one of my partner’s herbalism study guides and had a good chuckle about it.
Hopefully, the lovely people at the Chestnut School of Herbal Medicine won’t mind that I adapted it for this article’s title. It really does encompass the fact that soil is full of grit and other bits and bobs that life needs to thrive.
If the ground outside your door isn’t frozen solid, head out there and grab a handful of soil. Run it between your palms, through your fingers. See how it behaves, and consider what you see and feel as you do.
Does it clump together firmly as you roll it, or leave thick streaks across your hands? Or does it crumble apart and slip through your fingers? Do you see decomposing bits of insect carapaces or glittering chunks of silica? Is the soil itself pale grey, or rich, dark brown?
Soils can differ greatly from one part of your yard to another, let alone across different parts of the country.
The earth you dig up in the Scottish highlands will be significantly different than that found on a Devonshire farm. Similarly, a scoop of Texas pasture will be quite the opposite to a loamy handful of Oregon rainforest floor.
Healthy Soil = Healthy Everything
One of my landscape design mentors suggested that we treat the soil we grow in as we do a growing child.
That’s kind of a disturbing thought, considering the shovels and tools we use in the garden daily. But to be clear, he refers to the care we give it. How we feed it, make sure it’s watered well, isn’t eroding, and is generally evolving into the best soil it can be.
Although, as mentioned, soils differ in composition and content depending on where you’re located, there are some soil health constants no matter where you are.
If you want to grow food, your soil needs to be loose enough for roots to stretch. It should also be dense enough to hold together and not blow away at the slightest breeze and full of enough nutrients that crops can gobble them up as needed.
Sure, a tomato plant can take root in depleted, sandy soil, but that doesn’t mean it’ll grow well. Nor will it bear fruit.
Generally, an ideal soil for vegetable gardening will be made up of approximately 40% sand, 40% silt, and 15% clay. Yes, anyone with a basic knowledge of maths will notice that this adds up to 95%, rather than 100.
That remaining 5% consists of the water and loose pockets where oxygen can circulate.
Do some soil tests before you start any garden planning, so you know what you’re working with. That way, you can determine the soil’s health (or lack thereof) and what you’d need to do to prep it for food growing.
Organic Matter is Your Friend
In simplest terms, organic matter is the lifeblood of your soil. In contrast to the clay and sand, organic matter is all the nutrient-dense “stuff” that feeds your growing plants.
Remember how all those fertilizer options have N-P-K ratios listed on their labels? Those letters stand for nitrogen, phosphorus, and potassium, the three major building blocks for plant life.
In addition to these major (primary) nutrients, plants require other minerals to thrive, such as calcium (Ca), sulfur (S), magnesium (Mg), carbon (C), zinc (Zn), copper (Cu), iron (Fe), and manganese (Mn).
Soil that has been depleted by monoculture, erosion, or just constant sowing without amending lack these and won’t be able to support life.
Harkening back to that growing child comparison, think of how a kid’s growth and development would be stunted if they ate nothing but white bread, without any protein, greens, fruit, healthy fats, etc.
They’d be stunted and sickly, just like plants you’d try to grow in this kind of earth. And so, we add goodness back into the soil to improve its health.
There are a few different types of organic matter: living, dead, and very dead. [1]
In this instance, “living” refers to things like microbes, earthworms, beetles, mycorrhizae, plant roots.
“Dead” refers to plant and animal detritus that’s in the process of breaking down. Here, we’ll find bits and bobs from dead insects, and plant bits that are decomposing.
If you have a multi-heap compost area, that second heap is an ideal place to see this kind of decomposition at work.
In contrast, well-aged compost falls into the “very dead” category. This is the type of rich, crumbly, dark brown tilth that occurs after everything has broken down wonderfully.
The Ideal Mix For Healthy Soil in the Garden
The ideal soil for your garden will consist of 70% VERY dead organic matter, 15% dead matter, and 15% living matter.
This is absolutely vital for the couple of inches in the soil known as the “root zone”. Can you guess why it’s named that? Right, because that’s where the plant roots draw up the majority of the nutrients they need to thrive, and to produce healthy, delicious food.
For example, berries that have been grown in healthy soil contain three to seven times more protein than those grown in depleted soils. Furthermore, they’re also sweeter and tastier. [2]
Random note: the next time you hold a handful of rich, well-nourished, healthy soil, consider that within the palm of your hand, there are more living organisms than there are humans walking on the earth at that moment. Isn’t that brilliant? Okay, moving on…
One of the best ways to ensure that you have healthy organic matter to improve your soil health is to cultivate a vermicompost system. Yup, that means worms. Worm poop, to be precise. The castings (poop) that the worms create are so full of nutrients that they’re often referred to as “black gold”.
There are many different, super-easy ways to make your own worm bin, so you don’t need to shell out a lot of money to make this happen.
Some of my favorites have been made from old wooden nightstands I picked up for a dollar or two at garage sales. Then just do your research on how to maintain them, get yourself some red wigglers, and you’re good.
Note that organic matter is best added in springtime, before planting, or in the autumn. Adding it in spring will provide a boost to seeds and seedlings right when they’re planted.
If you amend in the fall, everything you work into the soil will decompose and disperse over the course of the winter. This way, you won’t have to do all that work in the spring instead.
Amend According to What You Want to Grow
Although soils all need to be nourished well, what you feed them will also be determined by what you’re planning to grow.
Let’s take a look at two plants that need different soil conditions in order to thrive: tomatoes and kale. Yes, they’re great together in a salad, but in a garden? Not so much.
Tomatoes do best in slightly acidic soil. Furthermore, these heavy feeders need high phosphorus and potassium levels for flower and fruit production. If they get too much nitrogen, they’ll bush up but they won’t produce much fruit.
In contrast, kale needs the opposite. Brassicas in general do better in neutral to slightly alkaline soil. They’re the ones that need more nitrogen for leafy green growth.
When you’re designing your garden, you know that you need to take sunshine, elevation, and similar aspects into account.
Once you’ve determined what you’re going to grow, and where, be sure to test the soil. This way, you can adjust the nutrients and soil composition accordingly.
If your soil is a little too alkaline, you can reduce the alkalinity by working in more organic matter. Well-aged manure and compost are great for this. Look for those high in ammonium nitrate or ammonium sulfate. Peat moss is also great for adding natural acidity.
In contrast, if you’re looking to reduce acidity in the soil, lime is an ideal option. Agricultural lime (calcium carbonate) and dolomite lime (calcium magnesium carbonate) are two common amendments for this.
Just do a soil test first. If your garden is already high in magnesium, you don’t want to add more.
Break it Up and Feed It
This may sound contradictory, but it’s an essential way to amend and nourish and create healthy soil.
As an example, we recently did a consultation with a gentleman in Arkansas who wants to transform an old horse pasture into vegetable gardens.
He’s got some clay-heavy soil that’s heavily compacted from years of hooves dancing over it. That soil is also extremely depleted from near-constant grazing.
Although plowing and tilling will help to break it up quickly, an ideal approach would be to sow successive cover crops on it for the next few years.
Comfrey and dandelions have deep taproots that reach deep into stubborn soil to break it up. Buckwheat, clover, and alfalfa can assist with shallow breaking, while depositing nitrogen and phosphorus. When that comfrey is mowed and used as green manure, it’ll add potassium as it breaks down.
You get the idea. Doing this successively for a few years would result in some pretty healthy soil. That’s especially true if your work in additional amendments regularly.
It’s kind of astonishing to see how different plants thrive (or fail), depending on the soil they’re in. If you have kids, consider doing an experiment in which you get them to plant the same kind of seeds in different types of soil: some depleted, some well-nourished.
Seeing firsthand how healthy soil affects growing plants can drive home the idea of how and why eating healthy foods affects our own bodies.
Heck, you might even get them to eat more broccoli as a result. One can only hope.
Feed your soil well, and it will feed you and your family in turn. In Braiding Sweetgrass by Robin Wall Kimmerer, the author talks about how we turn to nature countless times a day and say “feed me.” And it does. [3]
As such, it’s important that we reciprocate that generosity and offer it nutrition and care when we can.
It’s all about balance and respect.
When In Doubt, Talk to the Locals
If there are farmers or avid gardeners in your area, see if you can book some of their time for a consultation to chat about soil health.
This doesn’t have to happen on your property (or theirs) but can take place over a cup of tea or even via online chat. They’re likely ideal resources for helpful information unique to your area.
For example, if you’ve been having difficulties soil health, growing crops, or dealing with particularly stubborn herbivore predators, these locals may have solutions that you wouldn’t have considered on your own.
There’s a wealth of information available from our elders if we take the time to listen to them and heed their advice.
This could save you a lot of frustration trying to sort out issues you’re having with your garden. Just make sure to compensate them for their time in a manner that works well for them, whether it’s monetary or with a few jars of something lovely from your home pantry.
References:
- Fred Magdoff and H. van Es, Building Soils for Better Crops (1st ed. Lincoln: University of Nebraska Press, 2000)
- D. Jacke and E. Toensmeier, Edible Forest Gardens, Volume 1 (Vermont: Chelsea Green Publishing, 2005)
- R.W. Kimmerer, Braiding Sweetgrass (Minneapolis, Minnesota: Milkweed Editions, 2013)
