If you’re new to gardening you may not be aware that you can mix your own potting mix. Creating your own potting mix isn’t as difficult as it sounds and is quite a satisfying project. If you have kids it’s also a great way to get them involved or interested in growing their own food.
There are numerous benefits to mixing your own potting mix. For example:
- You know exactly what nutrients and ingredients are in your dirt.
- It is economically beneficial. Buying bags of potting mix is expensive!
- It ensures you won’t accidently expose your garden to pesticides, herbicides and other chemicals found in some store-bought potting mixes
- Allows you to tailor your potting mix for different purposes (i.e. a custom herb mix, a custom tomato mix, etc.)
- Teaches you how to properly add ingredients into potting mix to revitalize it
But there are some challenges to mixing your own potting mix. If you only have a couple of potted plants, you may not save very much money mixing your own. Similarly, buying potting mix ingredients in bulk will take up space, which is a downside if you live in a city or even impossible if you’re in an apartment. Storing one bag of pre-made potting mix would be better than having to store multiple bags of potting mix ingredients.
Now, let’s get into the common components of good potting mix.
What Makes a Good Potting Mix
There are a couple of different potting mix ingredients you need to familiarize yourself with before going down to your gardening supply center. You can make your potting mix as simple or as complicated as you want, depending on what you are growing. Since this article is aimed at new gardeners, the ingredients listed are those that are the most basic.
The terms “potting mix” and “soil” are often used interchangeably. In this article, potting mix will refer to the mix you plant in while soil will be the dirt foundation to which you add other ingredients.
Let’s look at our ingredients:
Soil is going to be the bulk of what a basic potting mix will be. Soil is often quite cheap or even free. If you have good dirt in your garden or around your property, use it! You also can purchase a good quality organic soil from a local garden supply shop. You can choose to sterilize your soil or not. Sterilizing kills pests and weed seeds but also good bacteria. It is a personal choice, but if you do buy from an outside source, sterilizing by laying the soil on a tarp in the sun for a month might be a good idea.
A good compost  is what really makes the difference between poor quality potting mix and nutrient-packed potting mix. You can make compost, buy compost or take some from a mature pile. Compost is packed with nutrients and healthy bacteria.
Sand seems like it would be a bad material when it comes to growing plants, but this isn’t the case. A good quality coarse sand is what breaks up the density of your soil and other potting mix components. Sand allows for water drainage and helps seedlings root more easily without sacrificing stability.
Peat Moss or Coir Fiber
Peat moss is also known as sphagnum moss and is quite a popular potting mix ingredient. The purpose of peat moss is to help the potting mix hold water better and overall add more substance to the mix. Coir fiber is a coconut fiber and does exactly what peat moss does. Peat moss is not a sustainable product and does cause a negative impact on the environment. Coir fiber is more expensive than peat moss but a much better choice for the environmentalist.
You’ve probably seen those little gold-colored rocky specks in store-bought potting mix before. Vermiculate is very common in potting mix because it adds minerals like calcium into the mix while also helping the soil foundation hold more water. (Organic vermiculite is available.)
There are some other things you can add to your potting mix such as bone meal, lime, perlite and shredded bark. Generally, you don’t need these things for a very basic potting mix, but they do have some benefits. For example perlite functions like vermiculite and can also be an alternative to sand. If a soil test shows your potting mix PH is too acidic, add lime.
Putting Together Your Potting Mix
Once you’ve bought your ingredients and sterilized your soil (if you chose to), you can start mixing your first batch of potting mix.
First off, do this outside, as mixing up dirt is going to get very messy. You may also want to use a surgical mask or a bandana over your nose and mouth to prevent inhaling any particles. A large plastic tote or even a large empty garbage can work well for mixing and storing your potting mix. You will also need a trowel, a wooden dowel and some gloves so you can really get in and mix everything together. Make sure you prepare your ingredients ahead of time by soaking the coir fiber and vermiculite.
This basic recipe for a potting mix involving the above ingredients is:
- 2 parts soil
- 1 part sand
- 1 part compost
- 1 part peat moss or coir fiber
- ½ part vermiculite
Mix this up until it is thoroughly combined. If you purchased some other additive like lime or bone meal, follow the instructions on the package to ensure you don’t put too much into your mix. Once mixed, you can use this in containers or in raised beds.
Mixing your own potting mix is a lot of fun and educational. It promotes self-sufficiency and gives you the knowledge on how to add things to improve your own garden. This recipe is very, very basic but a good place to start. Don’t be afraid to customize it to your liking and your growing zone.
What is your advice for making potting mix? Do you use a different recipe? Share your suggestions in the section below: