If you’re looking for the best way to prepare soil for vegetable garden then you need to read this post…
We’ll explain what plants need to thrive and how you can improve your soil overtime.
“Each soil has had its own history. Like a river, a mountain, a forest, or any natural thing, its present condition is due to the influences of many things and events of the past.”Charles Kellogg
There are several popular gardening methods that focus on improving and nurturing soil and it’s for good reason.
It’s important to understand that soil is not just dirt that anchors pur plants in the ground. It is a non-renewable resource and a complex ecosystem that needs to be protected.
“Thanks to conventional farming practices, nearly half of the most productive soil has disappeared in the world in the last 150 years, threatening crop yields and contributing to nutrient pollution, dead zones and erosion.
This is concerning because it’s predicted that continuing at this rate of distruction would give us just 60 years before we run out of useable top soil!
The soil is not just ‘dirt’ to anchor plant and tree roots, though that’s how many people treat it! The soil is a very complex ecosystem, teeming with very diverse life.
As gardeners we can learn so much simply by observing nature.
Take a walk in a woodland and notice how rich and springy the ground is. Lush plants thrive without a hose pipe or bottle of chemical fertilizer in sight.
You’ll notice dead wood and fallen leaves carpet the forest floor and underneath that you’ll find a rich, moist, dark compost that’s speckled with white mycelium.
I’m not a fungus expert but I understand enough to know that those tiny specks of white are a sign of great soil!
Mycelium helps the soil by breaking down all that organic matter which keeps the moisture in, adds nutrients and prevents erosion.
To demonstrate just how full of life our soil is…there are about 50 billion microbes in just 1 tablespoon of soil. The human population on earth is currently aroubd 7.8 billion!
Great soil will be home to other living things too, like earthworms.
One hectare of land can support up to 7 million worms, which all collectively weigh 2.4 tonnes, and in favourable conditions they can turn over around 50 tonnes of soil per hectare each year, enough to form a new layer of topsoil 5 mm deep!Deep Green Permaculture
It’s pretty amazing really!
The trouble is that tilling or digging the soil actually damages this amazing setup that nature has developed…unless of course you follow permaculture and no-dig methods of gardening.
Much like in the forest a healthy vegetable garden soil is one that is rich in humus from decaying materials. We can replicate this in our gardens and raised beds by adding organic matter like leaves, grass clippings and compost.
We want soil that is light and not compacted so it is full of the air that roots need to ‘breathe’. It needs to drain well but hold moisture and it needs living organisms like earthworms and fungi to love living there!
Plants need around 16 specific nutrients to thrive.
Three of these nutrients come from the air (carbon, oxygen, and hydrogen). The others need to come from the soil or fertilizers.
Nitrogen, Phosphorus and Potassium are the most important nutrients that a plant needs to get from the soil. Some gardeners use “complete” fertilizers that add these three nutrients back to the soil.
However, chemical fertilizers have a detrimental affect on the environment and don’t include other nutrients that plants need to thrive like magnesium and calcium.
The best way to improve soil quality and ensure the presence of essential nutrients and organisms is to focus on organic, permaculture methods that will ensure long-term soil health.
Another important aspect of good growing soil is its pH reading. A soil with a pH number below 7 is acidic, while one above 7 is more alkaline.
Most plants grow best in neutral or slightly acidic soil (around pH6 to 7) but some plants like blueberries prefer more acidic soil and a few like, asparagus will do better in soil that is neutral to slightly alkaline.
The vast majority of plants however won’t thrive in a soil that is highly acid or highly alkaline. In general, a high pH prevents nutrients be absorbed efficiently but a low pH causes the plant to absorb them too quickly which overloads the plant.
If you’re unsure what type of soil you have, you can buy an inexpensive test kit to find out.
It is possible to adjust the pH of your soil overtime. For example, adding compost, manure or sawdust to soil will in time lower the PH of alkaline soil.
However, if you have concerns about soil pH it may be easier to grow native plants or build a raised bed. (Take a look at these great ideas for filling raised beds cheaply).
In addition to finding our your soil’s pH, and ensuring it has good macronutrient and mineral content you’ll want to look at its texture.
Soil texture affects your plants growth for a few reasons.
Soil with a good texture will:
• allow air to circulate which means that plants can access nitrogen and organisms can access the oxygen they need to thrive.
• let in just the right amount of air to allow organic matter to decompose.
• allow roots to take hold easily so they can grow strong.
Soil is made up of varying amounts of sand, silt, clay, rocks and organic matter. The amounts of each will effect its texture and how much air it contains. It’s all about balance…
Sandy soil will feel gritty to touch as the sand particles are relatively large and far apart. The right amount of sand helps with soil structure and provides air and water pockets where plant roots get a good start in life.
Too much sand however will mean that the soil holds too much air which causes organic matter to break down too quickly making it low in nutrients.
Silty soil feels quite slippery when it’s wet but is like a fine powder when it is dry. It holds little air because its particles are tightly packed which means that plant roots can’t access the nitrogen they need and organisms can’t thrive with low oxygen levels.
Clay is the gardeners friend because it holds moisture, binds fertilizer and helps to release it slowly. However, for all of its benefits, if your soil is made up of lots of clay it will clump together and block out air.
A perfect mixture of clay, sand and silt is called ‘loam‘.
Loam is the perfect soil type for growers because it’s fluffy, easy to work with and nutrient rich. Loam will roll into a ball easily but it doesn’t keep its shape like a clay soil would.
The trouble is, that many people don’t have access to perfect soil.
The good news is that there are ways to ensure good growing soil whether you’re in a new build with a garden full of rubble or an apartment with no soil at all.
This can be done by:
My soil is hard and dry
Growing in compacted soil
My soil is too wet
My soil is like clay
My soil is too acidic
My soil is too alkaline
I hope we’ve helped you to decide on the best way to prepare soil for a vegetable garden. Remember to take a look at our other helpful posts.