Generally I'm happy with my current soil mix but it's on the expensive side. I'd like some opinions on a mix I've been thinking about. I understand that many people use some kind of pine bark based soil but that is not available in bulk in my area. I've been thinking about using well decomposed tripple shredded root mulch. It's basically just whole trees run through the shredder 3x and then decomposed for a few years. It's pretty dark. (I'm not worried about nitrogen issues.) So I'm thinking of using 2 parts tripple shredded root mulch, 2 parts well decomposed leaf compost, and 1 part Pro Mix HP-CC.

The Mulch and Compost should hold water and the Coir in the HP-CC should provide good aeration.

This mix will be used when I shift up my 3-10 gallons to 15 gallons.

Do you think this will work?

Whole trees ground up would be a problem. Given that you are in NJ, perhaps you could just buy Fafard 52/Nursery mix. Some places sell it for around $5 a cubic foot. I am not sure if that would be cheaper or not for you, I only have 5-6 pots. 

I have about 200 15 gallon. @ $10 per pot for Fafard 52. (or similar). Generally I would agree that wood chip is not a good idea, but if it's shredded fine and decomposed, why not?

Haha well dropping 2k on a repot is rather crazy. I'm sure other high volume growers have much better suggestions. 

Every grower by me uses a peanut shell/ pine bark/ peat blend. (Which they bring in about 75 yards at a time). I can buy it from them for about $100/yd. (corrected pricing) I've been buying that and mixing it with other stuff to drop the cost down to $5 (price is still accurate) per pot. I'm looking to go lower than that.

You should be able to buy 60 cubic foot totes of metro mix 852 for 180 or so per tote. Check with your local crop production services.

Hey Aaron - I have easy access to pine bark quite cheap so that remains the main component of my 5-2-1-1. Pine bark, perlite, peat moss, manure/castings

Might I ask:

I know you recently got in to bunny poop. Will you be including that into your mix? I've always had one part of my mix as manure but will be slowly switching over to worm castings if they perform well. 

What is your current mix?

I know many use sand as a draining component. I've used granite based sand in the past. It seems to work well and it's cheap but a bit heavy.

Joe, I don't think sand would be good at improving drainage at all. Something like perlite would be much better.

I do use perlite now as my two parts....

The sand did seem to drain very well. It did seem to matter what kind of sand I was using... For instance a lot of limestone seems to cake up good. 

Here is my link to last years mix. I had the $200 number in my head and I was remembering that as the nursery potting soil price alone. That price by itself must have been $100. Not $200 as I wrote above. That does change things a little, but mulch is $14 so still much cheaper.

I understand that most people would not use it. The question is why?

Bunny poop, worm castings, or any other fert does not figure into the volume of potting soil. (Yes I'll be using all of that too)

Very gritty sand or pea gravel seems to be ok, but the finer parts of the sand tend to settle to the bottom and clog up all the air pockets making a dead zone in the bottom of the pot. I don't use it because 15 gallons is enough weight for me and I will need to root prune at some point and don't want to deal with gravel. I've been thinking that a sawzall will be my weapon of choice.

I'm going to correct my math above.

http://figs4funforum.websitetoolbox.com/post/busy-day-yesterday-8254263?pid=1293505717

I've not found a bulk supplier in my area for the faffard, or similar product larger than a 2.8cf bail. (About $33 each) which gives me 4 15 gal pots.

I used the sawzall to root prune a few times. Works great. Just don't use a blade you plan to use for anything else again....

Thanks for the mix link

Have you tried reaching out to CPS? There is a location in north and south NJ.

Hey Aaron - Just occurred to me. One of my neighbors has a big property and goes through tons (literally) of mulch every year. He found a local tree service that couldn't get rid of their chipper waste fast enough. A couple of times a year they dump a truck load of bark mulch on his driveway. I think he tips the driver a case of beer for his trouble. You certainly want to be choosy about what's ground up in there and maybe need to plan ahead to compost a bit but if you have someone like this in the area that you can look up it might be a good source for you. Assuming the content is appropriate.

I'm also looking into a city program here. The city has a program giving away free leaf compost from public yard waste collection. Maybe something similar exists in your area or near by.

Just ideas...Not sure if they fit for you but hope it can help.

If looking to reduce costs, I'd question what value the high priced Pro-Mix adds at only 1 part of 5. It's about 75% peat which I would think is there to retain water but you already have 2/5 leaf compost to do that.

I'm kinda in the same boat. Looking at a 3k up pot in a few weeks..
A few years ago when they were trimming trees around here I had them dump about 5 truckloads of material on the property. I added horse and cow manure and mixed it every season so its now ready to use... I'll be using that, peat that I will buy from Lowes and then worm castings and rice hulls. The rice hulls are in place of the perlite.

Best price I found on the worm castings and rice hulls was here  http://www.7springsfarm.com/black-castings-40lb/
You can do a search for the rice hulls there as well.

Then I will probably add some of this fertilizer just to be sure..http://www.seedranch.com/Dynamite-All-Purpose-Select-Indoor-Outdoor-Plant-F-p/dynamite-organic-7.htm

I'm not sure on my exact mix yet but will have all ingredients on hand to mix whatever I decide I like best.. I was doing the pine bark that I got from wal mart for 2 or 3 bucks a bag.. Seems like that mix is to light and dries out very quickly. I hand water and really dont want to water every day.

I use about 175 yards of wood chips a year to mulch between my garden rows. The tree companies know where I live. That stuff will not be going in my pots.

The compost I buy I can also pick up for free, but if I want it loaded into my truck I have to pay. Not much. It's mostly leaves but will have grass clippings, small sticks, etc. it's well decomposed. At least 3-4 years old.

The ProMix I was thinking of using is the CC. It has chunks of Coir in it. I've never used it before, but I thought it would be good for drainage and aeration. It does not break down very quickly.

How many 1 gallon pots can you get out of a 2.8 cf bail of pro mix, fafard, sun mix, or whatever. Not sure I'd make a custom mix if all I needed was 2-300 gallons. I saw the sun mix today. It looked exactly like what I've been looking for. However I'm talking about 3,000 gallons. That's just the shifting up of existing pots. Then I have the 400 3 gallon pots I'll need for the cuttings I'm rooting now. Many of those will find their way into 15 gallon pots by fall so figure an easy 7,500 gallons by the end of 2017. What is that in yards? I have no idea. I was going to start with 4 yards because that's what my truck will hold and go from there. 8 yards maybe?

I have ProMix HPCC and I can say that it is excellent so far. I have it mixed 45% ProMix with 55% AllGreen Microbark. Chunks are very evenly sized, about the size of a standard dice cube. 

Hmmm....Sorry the ideas weren't more helpful. 

I wonder what the big nurseries are doing? I can't imagine they're forking out that kind of cash for their mix... 

No TJ the nurseries are not. They buy it by the tractor trailor so it's much cheaper. I can buy what they use for around $100 per yard, so what do they pay? $50-$75? The problem is that although it has most of what I want, it also contains peanut shells. I've heard that peanut shells are not good for figs.

I didn't know that about the peanuts...Thankfully we don't get them here.... There must be a better way... I'm not up to your scale but enough that it's going to sting come repot soon. I'm going to keep thinking on this. If anything comes to me I'll let you know....

Since I'm not in business, this is all an expense to support my addiction... At some point I may need to start selling some trees locally just so I can afford to grow them...