Any indoor gardener will tell you that the most important factors for plant health are water and light. And they aren’t wrong! But as we progress along our houseplant journey, it’s important to understand the true home our plants live in: their soil. We’re not suggesting you set out to create your own soil mix from scratch, but we want to equip you to know what you’re looking at when you’re in the potting soil aisle at the nursery.
Basic potting soil should give you everything you need to get started on your houseplant journey, especially if you’re starting with common houseplants. However, if you’re starting to notice a change in leaf color (brown or yellow spots), or your plant is losing leaves, or if it’s simply not showing you the growth you were hoping for….it may be time to reassess the soil you’re using. Here are some soil mixture components we think you should know about:
- Peat moss: peat moss is usually not sold on its own, but as part of a potting mix. It’s simply a moss that’s harvested from bogs! It acts as a sponge, absorbing extra water and helping soil retain moisture. If you’re interested in mixing your own potting soil, don’t neglect this key component!
- Perlite: Did you know that most potting soils - likely one that your plants call home - contain volcanic glass? Perlite is a white, rock-like substance that is mixed into practically every potting soil. It’s made by heating volcanic glass until it “pops” like popcorn! It’s lightweight, almost like packing peanuts, and this helps your plants by providing lots of space in your soil for air circulation. It also helps to absorb a little water, but it’s not as effective for this use as vermiculite.
- Vermiculite: Similar to perlite, vermiculite is a light, airy substance made from heating silicates (a chemistry term that you only need to know about if you want to look it up) until they expand. This expansion allows this substance to not only absorb, but also retain water. This is a great add-in for plants that like a little extra water, or plants that don’t get watered as frequently as they should.
- Bark chips: Bark chips are a great substitute for peat/perlite in large pots. They’re less dense than these other soil components, and water drains easily through them. Alternately, if they are soaked with water for upwards of thirty minutes, they will hold water that will be released slowly into your soil. And, they eventually decompose, which can act as a compost for your plants!