The Story of Soil
Lush vegetation, brightly colored floral arrangements, sweet and earthy scents adding a natural perfume to the whole affair. Yes, your garden can be quite the poetically beautiful place to spend a peaceful afternoon. But just what is it that makes your garden such a special spot? What is the one thing all your plants rely on to make this whole orchestra play together so beautifully? Is it you? Well, yes, without you there would be no garden! However, I’m referring to the humble, yet mighty soil that fills your various pots, planters, beds and other gardening apparatuses. If you’re anything like me, you generally buy the second cheapest potting or garden soil you can find at whatever store you go to (this is the same trick I use when looking at restaurant wine menus). Nonetheless I can’t help but wonder what the differences between the more and less expensive soils are. Does one really make your produce grow larger? Is that just because it has fertilizer mixed in, what if I just get my own fertilizer and add it in later? While I don’t exactly have an entire growing season to conduct such an experiment, I can do some thorough research! So, if you too are interested in the differences between various soil types and how they can help your gardening journey, this blog is for you!
To start, let’s list off the different types of soil you may come across. Clay, loam, sandy, peat, silt and lime rich/chalky type soils are the major types of gardening soil you may have in your yard/find for sale. Each has different properties that make them better suited for different types of gardening. Each type of soil can be found naturally in different regions around the world. Soil type can even change depending on what part of your state you’re in. The main differences among these soil types are the composition, ability to hold and provide nutrients, drainage and coarseness or feel.
Clay: Clay based soil is the heaviest type being it is mainly consisting of sedimentary rocks. They are generally porous and erode easily. Rich in nutrients, clay soils are great for growing fruits, veggies, flowers, basically the works! However, clay soils can compact overtime, making them less accessible for growing roots, leading to a decline in quality of plants overtime. If you are keen on starting a garden and using the same soil for a while, I wouldn’t recommend clay based soils.
Loam: Loam based soils are a mixture of sand, silt and clay. As with many things, there are varieties of loam soil, for example, sandy loam is a mixture that is heavy in sand and silt more than clay. Loam is generally speaking, going to be your best friend when gardening. Unless you are trying to grow something specific that does well in a specific soil type that isn’t loam, it should meet your gardening needs. It’s a more loose soil that allows roots to penetrate and can hold nutrients well. It also has the advantage of a texture that can hold water long enough for roots to access but still drain off enough not to flood your plants. You may not find loam type soil naturally, so you may need to add different components to your existing soil to achieve the consistency you want.
Sandy: Sandy soils are often found in desserts as well as near shore lines. Pretty much exact opposites in people’s minds, but really what is a dessert but a beach without an ocean? Sandy soils are best for growing things like succulents and other plants that don’t require a whole lot of water all that often. Sandy soils often have trouble with water. While it can often suck up a lot of water, it doesn’t drain particularly well.
Peat: Peat type soils generally come from decomposing organic matter. Things like dead plants and animals. This is particularly beneficial in terms of nutrients existing naturally in the soil. Peat can also hold onto a lot of water making it great for growing plants. However, like clay type soils, peat can compact over the years which can result in poor conditions for your plants.
Silt: Silt soils are often found in areas that experience water frequently. Erosion is really the reason for silt type soils as water erodes rocks into micro particles. Silt soils are often fertile in terms of nutrient retention and availability for your plants making it a great choice for plants that require a rich soil. However, silt type soils do rely on their proximity to water to grow plants successfully. They do not retain water very well so drought resistant plants are best, or if you want to use a lot of water on your garden. Silt type soils always make me think of the Nile delta and how ancient Egyptians had very specific growing seasons centered around when the Nile was running higher. Which now makes sense considering their farming land was made up of silt type soils.
Lime Rich/Chalky: This type of soil is largely composed of limestone and naturally occurring chalk. This is a very particular type of texture for soil, but it is very rich in nutrients and minerals beneficial to plants. Much like clay and peat soils, lime rich/chalky soils can lose their effectiveness overtime. Their ability to retain water becomes uneven and it begins to drain poorly over years of use.
As it seems, each soil is specifically suited for growing different types of plants. While this may be obvious in the natural world, cacti grow in the dessert etcetera, but it still does get complicated when you’re at the garden shop. So when you’re picking out your next bag of soil, think about what type of plants you’re using it for. I’m not saying go out and make sure you find a specific type of sandy soil the next time you buy a succulent, mine grow fine in generic potting soil. But if you are planning on creating a meticulously curated garden, make sure the soil type matches the plants.
If you are still a bit confused, rule of thumb is to go with slightly sandy soils for vegetable gardens, loamy type soils for most everything else. However, you are going to want to change out the soil from time to time. As previously stated, each soil type can lose its effectiveness over time. You will need to, at the very least, mix in at least a few new bags of gardening soil to any bed after a few years to ensure your plants are getting the nutrients they need. Try to stay consistent over time with what kind of soil you are using to ensure your production is relatively the same year after year. If you have a specific garden bed you were planting flowers but now wish to grow succulents, make sure you add in the necessary components to safeguard success.
If you are worried about soil compaction, there are a few ways you can avoid it. Avoid walking around in your garden too much. Heavy foot traffic can lead to compressing the air pockets inside your soil and overtime reduce its effectiveness for growing plants. Avoid working with your soils while they are overly wet. I’m not saying you can’t garden in a light sprinkle, but don’t try to rearrange your begonias during a thunder storm. Wet soil is heavier and so the more its thrown around in your garden while wet, the more it compacts the soil. You can also try adding mulch to your garden beds! Mulch is an excellent work around for a few different reasons. Firstly, mulch can alleviate some of the pressure of footsteps and other compressions in high traffic areas. Mulch is also a great way to help your soil retain moisture, the added layer on top of your soil will keep it from direct sunlight, thus impeding the evaporation process on hot days, leaving more water for your plants.
If you have a spot that is already compacted, try mixing in some compost. Compost is not only a great way to create poor space in your soil, but it can add a lot of necessary nutrients for your plants. Poor space is basically pockets in your soil that can house air and water and allow for water to drain out easier. Mixing your soil up in general can help you combat the compaction of your soil, but adding something like compost will help a lot more in the long run. Avoid adding sand as something to break up compaction as it can just fill cracks and further add to your soils inability to drain off water. Keep in mind that soil compaction is a naturally occurring phenomenon so don’t get too caught up on it, just take measures each year to deal with your soil before you start gardening. It’s a lot easier to mix up a bed of soil when there’s no plants in it.
Just like the plants in your garden, your soil needs to be thought of and taken care of. From understanding what type of soil is best to use for the plants you want to grow, to adding necessary nutrients your soil type may be lacking, your soil is far from a dump it and forget about it aspect of gardening. Making sure your soil is in good shape is the first and arguably most important step in making your gardening dreams come true. No matter what kind of lighting, watering or ventilation system you have, plants won’t grow in bad soil. Keep that in mind and you should be all set! Thanks again for reading, see you next week!
-Brian Bill