I have experimented quite a bit and come up with this “recipe” that I think is the best aroid soil mix. I use this for all my aroids, which include aglaonema, anthurium, monstera, philodendron, pothos, syngonium, and ZZ plants. I also use it for my hoyas and all other houseplants but orchids, African Violet, and begonias.
I generally have a fine mix on hand for smaller pots and a more chunky mix for pots 4 inches or larger. Feel free to adjust things to meet your needs.
Why Make Aroid Soil Mix?
Normal potting soil most big box stores and large nurseries use is mostly made from peat moss and a little perlite. This is great at retaining water but doesn’t let very much air get to the roots of the plant and this suffocates them.
Especially over time as the roots grow and the soil becomes more compact from watering the soil gets even more dense and you start having all sorts of problems with your plants, like brown or yellowing leaves or root rot. It is very easy to over-watering plants in a mix like this and suffocate them.
What is Aroid Soil Mix?
My special blend is a mix of orchid bark, coco coir, pumice, charcoal, and worm castings. The goal of this mix is to provide moisture, nutrients, and air to your plant’s roots. It is important to try to get about the same size of each of these ingredients so there are small air pockets but also so more dense items don’t work their way down to the bottom of the pot and suffocate the roots.
A good mix will allow the roots to grow and get plenty of air and water and will help prevent overwatering of your plant.
How do you make aroid soil mix?
Time needed: 30 minutes
The trickiest part of making this can be finding the ingredients. Read the section below this one to find out all my favorite brands (and ones I don’t like) and why and where to buy them.
- 5 parts orchid bark
Why? It helps with nutrients, drainage, aeration, and stronger roots.
- 4 parts coco coir
Why? It helps with nutrients, moisture, and drainage.
- 5 parts pumice
Why? It helps with drainage, moisture, and aeration and is far superior to perlite IMHO.
- 2 parts activated charcoal
Why? It helps with aeration, draws out impurities, odors, bacteria, increases PH, drainage, and less fertilizer will need to be used.
- 2 part worm castings
Why? It helps with aeration, fertilizing, and keep pests away.
Where to buy – I buy mine on Amazon for $33.98 for 25 quarts or I use them from my worm farm.
An Alternative to the Pumice and Charcoal
Pumice and charcoal can be very hard to find locally and can be expensive so as an alternative I’ve started substituting the 5 parts pumice and 2 parts charcoal with 7 parts of Lechuza Pon. It is very consistent in size and quality and is made of pumice, lava rock and zeolite and the zeolite is a great replacement to charcoal.
What is the Best Orchid Bark for Aroid Soil Mix?
I have tested many brands of orchid bark so you don’t have to. The trick is to find some that is only fir/orchid bark, has the same size pieces in the bag, and is the right size for the pots you have.
Fertilome Orchid Mix
This is a mix of sphagnum peat chunks, red fir bark, hardwood charcoal, and volcanic lava rock. First of all, I don’t like mixes because I don’t how much of each ingredients is in the mix. A lot of this mix is peat moss chunks, which I don’t like, although they could be used instead of coco coir in a bind. The fir bark was fine, but there wasn’t that much of it and it had a huge range of sizes. The charcoal also had a large range of sizes. I don’t generally use lava rock in my mix, but it’s very similar to pumice and could be substituted in your chunky mix.
What I ended up doing is separating everything out and making individual piles for different uses. It was a bit tedious but I had a large pile of peat chunks, which I broke up and throw on some low spots on my lawn, I separated the bark into fine and chunky piles, I separated the charcoal into fine and chunky piles, and put the lava rock into my chunky mix in place of some of the pumice.
Conclusion – I do not recommend it unless you have an extra hour or two to kill or unless you don’t care that much about your mix because it could actually be a decent mix on its own for medium-size pots.
Gubler Orchid Grow Mix
I found this at a big box store for $6.48 for 4 quarts so it’s actually quite expensive. It’s only ingredients are fir bark and chunky perlite. I picked out the chunky perlite and used it in my chunky aroid mix and used the bark in my chunky mix. I did not feel like separating out the bark into the various pieces.
Conclusion – It’s alright, but expensive and the bark has inconsistent sizes and is large enough it should only be used in 5-inch pots and up.
E. B. Stone Organics Orchid Bark
I liked that this was only bark, but it had very inconsistent sized pieces and most of them were huge – like they would only work for an 8-inch pot or larger. I ended up separating out the sizes and I am slowly using up the huge chunks in my chunky mix by using one part of it and 4 parts of my favorite bark. It bought it for $8.47 for 8-quarts at my local garden center.
Conclusion – Most of the chunks are way too large.
Uni-Gro Fine Grade Orchid Bark
This is my favorite mix for two and three inch pots (which is mostly what I have because that’s what I start my cuttings in to sell). I buy it at Sun River Gardens in Orem, Utah for $7.99 for 8 quarts. Look for it in independent nurseries. Make sure to buy bags with a big “FINE” sticker on the front because the regular mix is huge.
Conclusion – It is very good quality and has similar size pieces of fine fir bark. The biggest drawback is that it is hard to find.
Zoo Med Premium Repti Bark
In a moment of pure desperation after I cleaned out all the stores around me of orchid bark after bleaching all my plants I tried the pet store and was very glad that I did! This is slightly larger than the Uni-Gro brand but it is consistent in size and very clean. Try to buy it on sale because the regular price is $14.99 for 10 quarts, but the national pet stores often have it on sale for a good deal. I got mine on a buy one, get one half off deal. It is even available online if you can’t find it locally.
Conclusion – It is good quality, has similar size pieces of fine fir bark, and is easy to find. I use it in my fine aroid mix.
Thrive Fir Bark Bedding
This is also available at national pet stores and is normally $29.99 for 24 quarts but it also goes on sale fairly regularly. It is clean and has consistently sized pieces and is my favorite to use for 4-inch pots and up.
Conclusion – It is good quality, has similar size pieces of fir bark, and is easy to find. I use it in my chunky aroid mix.
What is the Best coco coir for Aroid Soil Mix?
Urban Worm Coco Coir
I like to use this for my two-inch and three-inch pots. I buy mine on Amazon because it is good quality and a good price.
MegaMulch Expanding Coconut Coir
It buy it from Costco in the spring and summer and stock up for the rest of the year, which isn’t hard to do because it comes in two huge blocks that last for a long time. I use it in my chunky aroid mix.
I buy mine locally for $6.99 for 8 quarts. I can’t find a good online source for it. An alternative is perlite, which is affordable and easy to find but I don’t personally like it. Another substitute would be lava rock but I haven’t used it much myself so I can’t make any recommendations.
This is relatively easy to find and will work for the chunky mix. Some of the pieces are really large. It does not have consistently sized pieces but as far as affordability goes, it’s a good choice.
Sprig Stone Charcoal
I prefer this for my fine mix because it has consistently small pieces. I get it on Amazon.