Soil & amendments:

Choosing your houseplants soil and amendments is one of the areas many plant hobbyists struggle. I am often asked about what soil mix I personally use because people want to replicate it, unfortunately, it is not always this simple. Every plant keeper and plant is different, and will require different amendments and ratios. Heavy waterers will want to use a very chunky soil mix to avoid issues with overwatering and root rot. Busy plant parents who don't have time to water often might need a heavier soil that retains water for longer periods of time.

Each plant has individual care requirements that need to be considered as well. Cacti and succulents like sandier soil that doesnt retain water for long periods of time, so adding perlite, charcoal, pumice, lava rock, and other chunky amendments is important. Certain species of cacti, such as mesmbs like lithops and conophytum, do best without any soil at all and require extremely gritty mixes. If you're unsure of the type of soil your plants needs, look to its natural environment. Many of the plants we keep in our homes are actually epiphytic, meaning they climb on trees, and like a bark heavy soil mix. 

Now that you have a better idea of your plants needs and your own capacity for caring for it, you can begin to build your soil mix. First, we'll look at some of the most common soil amendments and their role in plant keeping.

Pumice/perlite: Great for adding aeration to the soil without increasing water retention. Perlite will eventually be squished and break down.

Lava rock: Great for adding aeration to the soil without increasing water retention, great surface for roots to grow

Charcoal: Horticultural charcoal is similar to bark, activated charcoal can absorb impurities and nutrients

Bark: Great surface for roots to grow, adds aeration to the soil, adds nutrients as it decomposes, great home for beneficial soil insects like springtails and mites

Sand: Assists with increasing water retention while providing additional aeration, dries out quickly for drought loving plants that can uptake their water quickly

Leca: Adds aeration to the soil without increasing water retention, great surface for roots to grow on, great for soilless mixes

Pebbles, grit, and other rocky additives: Too large pieces will eventually sink towards the bottom of the pot, but these are great for adding aeration while getting zero additional water retention, good addition to sand to decrease it's likelihood to compact when wet

Other things to consider: How often you are able to water, your average temp and humidity, how often you use heat or AC, your pot type, proximity to windows/doors and temperature control units. All of these factors will play a role in your plants water needs, which can help you better customize your soil mix for optimal success. 

Unglazed terracotta pots will absorb the moisture out of your soil, which means your plants will need to be watered more often. Using a chunky or soilless mix in conjunction with terracotta in plants that aren't drought loving will result in severe underwatering unless you water constantly. Pots with minimal or no drainage holes are more likely to have water logged soil, and will do best with chunky mixes to avoid the roots standing in soggy soil.

Now for the actual soil part of your mix:

Personally,  I am not picky when it comes to my soil base. I prefer coconut coir over peat, but both are good choices for the plant. I have even used cheap top soil from the hardware store, and as long as it is properly amended, this will work great. A lot of the more expensive or "boutique" soil brands are expensive due to the nutrient content, and often still require amendments. It's easy to add your own nutrients to your DIY soil mix though, so these are not required unless they are your personal preference.  I will discuss nutrients further in a future article. 

Plant keeping and mixing your own soils is a very personal experience. It is important to take all of these things into consideration if you want to have the best success with your houseplants. Incorrect soil is one of the main causes of issues I see in houseplants, and it is often incorrect by the suggestion of someone online. This is why I prefer to present people with the information they need to make an informed decision, instead of telling them exactly what I am using. My current plant experience is very different from the vast majority of people, due to living in South Florida, so what works for me, may not work for others. 

If you're having trouble with your plants or need help creating a custom soil mix, I am always available for assistance via DM or email.