I have my wwn mix that I use for indoor pots and starting seedlings etc. I just mix good compost with medium sized vermiculite, until I like the way it feels. Sometimes I may add in some garden soil, or sand as well, if it seems too light for the purpose.
You may want to add in some sand to the mix for the fig, for exa. :)

"very high-quality mix for my container fig"

High quality as in high drainage? Check out the container forum or look up the 5-1-1 mix by tapla. Or try a Peat/perlite/compost and 1-2 tbl sp per gal of mix of lime.

Do you want to mix your own?

Thanks to both of you for your replies.

I'm a pretty experienced gardener- have made my own mixes over the years and have access to high quality organic bagged options.

I think with all the new options and also after reading tapla's articles on container soil I was starting to feel overwhelmed and confused. I tried finding the things he suggested (bark fines, turface, etc.) and not only could I not find any, I also feel strange about using Turface for my organic figs and other edibles, so I guess there's no loss there.

My hesitation is that I don't know if the industrial process they use to make it leaves residue or potentially creates off-gassing. Maybe my image of Turface as "FrankenClay" is way off, but I do prefer materials I can wrap my head around.

Seems like I started overthinking the soil options with too much new info. in my head, so I appreciate both of your simple suggestions that are helping me come back down to earth!

I just bought a bag of "The Answer" organic potting mix from Costco a couple weeks ago. I am looking forward to using it.

It is from Abbotsford British Columbia so I don't know if anyone else here has ever seen or heard of it.

Here is a link that might be useful: Answer Garden Products.

Another great mix idea, is with biochar, compost and less vermiculite.
What is 'turface' or franken-clay?

Thanks maplerbirch. Do you make your own biochar?

This tells all about Turface:

http://forums.gardenweb.com/forums/load/fig/msg1020504523998.html

No I don't make biochar. I buy the charred oak pieces and waterlog them over winter. Come Spring I bust them up to mix in the various areas.

I advise against using the charcoal briquets and the like, because I haven't a clue what they're made of.

Your link doesn't work, can you give a quick idea as to what it is? Over the years they have always repackaged decent ideas , but rename them in order to be new, improved and cutting edge. :)

That work should link if you put it in your browser box. I think it's clay that's industrially modified with very high heat, and not sure what else. Tried to better post the same link again below, for your reference.

Here is a link that might be useful: Turface Description

I made biochar that came out very high in quality. I soak them in water for a month so they are at a even ph.

It is free perlite.

Turface is baked clay.
Interestingly, Terra Preta has a 'pottery' type element in it, that is expected to house almost as many microbes as does charcoal.

Pulverizing old clay pots would be a good idea for just that reason.
One gardener's trash would be another gardener's treasure. :)

I love it, maplerbirch! Great use for broken pots.

MG1- How did you make your biochar? I've heard several ways, and am curious what worked for you.

"http://www.backwoodshome.com/forum/vb/showthread.php?t=4222";

Thanks to this!!! You are making me want to get out the charcoal chimney and make some up!!!! Now I look at all those dead sticks on the forest floor close by my house as pure perlite!!!!!!!!!!!!!!

This is the safe way and do not get the painted ones, just the metal. I got mine at lowes. I get a mini fire going that is really hot and has good coals then put then chimney on top , which is key, then start from the top with the cooking oil like they show. Then have a metal bucket with water to dump the char in. They key is not letting it turn to ash but not having brown wood left in the middle. Also good to have water by for safety.

There are other ways the go one for a day in a huge barrel with holes in it. It is supposed to be the best way but I find these quik small batches to work very well. I will say Perlite is just really easy to buy and for me that is a win. But if I really had some land, like I want to get soon, I would consider making a lot and using it to replace perlite for my container garden.

Thanks for the biochar info. and the great link. I know what you mean about perlite, but I also think that biochar adds a lot more value to the soil, whereas perlite mainly takes up space. Another reason it may be worth the effort!

An important correction about the role of perlite is in order, I think. Perlite particles hold 3 to 10 times their weight in water (and therefore dissolved nutrients). It holds the water in those tiny little nooks and crannies, preventing rapid loss of moisture to evaporation or gravity, all the while making the water/nutrient solution available to plant roots.

Thus, perlite is not merely a space taker-upper, but plays a very useful and active role in a good potting medium.

Thus, perlite is not merely a space taker-upper, but plays a very useful and active role in a good potting medium.
100% correct

Interesting. Thanks!

What potting soil is NOT organic?

Organic defined: Of, relating to, or derived from living matter.

Turface, perlite, vermiculite, gravel, sand, pumice, and rockwool are all nonorganic, mineral components used in potting mixes. You can grow in any one of those with or without added organic components. In a container, I do think you're better off with a mix that is not 100% organic.

"In a container, I do think you're better off with a mix that is not 100% organic. "

I agree.

That is organic to a chemist. "Organic" to organic gardeners means basically naturally occuring and with limited processing. They would tend to consider ground limestone (or dolomite), sulfur, greensand, normal sand, silt, clay(s), rock phosphate, vermiculite, and perlite all as "organic."

Some good points here. To clarify, I was not referring to the most basic scientific definition of organic, which I'm clear about.

In my region, one has the option of buying nicely packaged sewage sludge(Milorganite), and also bagged matter from factory farms whose runoff kills everything in nearby streams and ponds, which is technically "organic".

I tend to use the term "organic" in the gardening realm in the sense of naturally-occurring materials having no known adverse impact on human health and the environment, (or as little as possible). Although it doesn't matter to me if such materials are certified or labeled as "organic" or not, waste from factory feedlots and hay from fields sprayed with pesticides by the definition I'm using wouldn't be organic.

There may be a better term to get at that meaning, and I'm open to suggestions!

By the way, I ended up using ProMix HP (high porosity) for the repotting of the fig tree that brought this question up in the first place. It'll probably compact faster than I'd like because of all the peat (at least according to tapla/Al's container soil posts that so many of us have read on this forum), but that's what was easy and on hand, so we'll see how it goes.

Thanks for all the input on this topic!

"By the way, I ended up using ProMix HP (high porosity) for the repotting of the fig tree that brought this question up in the first place. It'll probably compact faster than I'd like because of all the peat (at least according to tapla/Al's container soil posts that so many of us have read on this forum), but that's what was easy and on hand, so we'll see how it goes. "

The 5-1-1 is perfect for trees that will be in the same pot for a long time, you really should use it. Now for annual and food crops no need to use the 5-1-1 unless you can get it cheap. Pro Mix HP is one of the best mediums for the money. I think it comes down to money, for me it does anyway.

Just keep potting up every year and water light.

I finally did think of two potting mixes that are (were?) not organic (ignoring here the small amount of chemical fertilizer put in some others).

I have seen neither but read of them.

One had ground up waste styrofoam in place of part of the bark chips. It was to make a light-weight soil for plants to be shipped in their pots. (Come to think of it I possibly did see this one once in received plants.)

The other was far odder and maybe never got past the experimental stage. A powerful mill shredded and pounded household garbage and trash just as collected. Straight from the garbage truck to the mill. Food scraps, boxes, metal cans, plastic, paper . . . everything. Then I believe it was composted for a while and mixed up a bit and then straight to the pots. It was intended for huge commercial nursery operations. I think it was in a Florida agricultural magazine I read this, but long ago.

After I began using potting mixes with more bark than peat, I've never been able to go back to ProMix or other peat mediums. I've been using and recommending Fafard potting mixes, but NOT anything from their typical retail line. Fafard also makes a professional quality line of mediums directed to growers of bedding plants and nursery crops.

These mixes are divided into three main categories, depending upon the percentage of their main ingredients and how they are milled, Light Weight, Middle Weight, and Heavy Weight. I've been using one of the Heavy Weights for many years, both professionally and now that I am growing solely for myself and neighbors.

Since these professional quality mixes are for the wholesale trade and sold by the pallet, I wheedle one of my locally owned garden centers or nurseries to let me buy it by the bale from them. I've never had any problems getting the product I wanted.

Why do I like these products? Because they are very coarse textured, durable, and fast draining. It's almost impossible to compress the oxygen out of these mixes and over watering practically becomes a thing of the past. Plants thrive like gangbusters in these bark based mixes.

Here is a link that might be useful: Let's look at the Fafard products

Good to know about Farfard. Hope they become more accessible soon. Not sure I'll be able to jump through all those hoops, but I'd be happy to stumble upon some!

I've never had to jump through hoops. Just ask your store manager/owner if they use any of the Fafard professional products. If so, ask what kind. If they don't use the kind you want, ask of they'll get some in for you. Fafard has been around for many years...lots of growers and nurseries use it.

A friend of mine went to one of his local nurseries to ask about the Fafard Heavy Weight mixes. They took him out back and showed him a a tractor trailer load of the stuff, on pallets. They were, of course, happy to sell him what he needed.

Thanks, rhizo- good to know.

I've really good results with Dr. Earth Potting Soil.

If we closely examine the role of perlite in container media, we can see several things. First is that the overall volume of water a peat/compost/coir-based soil will hold is reduced on a per volume basis with the addition of perlite. It doesn't really increase drainage or aeration unless it's the primary fraction of the soil; this, because the smaller particles simply compact around the perlite after a few waterings, leaving drainage, aeration, and the ht of the perched water table essentially unaffected. Structurally, perlite's benefit is found in the fact that it reduces o/a water retention.

Perlite, at only .15 me/100cc, has virtually no ability to retain nutrients (CEC); so, if the volume of water held by perlite is used as a measure of its ability to hold nutrients, we'd have to say that soils (based on fine particles like peat, compost, coir, sand, topsoil .....)without perlite held a greater volume of nutrients than soils with it. Additionally, peat (most common container soil base) not only holds more water, it holds it against tensions about 10% greater than perlite.

Actually, perlite holds quite a bit of water @ about 3/4 quart per gallon of perlite. The dry weight of perlite is about 7 lbs/cu ft. Saturated, it weighs about 18 lbs for the same volume depending on particle size gradation, so it holds about 2-1/2 times it's weight in water - or about 11 lbs/cu ft. Peat weighs about 10 lbs/cu ft (dry) and holds 10-20 times it's weight in water, or 100-200 lbs, compared to the perlite's 11 lbs.

So in soils made of fine particles that settle in and surround the perlite particles, perlite offers very little chemically or structurally, other than to reduce o/a water retention, which is a plus that should be considered. Chemically, though it's insignificant, the addition of perlite actually reduces the amount of nutrients held.

In pine bark-based soils though, perlite gets wedged between flat bark particles, which opens channels that DO promote drainage, and create large macro-pores that hold significant volumes of air. In that regard we might consider it more like a valuable catalyst.

Just wanted to set the record straight on what perlite does/doesn't can/can't do for soils.

Al

"The dry weight of perlite is about 7 lbs/cu ft. Saturated, it weighs about 18 lbs for the same volume depending on particle size gradation, so it holds about 2-1/2 times it's weight in water - or about 11 lbs/cu ft."

Saturated it weighs more than the 62 lb/cu ft for water, because perlite sinks, and this is irrespective of the grain size or gradation. You probably mean at field capacity, not saturated.

"Peat weighs about 10 lbs/cu ft (dry) and holds 10-20 times its weight in water, or 100-200 lbs, compared to the perlite's 11 lbs."

It can weigh scarcely more than the 62 lb/cu ft of simply water, the "scarcely" because wet vegetable fibers are just barely denser than neutral buoyancy. The error is probably in how much water it can hold because the dry-weight density for slightly compressed peat seems about right.

Simple technical details are fine here, but they should be correct.

. "It doesn't really increase drainage or aeration unless it's the primary fraction of the soil; this, because the smaller particles simply compact around the perlite after a few waterings, leaving drainage, aeration, and the ht of the perched water table essentially unaffected. Structurally, perlite's benefit is found in the fact that it reduces o/a water retention. "

So how come pro mix bx has LESS air porosity (18%-22%) then promix HP(25-30%). I looked it up before, that is about it.

Bx has 15% perlite, HP has 25%.

I meant saturated, which equates to container capacity, not field capacity, since we're talking about container media. The figures indicating peat holds 10-20 times it's dry weight in water were taken from the first university site I came to listing the physical properties of sphagnum peat moss, though I agree it's difficult to see how a given volume of saturated peat could weigh much more than the same given volume of water ..... unless it has something to do with expansion of the peat fibers when wet.

The point is, perlite doesn't do much for container media based on small particulates, other than take up space that would otherwise be occupied by a more water retentive fraction of the medium. If we desire better aeration/drainage and a reduction in the ht of the PWT, we need to be looking at a soil based on larger particulates instead of a soil based on small particulates and amended with relatively small fractions of perlite.

Al

"Just wanted to set the record straight on what perlite does/doesn't can/can't do for soils. "

Yea........ :)

Pro mix hp/ HIGH POROSITY.....

"It doesn't really increase drainage or aeration "

Thats odd.... that they had pro mix tested and it showed that is really does increase air porosity.

"we need to be looking at a soil based on larger particulates instead of a soil based on small particulates and amended with relatively small fractions of perlite."

That I can agree 100% on. Well said.

"which equates to container capacity"
Thanks Al, my head was beginning to hurt.
The nursery I worked in used sand & old sawdust or ground pine bark, that was it.

To see WHY what I said is true, you have only to picture in your mind's eye a jar of pudding, sand, or any other fine particulates. If you mix 10-20-30% perlite into the sand or pudding, is it going to increase aeration? - NO, drainage? - NO, the ht of the perched water table (PWT)? - NO. It simply occupies space that would otherwise be taken up by the fine particulates and water; this, because the fine particulates simply surround the perlite particles rendering their presence moot, other than for the fact the perlite takes up space that would potentially be filled with water.

Now, in your mind's eye, increase the perlite to 80% of the whole. NOW you can see that the 20% pudding or sand evenly dispersed between the perlite particles has not such a significant effect on the properties I mentioned. Aeration, drainage, and the ht of the PWT have all been positively affected because the soils primary fraction is comprised of larger particles.

Focusing on the physical structure of your container soils, more specifically on the soil's ability to maintain good aeration for the life of the planting is a very worthy cause, and will offer considerably more gain that trying to ensure that your plant's nutrition is supplied via the breakdown of the soil and soil amendments.

The most productive soil I've ever grown in is comprised of equal parts of screened Turface, crushed granite, and screened fir bark. The soil has a 1/3 organic content, and that 1/3 breaks down so slowly that it might as well be considered inert. Why is this so? - because the soil is designed around aeration, drainage, and elimination of the PWT to the greatest degree possible.

Saturated soil kills roots - period ..... and much more quickly than you might expect - within hours. Even if it doesn't kill the plant, it causes the cyclic death & regeneration of the finest rootage - the ones that do the lion's share of the work. When these fine roots die, then are regenerated when air finally returns to the soil, the energy for regeneration is stolen from future blooms, fruits, and increases in biomass. It's an expensive energy outlay, from the plant's perspective.

Al

Al,

I really thank you for showing me bark.

I only use potting mix in a container garden far from the house so they stay wet longer. Otherwise my others on the deck are all in 511, and I have quite a bit on the deck. They really will thrive.

Thanks again!!!

"you mix 10-20-30% perlite into the sand or pudding, is it going to increase aeration?"

Where do you get your information from? I happend to acually be experienced.....

Promix BX Source:www.hort.purdue.edu/hort/facilities/downloads/proMixBX.pdf

Air Porosity:
17 - 22 % by volume (6 inch pot)

Pro mix HP Source www.hort.purdue.edu/hort/facilities/downloads/proMixHP.pdf

Air Porosity:
20 - 25 % by volume (6 inch pot)

What ever Al just said is 100% false, Pro mixes technical data proves so.

Sorry I has to.

:)

Huh? We've had a considerable number of conversations about your sweeping statements/rebuttals that miss the mark; and again you apparently didn't understand what I said because you're not even addressing it obliquely. It doesn't take a lot of research to see that mixing a small fraction of perlite into pudding, sand, or media based on fine particulates, isn't going to have an appreciable impact on aeration, drainage, or the ht of the PWT.

Al

"Huh? We've had a considerable number of conversations about your sweeping statements/rebuttals that miss the mark; and again you apparently didn't understand what I said because you're not even addressing it obliquely. It doesn't take a lot of research to see that mixing a small fraction of perlite into pudding, sand, or media based on fine particulates, isn't going to have an appreciable impact on aeration, drainage, or the ht of the PWT"

"If you mix 10-20-30% perlite into the sand or pudding, is it going to increase aeration? - NO, drainage? - NO, the ht of the perched water table (PWT)?"

You just compaired peatmoss to pudding stating:" is it going to increase aeration? - NO, drainage"

The fact is that promix bx has less air porosity then hp because hp has more perlite. This shows adding perlite increases air porosity in peatmoss.

"We've had a considerable number of conversations about your sweeping statements/rebuttals that miss the mark; and again you apparently didn't understand what I said because you're not even addressing it obliquely"

Please explaine why bx has less air porosity then hp. This is a statment you made:"is it going to increase aeration? - NO, drainage"

So then hp has no more drainage then bx? It has a little?

Peatmoss is not as good as bark but does that to say we now should treat it like pudding? The partical size of peatmoss is quite large.

The fact is you said adding perlite will not increase air but it does, just not as dramatically as when you add it to pine fines... I understand why you compaired peat to pudding and I know you used it as a exaggeration.

I know you are trying to make a point about why peat really is not the same as bark. I do understand using little or no fine particals in a mix is ideal. I understand peat just fills in around perlite, where bark creats the macro pours like you said. It just seemed like you said adding perlite to peat does nothing when it does because I worked with both HP and BX before, thats all.

Does HP have Higher Porosity because it has more dry spots when wet from the perlite? That really is it I would think.

What about soil 'C' with even more perlite than either HP or BX ...... and less air porosity at container capacity because of disparate particulate size in the rest of the media? You take for granted that perlite is the only variable. Scheesch - how many times do we need to go through this same type of circuitous debate? It's not too difficult to 'see' the peat surrounding the perlite particles and robbing them of any appreciable impact, until the perlite together with other large particles becomes the most significant fraction of the medium.

Perlite, in the small fractions typically found in commercially prepared potting media, has very little impact on drainage, aeration, or the ht of the PWT, which is why I chose adjectives like insignificant/appreciable. This is a very simple concept to grasp. Perlite does, however, reduce o/a water retention.

I can mathematically illustrate a tremendous increase in air porosity at container capacity by simply laying a brick in the bottom of a pot - same soil with and sans brick. You have to apply a little common sense, instead of reaching for minutia in order to prove someone wrong.

Al

I bought The Answer organic potting soil from Costco to start my seeds. I thought it would be ok. My seedlings sprouted and got about 2 inches high and then stopped growing. Don't buy this stuff, I think it's sterile or something.

It's not sterile, but it probably is overly water-retentive ..... though there are many possibilities on the list of potential causes.

Al