Soil is the very foundation of every garden and comes in different shapes, sizes, and consistencies. Getting a good grasp which soil is prevalent on your property is a good first step to start a garden. Here we’ll take a look at the 6 Main types of soil, what you can grow in them, how to improve/maintain them and which one is best for a veggie garden.
What are the common Types of Soil? There are a total of 7 soil types. The most prevalent soil types are Clay, Sand, and Silt. Peaty, Saline, and Chalky are rarer varieties. Loamy Soil is well-known and sought after by every gardener, being a well-balanced fertile option.
It’s important to keep in mind soil is, like everything in nature, not black-and-white. These Types only describe roughly how the soil of this kind normally behaves and common tendencies, sometimes nature can be weird though and that’s no difference here.
Now the question remains, what are the differences between these Soil-Types, what can I grow in them and how do I improve them? Let’s start by taking a closer look at Clay.
Clay soil consists of very small particles (>0.002mm) densely packed together, making it far heavier than the other Types. Clay can easily be distinguished by its consistency when damp it is sticky and can be molded into different shapes without cracking. Once the soil dries it will form a hard top layer, often cracking up in the process. I already did a more inclusive article on Clay Soil and how I did prepare my garden (I’d be happy to say my garden is clay-free – but it sadly that would be a lie)
Advantages: While clay can be very hard to work with it also has its advantages, no other Soil tends to be as nutrient-rich and water holding as Clay. Sadly Clay doesn’t offer much more besides this, except a good challenge.
Disadvantages: Lack of organic material within the soil causes it to drain very slowly, often leaving it waterlogged after rain. Its high water content combined with the very dense soil will only warm up very slow, is easy to compact and give your plants a hard time to establish roots. Working with Clay Soil is every gardener’s nightmare, this soil can only be properly worked when dry, but will still stick to all your tools, is very heavy and needs a lot of brought in materials to be useable.
What does grow in Clay: It’s hard to grow anything in compacted Clay, so soil improvement will be necessary for any garden being plagued from heavy clay. That being said, during the first couple seasons you can still try to grow different vegetables, mostly with shallow root systems, to take advantage of the water holding ability of clay. Here is a list of vegetables to grow in Clay Soil:
- Leafy greens
- Brussels sprouts
- Summer squash
- Flowers: Aster, Monarda, Roses, Helenium, Daylily, Coneflower, Bee Balm
How to Improve Clay Soil:
Adding lots of organic material like Compost, Manure, Peat moss, and straw will be necessary to improve the drainage and structure of Clay soil.
Mulching/Cover Crops: Clay is notorious for its slow water absorption rate, one way to prevent water from running off is by adding a layer of Mulch. This will not only help to keep water longer in place, but also reduce compaction, and as a bonus will also help to prevent your boots from an extra layer of clay each time it’s a bit wet outside. Cover Crops fulfill a similar role and can be planted in winter, some examples are winter rye and wheat.
Adjust pH level: Clay soil tends to be on the alkaline side of the spectrum taking the time to make a pH test and adjusting the soil accordingly might help to improve production. Alternatively, look at the plants that are already growing in your garden, this can help to get a basic feeling for its pH level.
Raised Beds: Sometimes the soil is just to bad to put in the effort to improve it, raised Beds are a great way to work around really heavy clay soil.
Adding Gypsum: Gypsum (calcium sulfate) can also help to loosen up clay soil. It’s important to know that Gypsum is not a substitute for organic material, but can be used in addition to it.
Before adding Gypsum on a large scale take the time to test if your kind of clay is working with it. Simply choose a small testing area, add it and see if any improvements are visible.
The second of the 3 Main Types of Soils is Sand. Sandy soil can be described as the opposite of clay soil in almost all attributes. This soil can also easily be Identified by feeling,has a rough, gritty structure and doesn’t hold together.
Advantages: The main advantage of sand heavy soil is its ability to drain water fast, so your plants will not be waterlogged. Due to its large particles, this soil is also faster to warm up, has good airflow and is easy to work with.
Disadvantages: Sand particles are small rocks, formed by the weathering of rocks, like granite and quartz. These minerals do not have the ability to hold water or nutrients making it a very light and unfruitful.
What does grow in Sand: Lack of water and nutrients can be quite a challenge for most vegetables and fruits. It’s important to improve sandy soil, so you are able to grow a more diverse selection of plants, but especially root crops and drought-resistant plants can thrive in sandy soil.
- Collard greens
- Flowers: Lavender, Sedum, Phlox, Salvia, Gazani, Crape Myrtle, Blanket Flower
- Desert Plants: If you live in a hot climate, and have sandy soil growing desert plants, like cactus might be your best option.
How to Improve Sand Soil: To improve sandy soil focus on its weak points adding organic matter in the form of compost will increase its ability to remain moist as well as increase its nutrient density.
Mulching: covering the top layer of your soil will help to keep it moist; after some time Mulch will decompose adding nutrients and organic material to your soil as a bonus effect.
Watch the salt: Sandy soil close to the sea tend to have a problem with salt, it’s normally not a problem if you live inland.
Adjust pH level: Sandy soil tends to be on the acidic side of the spectrum taking the time to make a pH test and adjusting the soil accordingly might help to improve production.
Raised Beds: I normally would go ahead and try to improve the soil before trying raised beds, especially with sandy soil, except you live in a desert.
Silty Soil is lesser known, not as common as clay/sandy soil and part of the 3 fundamental Soil Types. Silt consists of particles between the size of clay and sand, making it smooth to touch with a soapy or plastic-like feeling when wet. It leaves behind a bit of residue when rubbed between your fingers. Silt is mostly found close to rivers, lakes and other water bodies, combining both properties of sand and clay.
Advantages: Silt takes the good properties of sand and clay and combines it into one. It’s well-drained, can retain moisture, fertile and relatively easy to work with. Silty soil is considered one of the best soils to have for gardening, so consider yourself lucky if you have a natural deposit in your backyard.
Disadvantages: There are not many downsides to Silty Soil, the only 2 things to keep in mind is its tendency to compact under pressure, make sure to use walking paths when walking over this soil. Secondly, it sometimes can get waterlogged, so be careful not to overwater, but you’ll find it’s not as easy to apply to much water to this soil compared to clay.
What does grow in Silt: Well, it won’t be hard to find something to grow in Silty soil, almost all plants growing in a temperate climate will enjoy this soil making it a pretty versatile.
How to Improve Silty Soil: There is not a lot you can improve about silt soil, consider adding some organic material to reduce compaction, help the soil to drain moisture, and to add some nutrients.
Peat is another very interesting but uncommon Type of soil. It’s can be present in wetland, moors, and bogs, consisting of partially decayed plants. Chance of having a pure Peat soil is pretty much zero, as they develop over thousands of years in anaerobic soils and are highly sought after. I’ll still share some facts about this soil if you are interested, otherwise, feel free to skip this section. Peat feels spongy, has a dark color, and tends to be acidic.
Peat is a great water absorbent and offers good airflow. This soil is also major storage of carbon, sadly the extraction and drying of peat cause Greenhouse gases to be released back into the atmosphere.
Pure Peat soil is steadily decreasing making it quite a rare sight, which should not be disturbed or used for gardening purposes, it’s best to stay clear from any Peat products. If you want to read more about this topic, please take a look, here.
What does grow in Peat: Sometimes Peat can be found in already dried out bogs, this soil can be amended with fertilizer and limestone otherwise this soil is very good to grow almost all kinds of vegetables, as long as you adjust the pH-levels.
Chalky soil is an alkane soil derived from limestone and chalk. This soil comes in a wide array of consistencies ranging from gravel-like to clay-like.
Advantages: There are not a lot of pluses to this soil, except it’s relatively easy to work with it you don’t have a lot of stones and it’s exceptional draining abilities.
Disadvantages: Well-drained soil is good, but this also means you need to water it regularly. Not everything grows in Alkaline soil, and without some improvement measures Chalky soil is often not fully usable. Plants in this soil can struggle to get minerals like Iron and Magnesium, causing poor growth.
What does grow in Chalky Soil: Here is a very good list naming a lot of options to grow in this soil, however, if you have poor chalky soil don’t expect anything to grow in it.
How to Improve Chalky Soil: Adding Fertilizer, organic matter and building up the soil are all important steps to take when improving Chalky soil. Here is a more inclusive guide on how to improve this soil.
There it is the gold standard of soil, and every gardener’s dream: Loamy Soil. To get this soil a lot of work has to be put into your garden, or you win the garden lottery. Whichever way you came to have this soil, consider yourself very lucky, you have the most versatile and easy to handle soil there is, the only thing you have to worry about is to keep it this way. This soil can also be identified by feel, it’ll hold its shape after being compressed, but crumbles very easily under pressure.
Advantages: Everything, having pure loamy soil will give you the best growing conditions possible, grow to your heart’s content!
Disadvantages: The only thing to watch out for is erosion, loamy soil does not compact and can be swept away from heavy rainfall. It’s best to have physical barriers around your loamy growing bed.
What does grow in Loamy soil: Almost anything
How to Improve Loamy Soil: Keep adding some compost or fertilizer, this will help to maintain a high-quality soil. Otherwise, there is not much you can do to improve this soil, except for adjusting it to individual plants and keeping it the way it is.
Saline Soils are less of a Soil Type but rather describe the salt level within the soil. Saline soil is so salty they actually negatively affect plant growth. This Soil can easily be identified by its white salt layer covering the surface of the ground.
Advantages: You don’t need to salt you vegetables anymore (totally serious)
Disadvantages: Nothing will grow in this soil without a lot of work and some real dedication.
What does grow in Saline Soil: This mostly depends on the Concentration of Salt within the Soil, here is a nice List which compiles plants depending on the Concentration.
How to Improve Saline Soil: Treatment of this soil is normally done with a combination of flushing (using clean water to remove salt) and regular improvements once the salt is washed out of the soil. The second step depends mostly on the Type of soil present.
How to identify your soil
Mason Jar Test: Another way to Identify Soil-Types is with the Mason Jar Test:
- Simply use a clear jar with a tight lid
- Fill up half of the jar with soil from different places of your garden
- Fill the rest with water (leaving a small space on top for shaking)
- Now shake for a Minute
- Let the soil settle for the next couple hours
- After the soil is settled just measure how much sand(bottom layer), slit(middle Layer) and clay (top Layer) is in your soil, with this information and the Graph below you can figure out your soil Type
Which is the best soil for a garden? Loamy Soil provides the best of all soil-types in one. Well-drained, nutrient-rich, good airflow/water drainage, fast to warm up in spring and in almost all other aspects perfect. This good-for-all Soil is the product of years of hard work and the best for your garden.