How to Make Your Own Potting Soil Mix
Whether it’s an indoor herb garden, or a succulent spread in a planter box, container gardens are a great way to scratch that gardening itch this winter. The first step to any DIY container gardening project is to make sure you have the right potting soil. When you go to the store you may be overwhelmed at all the potting soil options available. I know I was! I didn’t want to waste my money on unnecessarily fancy soil, or buy soil that was too cheap. On top of that, potting projects that have multiple containers need quite a bit of potting soil. Buying enough pre-packaged soil for your projects can really add up. Do not get overwhelmed! Did you know you can make your own potting soil? This article will go over potting soil basics and teach you a few easy recipes to make your next container gardening adventure a success!
What Is Potting Soil?
Why do we need potting soil? Can’t we just use the dirt that we use in our gardens? Potting soil is very different from your regular garden soil. The biggest difference between garden soil and potting soil is the weight. Potting soil is made to be lighter and more airy than your typical garden soil. This helps the water to evenly distribute from the top of the container to the bottom. The reason you want an even distribution of water is so the roots of your plant stay healthy. Roots that get too much water can easily rot. Garden soil, on the other hand, is designed to bring water down to the roots and keep it there.
Ingredients Found in Potting Soil
Potting soil is generally contains three main components: A growing agent (the base of your soil), something to help moisture and nutrients stay in the soil, and something that promotes drainage. The growing agent is the base of your soil. Typically your soil falls under one of two categories. It can either be soil based or peat based. Soil based mixes are most common, although peat based mixes have become more and more popular in later years.
Peat moss is formed when moss and other living material and plants die than decompose within a peat swamp. Because, the moss is dry, it is typically a light brown color and may need to be rehydrated before mixing it in your soil. It is similar in a lot of ways to compost that most home gardeners grow, but because moss is the primary ingredient is much lighter than a typical compost. Peat moss is used to aid in aerating, and because it holds water so well, it is used to keep the soil moist.
Some potting mixes use sand. The sand, like peat moss, is used to aerate the soil. However, unlike peat moss, sand is heavy and doesn’t hold water so it cannot aid in the hydration of the soil.
Perlite is a lightweight expanded volcanic rock. Perlite also doesn’t retain water, which is what makes it such a great draining agent.There are a few downsides to using perlite in your mixes. Because it is lightweight it can work its way to the top of your potting soil. It can also be expensive. When using perlite always pre-soak it before adding it to your mix. This helps eliminate the dust that can be harmful if inhaled.
Vermiculite is often used alongside or in place of perlite. It is a clay that can expand which helps it hold air, water, and nutrients. The downside to vermiculite is that it compacts easily which lessens its ability to hold air and water over time.
Over time potting soil leaches the nutrients that plants need to thrive. Adding a fertilizer to your potting soil will need to be done regularly. You can fertilize your soil by adding organic compost to the tops layers of soil, amend the potting soil with limestone before you use it, or adding fertilizers that offer slow-release nutrients.
Tools Needed to DIY
It may seem like a hassle to make your own potting soil. However, potting soil can be made in large batches, and these batches are easily stored between potting projects. This will save you time and money in the long run. Gathering the correct tools will make mixing your own potting soil an easy and painless process. You will want large buckets or containers for measuring and mixing; small hand held tools such as shovels, and trowels; a container for pre- soaking materials like peat moss, or vermiculite; safety goggles, gloves and mask to avoid inhaling dangerous dust particles; and a large container with a lid for storage after mixing.
Finding the Right Potting Soil Recipe
You can find a variety of different potting soil recipes all over the internet. Do some research and find a recipe that will best suit your needs. Double check that the PH of the soil is in line with what you are growing, and adjust as necessary. Some recipes will give you an exact measurement of ingredients, while many recipes simply call for “parts”. When mixing your potting mix it is important to keep ratios even. As long as you use the same container to measure all ingredients to keep the ratios the same, it does not matter if the container is large or small.
Soil Based Potting Soil
When building a soil based potting soil it can be as simple as buying loam, or gardening soil, from your local garden center or home store, and mixing in equal parts compost and sand or rock. When buying your soil from a home store or local nursery look for organic if you can. Garden soil is often pre-sterilized which means that it is made to deter weeds, bugs and diseases that can be associated with soil that is pulled straight from the garden.
- 1 part garden soil
- 1 part compost
- 1 part sand
Peat Based Potting Soil
Peat based potting soil is also referred to as soilless based potting soil. Peat based mixes are mainly used to help seeds germinate. Once seedlings grow you can re-pot to bigger containers and use a soil based recipe. Peat based mixes are made up of peat moss, perlite and/ or vermiculite, and added fertilizers.
- 2 parts compost
- 2 parts peat moss
- 1 part perlite or vermiculite
Making your own potting soil can be a cost efficient and fun way to take control of your container gardening. Using the correct ingredients and tools will make mixing your own potting soil an easy process. So the next time you get the itch to fill a planter box, instead of running to the store for your pre-packaged potting mix, try your hand at mixing your own. Your plants, and wallet, will thank you!