Aroid Soil Mix

As I have learnt more and more about growing plants indoors, I have come to realise how important it is to put focus on the soil you grow your plants in. Often growers rely on a one size fits all situation and plants with different needs are all put into the same potting mix that does not allow the plant to thrive and be its best.

As I have started moving into growing mostly plants from the Aroid group, I have focused my soil on what replicates their natural environment. Most Aroids grow on the rainforest or jungle floor in soils made from rotting leaf litter and bark. Its full of nutrients and light and airy in texture. The soil must free draining. It must be able to hold water but not become soggy, which can cause roots to rot and other issues in these plants.

So this is what I have experimented with recreating for my Aroids. Its probably not perfect and it will probably be tweaked as time goes on. Especially as I learn more and resources available to me change.

My Aroid Potting Mix.

6 Parts Bark
4 Parts Perlite

4 Parts Coconut Coir
1 Part Compost
1 Part Charcoal

* To measure my ingredients out, I tend to use a small plastic pot or what ever is handy at the time.
* Make sure you mix well because there is nothing worse than finding a heap of perlite thats been hiding at the bottom of the pile when you have already used the majority of your batch. Its annoying and messes with your ratio. I learnt the hard way to add this last, at the top of the pile. If any are going to miss being mixed in, its the perlite.
* Originally I used equal parts bark and perlite. But with bark being cheaper and more available, I altered the mix to suit my needs. The quantity is still the same, both are there for drainage, so its ok to do this.

So, what does each ingredient bring to this mix?

Bark: It adds larger particles to the soil. This allows for good drainage and prevents the soil becoming water logged. It makes the soil porous, allowing water to run through easily, taking air with it, down to the roots. It is best aged or composted, both for at least 12 weeks. Fresh bark will have a high carbon to nitrogen ratio and can deplete the soil of nitrogen. In this case, extra nitrogen will need to be fed to make up for this loss. Bark is relatively cheap and can be bought in bulk and stored for a long time if you have the room. I am currently using pine bark from Bunnings. Its cheap, less than $10 for 40lrs. You can buy graded bark, but in this case I went for the smallest and most consistent grade. Nothing over 3-4cm. Landscaping places are the hest if you need bulk bark. It will last a long time and is a cheap option. As an alternative, you could use a good quality orchid mix that contains both bark and charcoal. Just swap the mix for both the bark and charcoal percentage.

Perlite: A mined Volcanic Rock product. Great for drainage and light weight. This reduces the overall weight of the mix. Great for large pots and your back. It also keeps the soil ‘lite and fluffy’, stopping impaction that blocks drainage and leads to root rot in Aroids and simmilar plants. Its a porous material that holds water, increases humidity and traps air, providing it to the roots. The good thing is that it dosnt break down or loose its ability to provide its benifits to the soil. Its a product that will stand the test of time and keep benefiting your plant. Alternativly, You could also use vermiculite or volcanic rock. Personally, I am not a fan of any of these. But I have come around to perlite and what it does for the soil. I now use it in my mix and am seeing the positive effect it has on the plants.

Compost: I make my own compost. Im a bit of a nerd about it to be honest. I choose to use compost because it holds water and feeds the plant. It basically replicates all the rotten down leaves on the rainforest floor. I like to sift my compost to remove anything thats not fully broken down. One negative, if you can call it that, is you sometimes get a few weeds shoot up from the soil. If your lucky, you might get something worth transplanting like a tomato seedling. Alternatively, you could use a good quality potting mix or buy commercial compost to replace home made. Just swap it for equal parts. If you can also get some Worm Castings to add to the compost, then your plants will only thank you. Some people like Kalee Ellen use castings only and not compost. This is probably why her plants look so damn good. So if you can get it, then go for it. I plan to raid my mums worm farm next time I am at her place.

Coconut Coir: This is a bi-product of coconut processing and is readily available in Australia. It is sold in compressed bricks for a few dollars and expands when added to water. It is seen as a more sustainable alternative to sphagnum peat and is much cheaper to buy. Its role in this soil is water retention. It wets easily and holds onto water, but at this percentage of the soil mix, it isnt enough to cause problems with becoming soggy. Sphagnum peat is of course an alternative, but is more acidic than coir, which has a neutral P.H.

Charcoal: Horticultural Charcoal is the most expensive part of my soil, but its worth it. It assists with drainage and makes the soil lighter in weight. It also is porous allowing for oxygen to be stored within it and around the roots. Its tiny air filled pours also allow for beneficial microbes to live and grow within, creating a healthier soil. Other pure hardwood and aquarium charcoals can also be used, but be careful that they are purely made of wood.

So there you have it. My Aroid Potting Mix. There are many variations of this recipe available online. It is important that you do your own research and understand why each element is included in the soil.

I learnt early on that your basic “premium” and “well draining” potting mix’s, are just too wet for these plants and in the early days of me growing aroids, I lost a few plants to root rot. Also, dont get me started on the fungus gnats that have piggy backed their way into the house via these store bought soils.

Come Late 2019 and I have completely repotted all of my plants in an adjusted mix to the original one I used. The reason being that my first mix was a little too heavy on the compost and the bark alone wasnt doing enough to drain moisture away. I lost a lot of plants again to Root Rot and had to admit the defeat of my original mix. You really cant over look the draining properties of your mix.  I have given in to pearlite and changed my bark mix to pine bark. I cant help but wonder if my original bark had broken down over time. But the formula is basically the same, but for a few adjustments.

As you can see, its important to do your own research and experiment with what works for you. But one thing is for sure, your soil is a very important element to your success in growing aroids!

Feel free to comment and add any thoughts you have about this mix.

Thanks for reading and happy growing. Xx