For you guys that use Epson salt. I don't think it's nessesary ever, unless you know your mag is difficent. If your using standard lime you probably have more than you need. To much mag is common and causes a host of issues.

And these so called mycorrhizal products are known for being dead on arrival. You can look up labs testing the top brands. Most are way under label postings or even no readings. You can search yourself. I suggest you Save your money for other items.

no one uses sand ?

A couple of years ago, i had thrown some papaya seeds out
and they landed in pure sand i was using for a low spot in the yard.

those papaya were growing fast, and looking healthy.
i think papaya have a high silica demand.
i think figs do as well.

i also add sand to just about everything.
i love the drainage, particle size,
and the fact that it slowly leaches silica.

Ive also noticed something else with Diatomaceous Earth.
When i add it to compost, or, to anything heavy in organic matter
it seems the microbes and other soil life LOVE it,
all the way up to earthworms.
ive used diatomaceous earth with excellent results
on several plants besides papaya.

That said, ive also started paying attention to particle size.
When i use certain compost and the size seems too large
coarse sand fills in the gaps, while still providing drainage.

Composted coffee grounds have a great size for drainage
and provide a lot of nutrition as well.
just an observation.

Brad

If your looking to give your plants silica there are better products. Does the silica in sand actually get released. I doubt. What about rock dust powders. There are most 80 percent aluminum. Is that getting released to plants. If it is I think the aluminum would kill the plants. If you test your basic backyard soil it contains just about every element in certain portions. What makes each one available for plants is another story. If I was abrasive there I didn't mean to be.

I think the worms ingest the DE to break down there food. Like chicken gizzards.

I think the term "compost" is too general. Composted what and for how long? It's like saying " add 10% dirt". What's compost to me can be entirely different than compost to you. Your results could vary wildly from good drainage to a soupy mess...just sayin'.

As the years go by I've simplified it a lot.  I use 90+% pine bark. All I add is whatever's cheap for fertility (tomato tone, compost, worm castings, whatever) and mycorrhizae (Dr Earth, usually) and sometimes some pro-mix HP bio-myco for the pathogen eating bacteria and a little extra Glomus intraradicies. Pine bark holds water pretty well so I don't think the calcined clay is all that necessary plus it adds weight that I don't need. I add some Osmocote plus or Dyna Grow Grow for trace elements as needed.

Apparently... there is more than one way to grow a fig.
I'm growing about 250 figs in pots. I need a lot of potting soil. I probably go through 2-3 yards per year. I don't have the budget or time to make a complicated mix.
Here's my mix. Take it with a grain of sand.
All ingredients go into my truck in layers.
1 yard of premade potting soil from a nursery (mostly peat moss and pine bark fines. Some perlite)
1 yard organic topsoil. (Good stuff a lot of composted leaves)
1 big bag of perlite
6 bags or so of pine bark fines

As I take it out of the truck it gets mixed up.
I can't comment about how well it works as I don't have enough time with this mix.
Works out to about $2.50 per 3 gallon pot.

I'm wondering about mixed wood chips decomposed for about a year. (From a tree company) Anyone ever use those?

Through many fig collectors in LA, I learned that after the 3rd year you can start mixing garden soil with the mix gradually, until by the 5the year the entire pot should consist of 100% garden soil.
This way it becomes very affordable.
The only withdraw of this is that the pot becomes heavy.

I keep hearing about fine ground Pine Bark. Where can you find? I keep hearing I need it for my Blueberries.

@macmike, depends on the part of the country. I would think down where you are it's mostly a waste product, though you may have to pay a little more to get it ground into small chunks (if that's what you want, I don't know that blueberries would care if it's being used as mulch). You may be able to get it delivered by the yard.

Up in the mid atlantic where there's not a lot of softwood harvesting I find it in bags at my local Agway (ag supply store). We mostly have hardwood bark as mulch.

I get PBF at Agway but it's also available at the Depot sold as Soil Conditioner.

http://m.homedepot.com/p/Timberline-1-5-cu-ft-Soil-Conditioner-50055100/203732162

Look for "soil conditioner" at your local big box store.

My mix is similar to those listed, yet different. I wanted to go over a few things. Someone asked if perlite holds more water than Turface - calcined clay. Perlite does not hold any water. it is only used to help water pass through. It increases drainage. On clay, I don't like clay. The pores are too small for roots to directly remove water, it has to leach into the substrate. DE (diatomaceous earth) has much larger pores that roots can access. It holds 30% more water too. I'm not talking about powder, but particles the size of perlite.
I would not add anything you don't need. For example I don't use rock phosphate because phosphate toxicity is super bad for plants. It also inhibits manganese and iron uptake. It inhibits mycorrhizal activity too. Compost has plenty, no need to add more. Here's a reference from the famous Linda Chalker-Scott, Ph.D., Extension Horticulturist and Associate Professor,
Puyallup Research and Extension Center, Washington State University
https://puyallup.wsu.edu/wp-content/uploads/sites/403/2015/03/phosphate.pdf

bump

I use a loam based Compost (75%) and the one I buy comes with added grit in it plus (25%) perlite. Loam is a fertile soil of clay and sand containing humus. Loam is considered ideal for gardening and agricultural uses because it retains nutrients well and retains water while still allowing excess water to drain away. I was also told by an experienced gardener that figs thrive in loam based potting mixes. I also add trace elements in early spring. Followed by high 'P' fertiliser (dynagro bloom) till summer followed by high 'K' fertiliser. Works well for me in my rainy English weather and I don't store my trees in garage, they all stay out in rain all winter.