Cultivating a thriving indoor garden begins with one fundamental element: the right potting mix. Soil is one of the most over looked aspects of plant care. Most people don’t even consider soil when they think about plant care, but it is so important to a plants over all well being. The soil beneath your house plants isn’t just a passive medium; it’s a dynamic environment that can significantly influence their growth and vitality. In this guide, I will go over the important components of soil, my two favorite soil mix recipes, and what plants I put in both.
Components of a Healthy Potting Mix
Water Retention
Water retention refers to the amount of water your soil mix will hold onto when you water it. Most soil mixes are centered around peat moss. Peat moss is popular due to its high water retention. However, it can hold onto too much water for too long, causing the roots growing in the soil to die off from root rot. Another aspect of peat moss I’m not fond of is that it becomes hydrophobic when it dries out. If peat moss becomes hydrophobic, water will pool on the surface, or roll off the sides, and out the bottom.
So, when peat moss dries, and needs water the most, it is the least absorbent, and when it is wet it stays wet for too long. However, I still think peat moss is one of the best growing medias for house plants, but a good soil mix definitely needs some additional amendments. The best amendment for balancing out water retention is perlite. Adding perlite is a great for reduce water retention, as its porous structure holds very little water.
Aeration
Aeration refers to the availability of air within the soil. Adding aeration is an important factor to consider when making your own soil mix, as it can save a plant from root rot. People tend to think plants suffer from root rot because they have too much water. While that is true, it is more specifically caused by the lack of oxygen for the roots. This is why plants propagate in water with out rotting.
Peat moss is very dense, and compacts over time, to the point that it can actually suffocate roots. My favorite amendment for adding aeration to soil mixes is Orchid potting mix. Orchids are so sensitive to root rot that growers have manufactured a soil free potting mix for them. Good orchid mixes will include orchid bark, horticultural charcoal, and course perlite. This chunky mix will create air pockets in the soil, and helps prevent soil compaction.
Nutrient Content
Nutrient Content refers to the nutrients in the soil available for plants to absorb. Microbes in the soil slowly break down organic matter, like peat moss, and orchid bark, into nutrients, but very slowly. In nature, animals and insects help speed this process along, but at home your plants will use up nutrients faster than they become available.
If you are really good at regularly watering your plants with a liquid fertilizer, you don’t have to warry about this step. However, if you are like me, and frequently forget, consider adding a slow release fertilizer to your soil. I use Osmocote Outdoor & Indoor, and it has worked great for me.
Best DIY Soil mixes
Unfortunately, plants are usually sold in a sub optimal soil. If you bought a plant growing in straight peat moss, or peat moss with very little perlite, I recommend repotting it. However, before repotting it, if you just brought it home, give it a week or so to acclimate to your home. Too much change can shock your plants, so, it is best to wait.
I have two soil mixes I use for all my plants, my chunky aroid mix, and my well-draining soil mix. My chunky aroid potting mix is for all my pothos, philodendrons, hoyas, and monsteras. My well-draining potting mix is for my begonias, calatheas, marantas, and my small plants, in 2-3in pots. Luckily, most ingredients for both can be found at your local big box store. However, I prefer to buy my perlite online. The Miracle-Gro perlite they sell in stores is too fine for my liking.
Remember, these mixes can always be adjusted to your needs. If you are an over-waterer, add more perlite, and orchid mix. If you are a chronic under-waterer like me, add less! That is one of the benefits of making your own soil mixes, you can change it to fit your plant care style.
Chunky Aroid Potting Mix
- 1 part potting soil
- 1 part coarse perlite
- 1 part orchid potting mix
- a Sprinkle of Osmocote*
Well-Draining Potting Mix
- 2 parts potting soil
- 1 part coarse perlite
- 1/2 part orchid potting mix
- a Sprinkle of Osmocote*
*I add a sprinkle of Osmocote to each plant as I pot it up, not to the soil mix as a whole.
Often times when it comes to indoor gardening, the groundwork for healthy plants lies in the soil mix. Often overlooked, soil plays a critical role in the well-being of plants. I hope this guide helped you understand the importance of soil in your plants overall health.
Thank you so much for reading, and if you have any questions, or additional tips, feel free to leave a comment. Good luck, and happy growing!