for my future fig collection:

1/3 part coconut coir
1/3 part mushroom compost
1/3 part composted pine bark 

+ chicken pellet fertilizer?

I find this mix to have twice the volume 240L compared to Premium mix which only yields 150L for $60 compared to the $35-40 of the custom mix. 

All will be grown in non woven fabric bags.
Thanks!

I'd check pH.  Also check wicking properties if you're going to water from below.

Not sure if you need the fertilizer with all that mushroom compost. 

I would think it would hold too much water. I'd think you'd want to use pine bark fines instead of coir.

Nice idea.
I would agree and skip the coco coir and go with peat moss and some perlite to lighten up the bulk of the mushroom compost. I would also go lightly with the added fertilizer. 

Agree with Coop 100%!

Thank you all for the replies. are there any other ingredients i can use to substitute and still keep the coir? or adjusting the recipe so that it does not hold too much water? I will be growing them in fabric bags and they tend to dry out the mix quicker than a standard pot so would that be a major factor as well? 


The Peatmoss is expensive here in Australia. $5.98 for a 5L bag! and perlite has a going rate of $8.98 for a 5L bag. compared to $15 for a 90L cube of coconut coir!

~i agree with frank and coop too ~

I'm going to break ranks and take the opposite opinion on the peat moss. While peat moss may be better, it's not better enough to justify a 7X price difference. Coco coir is a serviceable alternative to peat moss. Coir often needs to have a calcium source added to counteract its high concentration of potassium. Toss in a generous amount of dolomitic lime (which will benefit the figs for almost all mixes), and you should have a workable potting mix.

Young fig trees are sensitive to having too much moisture. More mature trees are more tolerant of the potting mix and should be ok as long as the mix drains well enough to not be waterlogged. The proposed mix looks a little wet for young trees, but is probably fine for a more established tree in a fabric pot. Personally, I use a 5-1-1 mix (Pine bark-peat moss-perlite) for my young trees, and drop it to a 4-1-1 or 3-1-1 as they grow bigger. For a SIP, I alter the mix to a 2-1-1 ratio for better wicking. I substitute calcined clay oil adsorbent from the hardware store for perlite, and I imagine substituting coir for peat moss would also work.

The exact mix you use is dependent on your local climate, how mature your trees are, and how big a fabric pot you're using. I'm just going to guess and say that you could probably increase the composted pine bark content to 50% and still have a good balance of moisture retention and drainage.

I found this healthy young fig growing in southern Italy didn't seem to care about the soil at all

It's growing in a coir tree!

I have just set up 4 experiments Ratio = Coir-Composted pinebark-compost

• 1-1-1
• 0.5-2 -1 
• 0-1-1
• 0-1-0

Picture of the experiment in a fabric hanging planter, same materials as the fabric pots im buying:

 

A picture of  the composted pine-bark if anyone's wondering what mine looks like:

I'll update and let you know how the experiment went.

For anyone who is interested, after a week i determined that the 1:1:1 mix was the way to go. I could even make it 1:0.5:1.5.

I noticed that:

1. The 1:1:1, 0:1:1 and 0.5:1:1 mixes had a good amount of moisture, nowhere near too wet or soggy. It retained moisture quite well during the week.
2. The 0:1:0 mixture was slow to drain and was the wettest