Vermiculite will collapse (structurally) pretty quickly.

I use 511 mix for my house plants and it works great. Healthy plants, no fungus gnats, steady growth, and if I throw some controlled release fertilizer in the whole thing becomes very low maintenance. Granted, I'm not growing anything that is even a bit difficult - peace lily, pothos, spider plant, strawberry begonia, fiddle leaf fig, grape ivy, etc.

When you say “quickly” how quick do you mean?

I've had it turn to mush in as little as a few months.

Yikes. I wonder why they include it in the mix? It has some great reviews, but 5:1:1 has a bit more experience behind it.

What did you use for the bark in yours?

Bonsai Jacks sells fines that are sifted to 1/4 inch and I love the consistency of their “gritty” mix.

I also use the 5-1-1 for all my houseplants besides the cacti and succulents and for all my outdoor containers as well. I don't think there is a better mix and I have been using it for going on 25 years!!

Vermiculite is very absorbent and that is its downfall. Once completely saturated or having absorbed as much as it can, it will collapse and compress. It doesn't have to take months....I've seen it do this in a matter of a few weeks!

I am lucky enough to have found a local supplier for pine bark fines. One of my local nurseries sells bags of "soil conditioner", 6 bucks for a few cubic feet (2 or 3 I think, I can't recall), and it is pine bark in almost the perfect size. It tends to have a bit too much fine material, so I sift it through a 1/16" insect screen to remove the very fine stuff, and then instead of adding peat moss I just add back in however much of the very fine stuff I need - I always have enough.

So, in speaking with the owner of a local garden store here, she showed me this potting mix which is almost exactly what is needed with the 5:1:1 except for the perlite which I bought separate. I got 30 dry qts for $10.

Do you think a 50:50 mix of this and the perlite would be best? Or less perlite?

I guess I’ve never seen a picture of the 5:1:1 to be able to compare.

That looks prety good, depending on actual particle size. But 50-50 with perlite is probably way more perlite than you need. OK for cacti and succs but the 5-1-1 only has 1 part perlite to 5 parts bark!!

JG - Would you provide an image of what's in the bagged of soil you showed. It's a product specifically packaged for use in the landscape, but what's written on the bag doesn't necessarily disqualify it from being used effectively for potted plants. I'm concerned it might be much too fine for container medium.

The following addresses your original inquiry. I just can't keep up with you guys!! ;-)

The ratio of water to air in a soil is a very important consideration. Plants absorb moisture most efficiently from a microscopic coating of water on the surface of soil particles and from water vapor in larger pores between soil. They absorb water poorly when it's trapped in its liquid form between soil particles. As the size of your soil particles increases, the amount of water found between soil particles after a thorough watering decreases, and disappears entirely when the size of soil particles is approximately 1/10". Since moist and never wet/soggy is ideal, soils with the least amount of water occupying the spaces between soil particles, all else equal, are going to offer plants better opportunity to realize their genetic potential.

The best way to achieve this arrangement is by using a LOT of particles larger than 1/10", and a small fraction of particles smaller than 1/10" that serve as a way to fine tune water retention.

Changing gears to address your questions:

This mix consists of:

Choir

Fine Vermiculite

Small Stalite

Small sponge rock (perlite)

My questions are:

Has anyone had any experience with this mix or a mix like this? I haven't used this particular soil because it has properties I consider undesirable and I am certain I can make a better soil for much less $, though I freely admit that making my/your own will take some small amount of time and effort. That said, I've never driven a bus, either, but I still know what makes the wheels go 'round and 'round.

If the ingredients are listed in order of the volume they contribute to the soil, I think you'd be better served if you just bought a bag of Permatill (by Stalite) or other expanded shale product, of which there are many, mixed it 50/50 with appropriate size pine bark, added a little peat to adjust the water retention and a bit of lime to provide Ca/Mg and adjust the pH upward a bit, and used that or variations thereof, depending on the plant material you're working with, and called it a day.

If you're interested in knowing why I have reservations, aside from the water retention issue, I'd be pleased to explain.

Al

Al,

Thanks for your response. Here is a picture of the soil on the bag.

If it is too fine, could I offset it with more perlite or sift out the smaller stuff?

If it is ok, what would you recommend my perlite to soil ratio be?

It looks a bit more composted than I would prefer, but I think it's still quite usable, though I think you'll need more perlite than you would with a less composted product. I'd try a plant or two in

3 parts of what's in your hand

2 parts of coarse perlite (if coarse is available - usually is in very large bags [4 cu ft is the norm])

If you find that 2 water-retentive, you can use a wick or add some ballast when you establish your plantings. Ballast, used appropriately, is a very effective antidote to excessive water retention.

Al

What do you recommend for ballast if I need it?

I have used lava rock in other plants, but have also been told to use charcoal.

There are all sorts of things you can use as ballast. Bricks, empty soda bottles, blocks of foam, over-turned pots, blocks of wood, .....

After you read this, ask any ?s you might have.

Al

So, how do I know how night the PWT of this soil is?

I don’t think it is giving me the free flow of water that should be coming from a 5:1:1 mix. It seems to hold and if I tip the pot, I can get a bit more to drain out.

How do I know if it is draining “enough” to benefit the plants and do you think the gypsum is a negative factor?

Lastly, this is the mix after I ran a bit of water through it. Do you think the bark is too fine?

Thank you for your advice!

That first question was how to tell how high the pwt is?

So, how do I know how night the PWT of this soil is? Get a clear plastic cup at least 6" deep - heat a nail or screw and use the head to melt a hole through the bottom of the cup - seal the hole with tape that won't come loose, or nest the cup in another cup exactly like it - fill the cup with your soil and fully saturate. It should soak for an hour or so. Top off water as needed - remove the tape or lift the cup with soil out of the cache cup and allow it to drain - you'll be able to see delineation between soil that is completely full of water and soil that has air between the larger particles - that is the maximum ht of the PWT for that particular soil.

Make a note of the information. You'll want to know if you need to use ballast. Your ballast should be arranged so it's at least the ht of the PWT. Make sure you understand how to use ballast effectively. I have no question that your soil will work well if it needs ballast, and it may not. You might be able to eliminate nearly all of the PWT by use of a wick. To test - push a toothpick up through the drain hole once the cup has stopped draining - note how much additional water exits the cup.

I don’t think it is giving me the free flow of water that should be coming from a 5:1:1 mix. That's fixable. We don't care how fast the water drains, only that it does. It seems to hold and if I tip the pot, I can get a bit more to drain out. Any planting that utilizes a soil that holds perched water will do that. Compare line drawing B to A below. The shaded area represents the PWT. You can see it's the same ht in all of the pots (except E). When you tip A to the position in B, the PW column gains ht. This increases it's gravitational flow potential. IOW, there is more weight pushing down on the water below it as the water column increases in ht - just like stacking bricks on a pallet. Every brick added increases the weight pushing down on the lower bricks. In the case of the PWT, the added weight pushes the water below out of the drain until the PWT returns to whatever it is. Try the experiment with a saturated sponge. Hold it flat - like a deck of cards would lay on a table - until it stops draining. Then, change its position so the longest dimension is vertical. You'll witness a LOT of excess water draining from the bottom of the sponge.

How do I know if it is draining “enough” to benefit the plants and do you think the gypsum is a negative factor? Ideally, you want the PWT to be from 0-1" in ht. Once you get to that point, you can water at will to the point of saturation, not withstanding fits of lunacy that would find you watering daily or more frequently. ;-) I'm not sure why the gypsum was included, but since it's represented at a lesser amount than the lime, I wouldn't be concerned. It doesn't change pH and plants are rather flexible when it comes to the Ca:Mg ratio in media.

Lastly, this is the mix after I ran a bit of water through it. Do you think the bark is too fine? The PWT test will tell, but even if it's too fine w/o ballast or a wick, it's still going to be usable. Don't worry - you're on the right track.

Did you mention where you live? Just a large city near you is all I need - not asking for an address. ;-)

Al

I live near Cedar Rapids, Iowa. (Zone 5a/5b)

I will test the soil for PWT and look in to possibly using a ballast. I also found a cheap source of pine bark fines (1/4) that I’m going to add to the mix to make it closer to a normal 5-1-1 mix.

I’m not planning to report all the plants until spring, so I’ve got some time to experiment and find the best mix.

Thank you for all of your help and advice!

I don't doubt for a second that you'll be more than ready, with a really productive medium by spring.

Until next time ..... Al

Al,

When you say "coarse" perlite, what size are we talking about, exactly? I have a great hydroponics store nearby that has everything from typical Espoma products which are pretty small diameter, all the way up to these giant nuggets that are over an inch! Should it be in line with the bark and sifted to 3/8" - 1/2", and leave the dust and smaller bits out? Or do we sift out large and small and use what's left? If the latter, what size small screen are we aiming for?

Some bags have sizes on them such as: #2, #3, #4 etc.

This question has been on my mind for a year and I can't recall ever asking you, or maybe I did and all the information is coagulating in my noodle.

How to read this info: of a given sample size of coarse grade, 5-30% is retained above a 4 mesh screen - the rest passes. 65-70% of what passes the 4 mesh is retained above the 8 mesh screen - the rest passes. 90-100% of what passes the 8 mesh screen is retained above the 16 mesh screen.

To determine what % passes the screen, subtract the %s retained from 100%. IOW, if 5-30% of the sample is retained by 4 mesh, it must follow that 70-95% passes.

Coarse, or "propagation grade" should consist of

4 mesh or 3/16" w/ 5-30% retained (by volume)

8 mesh or 3/32" w/ 65-70% retained (by volume)

16 mesh or 3/64" w/ 90-100% retained (by volume)

Medium, or "soil mix grade" should consist of

6 mesh or 1/8" w/ 0-10% retained (by volume)

8 mesh or 3/32" w/ 40-50% retained (by volume)

20 mesh or 1/32" w/ 90-100% retained (by volume)

I don't use nearly as much perlite as I used to, but I keep only these 2 grades on hand, and I often mix them together at various ratios, depending mainly on the size of the bark I'm using for the 5:1:1 mix.

Al

Here is my final mix. Is 3 parts pine bark fines, 2 parts outdoor container mix (composted pine bark fines, sphagnum peat moss, dolomite lime, and gypsum), and one part coarse (larger than 1/8) perlite. That PWT experiment works great btw. This mix produced pretty much 0 PWT with no “drainage” later. Al’s advice is spot on here. Looking forward to some happy plants around my house (and little to no bugs)!

Here is my final mix. Is 3 parts pine bark fines, 2 parts outdoor container mix (composted pine bark fines, sphagnum peat moss, dolomite lime, and gypsum), and one part coarse (larger than 1/8) perlite. That PWT experiment works great btw. This mix produced pretty much 0 PWT with no “drainage” later. Al’s advice is spot on here. Looking forward to some happy plants around my house (and little to no bugs)!

Actually, it’s supposed to be 4 parts pine bark fines. I assumed that one part of the bagel container mix consisted of half pine bark fines and 1/2 peat. So, I counted 2 parts as 1 pb fines and 1 peat.

Hi Joey,

That Hoya looks happy but pls. be careful w/ that double potting. Looks a pretty tight fit & makes me wonder abt checking for water collecting in the bottom of the outer pot which could rot your Hoya's roots; just so you know. I grow Hoyas too ;>)

I should keep them separate?

Never mind, I see what you were saying. I water them outside of the decorative pot, then once it’s drained well enough, I put it back in.

Al, if you’re still following this post, I have one more question about the 5-1-1 mix.

Once I’ve switched the plants over to it (3 pothos, 2 peperomias, a philodendron, and a Hoya), will I need to water them more often until they get acclimated to the soil?

Thank you!

Thank you Lantana! That is exactly what I was looking for. I currently have all of my succulents in a gritty mix, so I’ve been through the switch before. I just wasn’t sure if I would need to water more frequently at first to help the roots become established.

No problem! When I have repotted plants I give them a good drink right away then water as needed, I don’t do any additional watering beyond that. I’m not sure if extra watering would help/harm/or be neutral to the plants roots, hopefully someone else can answer that part of your question.

Hi, Joey. Over the course of the last few days, I've been spending more time at the citrus forum than I normally do in debate about the impact the air:water ratio in media has on the likelihood of root rot, and it's effect on root health and the o/a potential of the entire organism/plant.

https://www.houzz.com/discussions/lemon-tree-losing-green-leaves-dsvw-vd~5607649 

I'm still following here, though.

Joey asks: Once I’ve switched the plants over to it (3 pothos, 2 peperomias, a philodendron, and a Hoya), will I need to water them more often until they get acclimated to the soil? First, if you haven't repotted many plants, I think you might want to alter your soil a bit and do a do-over. If what you have in your palm is representative of the entire batch, you're probably going to have too little water retention - unless you enjoy watering. If the whole batch is just like what's shown, I'd add 1 more part of perlite and another part of peat. The perlite will get between the bark flakes and create more air porosity, which will largely be filled by the peat. The result will be a soil with more water holding ability (in the peat) with no (or VERY little) sacrifice in total air porosity or air porosity at container capacity (when the soil is saturated but has stopped draining). Your plants won't really acclimate to the soil. They'll want the same conditions no matter what medium you use, you'll just need to water more often. This does not mean the potential in your soil is diminished because of its porosity, not at all. Unless it gets to extremes, the more often your planting needs watering, the easier it will be to keep plants happy. You just can't forget to water at appropriate intervals, and have to be up for watering more often. Personally, I'm excited for you. I think you've done a really great job and should expect a pleasing return on your investment.

Good advice from Lantana & Karen, BTW.

Al

I repotted a few of them to test it out.

Do you think I should repot them now? Or wait to see how it goes?

The issue I had was trying to factor in the bagged mix and approximately what the mix of peat to pine bark was. So I figured 2 scoops of the bagged mix would equal 1 scoop of each.

Do you have a picture of a good mix so I can compare the consistency?

I was more focused on eliminating the PWT and getting the ratio right.

Thanks for the help!

Here is what it looks like with your suggestions:

Joey, I am in Cedar Rapids also and trying to make gritty mix and 5-1-1 but am having trouble finding pine bark fines. Could you tell me where you found yours? I have been to quite a few stores and garden centers looking for it.

Illstep are you in Iowa? Just wondering where the nursery that sells pine bark fines as soil conditioner is at. Could you share name & location? I have been searching all over Cedar Rapids looking for it.

Hi guys,

The main part of the mix I used came from earl may. The mix contains partially composted pine bark fines, sphagnum peat moss, and lime. So, it’s pretty much everything except the perlite.

Originally, I just used 3 parts of the potting mix with 2 parts perlite. This mix was ok, and works great with a wick, but after adding 2 more parts of just pine bark fines, I was able to lower the PWT to almost nothing.

Hope this helps! Feel free to ask any more questions about it you might have!

Do any of you have an Agway nearby? The attached photo is what you want. Show them this photo and any Agway can cross reference it. Sometimes it is packaged in Agway brand bags, my local store doesn't do this as it costs $1/bag more.

Hope this helps!

Sorry, I forgot to say that I got the pine bark fines online from bonsai jacks on amazon.

Treegeek, unfortunately we do not have Agway our here.

Went to Blooms on Blairsferry Rd and left my name and what I want -Pine bark fines -for the person who orders supplies to check & see if it was something they could order. Treegeek, is this product - pine bark fines - almost all useable for our gritty mix & 5-1-1 or is there a lot that can't be used? If it's good, I can show her this picture & that might help sway her to order some.

Joey how much is the bonsai jacks bpd & how much is shipping?

*pine bark

It keeps correcting me. I mean pine bark fines.

Mary Joe, checkout this thread I started and added many photos to. I think once you see the material needed, it will all click, I hope!

Screens are so cheap and take 10 minutes to make, at the very least pass it all through a 1/2" screen/wire cloth to get the big chunks and long sap wood pieces removed.

Main link here: https://www.gardenweb.com/discussions/5552410/pine-bark-fines-for-511-boston-area-help

Treegeek: can you post a picture of the contents of your Pine Bark from Agway? What I get is the Agway brand which is pretty good and mostly usable for 511 straight from the bag. A prior discussion on Agway bark is here: https://www.gardenweb.com/discussions/5217373

Bonsai jack stuff is sifted for bonsai purpose (1/8-1/4) as far as I know. Shipping will be expensive, I would think.

TG: Never mind your link has the pics.