OK, so the title is misleading. Of course there is no “perfect” potting soil mix that will work well for every type of plant you grow under pot culture. I would love for it to be that simple, but it just isn’t the case.
Over the years I have been tweaking my own custom mix that I use for my palms and tropical plants. Starting with advice from a good friend and slowly improving upon it through trial and error has lead me to a point where I am pretty sure it would be hard to improve upon. Yes, I know that sounds a little arrogant. But the results speak for themselves. I have lost count as to how many times someone who has received a plant from me asks what potting soil I use because they have never seen a healthier, more well-rooted plant. So I figured I would share the contents of the mix I put together. Only share this with your close friends.
The first thing to point out about the potting soil mix I make is that it is not cheap. It will cost you at least double what you would get at a big box store. But for me it is a small price to pay for a much healthier plant and a soil that won’t break down into a sludge as fast as what you get from a cheaper mix. The second thing is you will have to hunt for a gardening center that carriers the brands I use. Most quality garden centers will carry the FoxFarm brand mixes, so it shouldn’t be too hard.
Considering that I am actually “mixing” in a few different potting soils, I like to use a large Rubbermaid trashcan and my trusty garden spade. Another benefit of the Rubbermaid trashcan is that it seals pretty tight to ensure the mix doesn’t dry out.
The first mix I put in is FoxFarm Light Warrior. Light Warrior is marketed as a seed germinator mix. I find that it is a perfect fast-draining, lightweight mix to soften the other heavier mixes I blend in. I use two 1-cubic-foot bags.
Light Warrior is packed with beneficial microbes (Mycorrhizae and beneficial bacteria) to stimulate root growth and enhance fertilizer uptake. It also has humid acid and earthworm castings added to help plants thrive.
The next mix I blend in is also from FoxFarm – Ocean Forest. It is made from composted forest humus, sandy loam, and sphagnum peat moss. It also contains oyster shells, so it is pH adjusted at 6.3 to 6.8 to allow for optimum fertilizer uptake. I mix in one 1.5-cubic-foot bag.
Ocean Forest is loaded with earthworm castings, bat guano, and sea-going fish and crab meal. How awesome is that?
The third and final mix I use is E.B. Stone Cactus Mix. It is a potting soil mix designed for all types of succulents, so you know it has excellent draining properties. I mix in one 1.5-cubic-foot bag.
I use the E. B. Stone Cactus Mix because it contains some things not found in the other two mixes such as fir bark, lava rock, sand, redwood compost, and mushroom compost.
Once all four bags of mix are emptied in the trash can I use my spade to start the arm workout. Thanks to a trip to the emergency room last year to remove a small piece of perlite that flew up and lodged into my eye while mixing, I now use eye protection. And a disposable filter mask.
After a thorough mixing you will end up with what is seen below. Potting soil gold.
Now of course I can’t just state my bold proclamation about my custom mix without proof. So currently I am running a growth comparison to give it a little scientific backing. Right now in my greenhouse I have some plants growing in my mix and some in another cheaper mix and I will blog about the results in the future. In the meantime, if you haven’t been happy with your current mix, give this one a try. Please come back and share your experiences here in the comments of this post if you do experiment with it.