Whether your garden is in-ground, in a raised bed, or in a container, garden soil is the most important ingredient to its success. However, creating the right garden soil doesn’t come easy.
It takes time and research to perfect it. This post will teach you first what exactly makes up good garden soil. You will learn what nutrients and elements need to be present.
From testing your current garden soil to learning how and what to add to it to improve its composition, it’s all here. By following the suggestions here, you will have enough knowledge to start the most successful garden on your homestead.
So grab a drink, find a cozy spot and enjoy the knowledge you are about to gain.
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Understanding the Types of Soil
There are 2 extremes of the texture of garden soil. These are sandy soils and clay soils.
If the sand particles are coarse, it is considered gravel. It will crumble when we touch it. Clay soils are smoother and when wet, it sticks together and smears like paint.
When sand and clay mix together they form what we call loam. Sandy loam allows the surplus water to drain through completely and clay loam will hold the water. The ideal soil should have equal parts of air and of water.
Understanding Organic Materials in the Soil
Organic matter is simply animal and vegetable matter undergoing the process of decomposition. It provides small amounts of the chemicals required by plants for growth.
It also adds humus to the soil. Lastly, it provides food for the soil bacteria, which, in turn, releases those chemicals in the soil that are otherwise unavailable to the plants.
What is Humus?
Humus allows the garden soil to be open and porous. That allows air and water to penetrate deep within the soil. It does this by acting like millions of tiny sponges that hold the water and some chemical food elements.
In other words, it allows the roots to take up these nutrients that they need.
Humus also allows surplus water to pass down to lower levels of the soil. Humusy soil warms up quickly in the springtime. This makes it possible to plant a bit earlier.
What Plants Need In the Soil for Growth
Plants firstly need oxygen, carbon, and hydrogen. They get these through the air and water. Next, they need 3 chief nutrients: nitrogen, phosphorus, and potassium. These are usually added through fertilizers.
Other elements needed are Calcium, magnesium, iron, and sulfur. Most soils contain these in sufficient quantities.
The so-called trace elements needed by plants for growth are manganese, boron, copper, zinc, and molybdenum. These seldom need to be added because it is such a minute quantity that is needed.
All of the above elements must be present in the garden soil as well as air, and water, and they must be insoluble form.
Complete Fertilizers
The 3 elements in all “complete” fertilizers are nitrogen, phosphorus, and potassium. By law, the percentage of each must be marked on the package.
The label may look like 5-10-10. This means 5% nitrogen, 10% phosphorus, and 10% potassium. If boron is included there will be a fourth number.
Just a quick fact if you are wondering where each of those elements is derived from:
- Nitrogen: sodium nitrate, tankage, or blood and bone (slaughterhouse by-products)
- Phosphorus: processed phosphate rock
- Potassium: potassium chloride or wood ashes (potash)
If you want to add natural ingredients to your gardens, read my post on 10 Natural Ingredients to Boost Your Garden.
Acid and Alkaline Soil
Garden soil may be acid, sweet (alkaline), or neutral. Most plants will thrive in soil that is neutral to slightly or moderately acidic. There are some plants that demand an acidic soil, and still, fewer that demand a really sweet or alkaline soil.
Soil acidity or alkalinity is measured by the pH scale. This is similar to a thermometer with 1 representing maximum acidity and 7 as a neutral point.
The Subsoil and Its Importance
The subsoil is the soil beneath the surface layer. This layer can be a few inches down or up to 20 inches plus in other places.
It usually has had to alter in hundreds of years of gaining humus and nutrients that have leached down over the years by rainfall.
Subsoils may be sandy or gravelly. This means that plants only get the nutrients from the topsoil layer only.
Some subsoils may also be a clay type. Sometimes these clay type subsoils are the causes of flooding because the water can’t penetrate this layer.
Clay vs. Sandy subsoils
Clay soils are often impossible to work with and may require a drainage system. That’s another post on its own.
Sandy subsoil, however, can be amended by adding the following:
- Manure
- Peat moss
- Organic matter
It can also be amended by planting the following green manure crops:
- Rye
- Ryegrass
- Oats
- Clover
- Vetch
Now that you have a basic understanding of soil types and components, let’s look at how to improve the soil you do have.
How To Improve Your Garden Soil
The first step in improving your garden soil is to decide if you have sandy or clay soil. A simple improvement is to add the opposite of what you have. If clay, add some sand. If sand, add clay. A one or two-inch layer of either type is a great start.
Adding Manures
A heavy application of a mix of horse and cow manure, two to three inches thick is the quickest method of improving the soil and adding plant foods. Make sure the manure is partially rotted.
Chicken and sheep manure are very strong and must be mixed with compost, dried leaves or other roughage to start decaying first.
If manure is difficult for you to get, peat moss and green manures will be the way to go. Peat moss is immediately effective furnishing humus in its ideal form.
Green Manures
Green manures have an advantage because they are much less expensive. It is just the cost of the seed and maybe some fertilizer to get them started.
However, they require a few months, up to a year, from the time they are planted until they are plowed in the soil.
Rye, ryegrass, and winter vetch are planted in the fall for winter growth and turned over in the spring. Other green manures mentioned above are also good for providing nitrogen to the soil.
Building a Compost Pile
Your basic compost pile can be built in the following order:
- Dead stalks and stems of corn, zinnias, and marigolds on the bottom
- Grass cuttings. Dead leaves, vegetable wastes, rotting fruits, peels 6” deep
- Garden soil 3” deep
- Peat moss 3-6” inches deep
- Lime in very limited amounts
- Manure (if available)
- Complete fertilizer
Beginning with the second layer, repeat this sequence until the heap is 4 to 6 feet high. The heap should be built with sides sloping gently inward and the top left with the saucer-like depression to hold water. When completed, enough water is given to saturate all materials in the heap without leaching.
If you are needing a complete guide to have and maintaining a compost pile you can check out; The Ultimate Guide To Composting. It has a lot of detailed information on starting a great compost pile.
For more detailed information on the many items that you can and cannot add to the compost pile beyond what is listed here, check out the ebook; Can I Compost That? by Oakhill Homestead.
Location and Size of the Compost Pile
The compost pile should be in part shade, where water is available. It should be screened from flower gardens and outdoor entertaining areas.
Ideally, the compost pile should be 3’x3’x3′ for convenience. You can dig down before starting the pile if you so choose.
The entire heap may be turned inside out with a spading fork at the end of one and a half months to hasten decomposition. Repeat a month later. In 3 to 6 months after that, the compost should be ready to use.
Taking a Soil Test
The last thing you do before planting your garden should be to take a soil test. This test should be done every 2 to 5 years. The result of the soil test will determine what should be added to the soil to make it fertile enough for your growth.
Take a soil sample in the following manner:
- Use a non-ferrous trowel or a stainless steel spoon to dig a vertical soil slice from the 0-6 inch level below the surface.
- Take samples from 6 to 8 representative areas and mix them together well in a plastic bucket.
Requirements and Guidelines of Soil Testing
Make sure you do not incorporate roots or surface organic litter into the soil being tested. Also do not sample for 30 days after adding fertilizers, manure, or compost to the area. The samples should be taken just before or right after the growing season.
You will need a total soil volume of 1 pound for professional testing and 4 heaping tablespoons for a home soil test kit. The soil samples can be taken to your local agricultural agent to be tested.
How about some Freebies!
Use the free downloadable fertilization chart to determine a good fertilization schedule for your garden after receiving a professional soil test. Click the link below.
If using a home test, can use the free “soil test” chart. Click the download link below.
Other Soil Modifiers You Should Know
Dolomitic Lime:
A great source of calcium and magnesium to be used when both are needed. Lime on the compost pile, if excessive can cause a loss in nitrogen. 1 qt. = about 3 lb. 8 oz.
If you notice flies you can add a layer of soil. This soil will also discourage flies.
High Calcium Lime (Calcite):
This is a good source of calcium when magnesium levels are too high for applying dolomitic lime. Oyster shell flour lime is a good substitute. 1 qt. = about 30 oz.
Gypsum (Calcium Sulfate):
This is used to exchange excess levels of exchangeable sodium. Apply only on the recommendation of a professional soil test. 1 qt. = about 1lb. 4 oz.
Crushed Eggshells:
These are high in calcium. Eggshells are especially good for cabbage family crops. Eggshells also help break up clay and release nutrients tied up in alkaline soils. Use up to 2 lbs. (1 ¼ qt.)/ 100 sq.ft.
Manure (all types):
Manure is a great source of organic matter in the garden. As a general rule, do not use more than 6 5-gallon buckets (4 cubic feet) of aged manure per year.
Another Freebie!
Download the quick reference chart below so you can make sense of how different types of manures are broken down before adding them to your garden!
What A Soil Test Will Not Tell You
Although a professional test will tell you deficiencies, excesses, and the relative balance of most all the plant nutrients, a home test is limited to pH level and deficiencies of nitrogen, phosphorus, and potassium.
Plants grown in soil lacking trace elements will show in yellow leaves, stunted growth, purple veins, or other ways. Seeds may not germinate for many reasons.
Common Causes of Seeds Not Germinating
- Planting too early or too late in the season.
- Use of weed killers and soil sterilizers
- Using old seeds
- Planting in soil that is too wet
- Use of Redwood compost. (contains growth inhibitors)
What’s Next?
Now that you have learned the types of soil, what elements and nutrients make up the soil, how to perform a soil test, and what to add to correct the soil, you are ready to start your gardening project. You should be well on your way to a very successful and fertile garden of any type whether it be vegetables, culinary herbs, medicinal herbs, or flowers.