Medium or soil is a mixture (no pun intended) of your personal preference, environment, and what plant you are dealing with. There is not one true answer to any soil question and there are different ways to go about all of it. That being said, this post should explain what each medium is, what it is typically used for, and where you can find it. Let's dive in!
What does "potting mix" or "potting soil" mean?
There is only one big difference which is the presence of soil versus lack of soil. Most people will use these terms interchangeably and the same amendments like peat moss, vermiculite or bark, for example, can be found in both.
Potting Soil: This is usually best for outdoor use and gardening since is more dense and heavy. As is, depending on the company and product, it may not be optimal for most houseplants unless other amendments are added. Because it contains soil, there are more nutrients to feed your plants.
Potting Mix: This is a mixture of medium ingredients that does NOT include soil. You may ask, well what does it contain? This is made of whatever ingredients are chosen but commonly seen ingredients could be peat moss, coco coir, perlite, vermiculite or bark. This is usually better for houseplants since it is created to be a lighter weight, more aerated mixture. Since it doesn't contain soil, nutrients will need to be added and you may need to replace or refresh the mixture more often.
All the ingredients:
Soil: SSSA defines this as "mixture of minerals, dead and living organisms (organic materials), air, and water."
Compost: this is decaying organic matter usually used for soil amendment and plant fertilizer
Sphagnum Peat Moss: light weight moss that can still retain moisture.
Peat is known to have some negative environmental impacts but there are ways to do it more sustainably. I've included articles at the bottom of the page that offer insight to this topic if you are interested!
Peat Moss: decayed version of sphagnum peat moss, looks closer to a soil texture, is also a light weight ingredient that can retain moisture.
Coco Coir: Usually used as an alternative to peat moss since it is also a light weight ingredient that helps to retain moisture.
Perlite: granular mineral that increases aeration and drainage.
Vermiculite: increases drainage while retaining moisture and nutrients
Sand: usually used to help with aeration in heavier soil.
Charcoal: this can provide drainage, can trap soil odors, remove acids from your mix, and has antibacterial properties.
Pumice: porous lava rock that helps with aeration and drainage
What do soil recommendations mean?
Well draining: Usually a standard potting soil or mix that allows water to flow. Adding perlite, bark or any amendment to increase drainage helps.
Chunky, coarse: Usually doesn't contain soil and has large ingredients like bark, sphagnum peat moss, leca, perlite, coco coir or coco husks
Moisture retaining: Usually can contain soil with a mixture of coco coir or peat moss to increate aeration but still hold moisture
What are some potting mix companies?
Obviously there are the large, well known companies like Scott's Miracle Gro and Sun-Gro Black Gold, Home Depot's Vigoro which mostly specialize in the potting soil and gardening products but do carry some houseplant specific products.
Here is a list companies you can find almost anywhere that typically are more conscious of their ingredients, customers, and impact:
FoxFarm Soil & Fertilizer Company: I personally love this brand and have continued to use their soil and fertilizers for years. This company was born in the 1980's in California with a "desire to offer a different kind of garden soil that was not sterilized in any way". They do specialize is gardening soil and nutrients but their products do work well for houseplants as well. Their customer service is amazing, I've reached with question and received answers quickly so if you have specific questions they will help you!
Sol Soils: This recently founded, Minneapolis based company, has a line of potting mixes, soil amendments and even soil toppers. Their peat-free potting mixes are extra chunky so this is a great company to use if you want a chunky soil but don't want to buy all the individual ingredients. They also plant a tree for every bag sold to support Eden Reforestation projects.
Good Dirt: I've also seen this company sold at small business and they have landscape and indoor planting options. They have a potting mix and other nutrients but they've create one unique product called "Dirt In A Box". This is a sustainable way to bring you potting mix that didn't get packaged in plastic.
What do I use for my medium?
This depends on the plant but here the breakdown of what I usually do:
There isn't one answer though! I invite you to try new things as you figure out what works for you and your budget! I didn't want to make the mixture too complicated for myself so I was willing to purchase a higher quality soil and only a few amendments to alter the mixture as plants needed different specifications.
I always ask followers if they had any specific questions, opinions or hot-takes I can address in this podcast and blog. Here are the questions and answers for this topic:
"What is the best medium to propagate in?"
I don't think there is a right answer here and I plan to do a propagation episode in the near future! I personally think water propagation has worked well for me but I know many people that have successfully propagated in perlite, perlite soil mixture, sphagnum peat moss, coco coir, and leca. I promise, more to come on this topic!
"What is the difference between pon and leca? Is one easier to use than the other?"
Pon is made basically smaller sizes gravel and Leca is balled up baked clay. I don't think either are easier than they other but here are some tid-bits that can help you determine what you would rather use:
Pon is usually more expensive than Leca.
Pon retains moisture more than Leca.
Pon is much heavier than Leca.
Both reduce potential for some pests like fungal gnats and mealy bugs
You usually need to remove 100% soil when using Leca but don't need to be that picky when transferring to Pon.
Usually you need to prep Leca but rinsing and soaking it before use.
"Do you use DIY soil?"
"Have you found a good way to store your media? I mixed some together and it molded."
I dump my bag of soil in a plastic storage container and, if it fits, I put my bag of perlite and bark in the same bin on top. I've needed to cut holes in it for aeration because it has molded in the past. I also keep in a dry environment to help reduce mold.
"Dirt. Dirt is my hot take 😆"
This is hilarious and I am going to turn this funny comment into a fun fact! Did you know soil and dirt are different? Soil is alive with organisms and organic matter while dirt does not support any life. The more ya know!
IN THE COMMENTS, TELL ME WHAT TYPE OF MIXTURES, BRANDS, OR INGREDIENTS YOU LOVE!
WANT TO LISTEN?
Go to Apple Podcasts, Spotify, Audible, and more! Search for Houseplant Homebody to hear this episode and MANY more! You can also listen directly on my website under the Podcast page!
DON'T FORGET TO FOLLOW!
Stay connected on Instagram, Facebook, TikTok, & Pinterest @houseplanthomebodyllc.
SAVE, COMMENT, LIKE, FOLLOW, SUBSCRIBE, and SHARE.
All your engagement on my podcasts, blogs, and social media posts help other plant lovers find me too!
Always written with extreme plant passion!
Love, Holly (Owner & Creator of Houseplant Homebody LLC)
Peat Moss Articles:
*NOTE* Some product links are commissionable affiliate links. Thank you for purchasing through the linked products!*