Nan's Nook : Archives : Botanicals : Cactus : San Pedro : Growing San Pedro : Cactus Soil
Posted by: ion Aug 08 03, 05:35 AM GMT
The original formula hasn't really changed since it's been posted on the net, but I'm sure it took Nan a while to develop it to that point.

So here we are. This is where we explain what the deal is with Nan’s soil mixture, and discuss a few recent developments. Whodathunk there’d be so much controversy over dirt? cool.gif

Nan's Soil Mix

The Mix

Nan's Soil ™ :

1 part topsoil
1 part compost (derived from manure or not)
1 part crushed limestone (minus grade, see figs. 2 and 3)
1 cup of pelletized dolomitic limestone per gallon of mixed soil

Optional Ingredients
These are not part of the original formula! They are things I’ve realized that some preparations are lacking, because in various parts of the world our “compost”, “topsoil”, and “limestone gravel” are often very different from what Nan originally used.

Sand: For seeding mix or low-sand topsoils with high clay content:
1/10th part desert sand (not beach sand) per 1 part of topsoil in the mix
- Check your topsoil for clay... sticky balls that squish rather than break up, often orange or grey on the inside, coated with black dirt. If there is a great deal of this clay, then mix in some sand and break up the clay balls as much as you can.

Aerator: For any Nan’s Soil ™ mix:
1 part aerator material (this should be pumice or kiln fired clay)
-Just mix this in with the soil as normal.

About the mix for seed sowing (more at this link: http://www.nansnook.com/archives/tek/ionseeds.htm )...
For seeds, you want something that will have a relatively flat surface, not porous and bumpy like potting soil. The reason is that you don't want the seed to fall too deep into a crevice, but you still need lots of surface contact... a firm, flat soil surface will indent just a tiny bit, but the seed won't get lost down into the mix. This is why I use the original Nan's soil (mixed with a bit of sand, but no chunky aerator material), finely sifted, for seeds... it's firm and relatively compact (but not too much), it doesn't dry out very quickly (seeds have to remain moist), and it contains all the nutrients and the correct pH for the seedling.


“So… do I just mix this stuff up, or what?”
Essentially, yes… but in case you’ve never done this before, I have a section for you… smile.gif

Tips and Tricks

-- Use an empty gallon water jug with the top cut off... this works as a large "measuring cup" for your materials, so you know more precisely how many “parts” you have of each.

-- Mix topsoil, compost, and aerator material, breaking up chunks as you go, before adding limestone or pellets… your hands will thank you. Lime (pellets, powder, or stone) has dehydrating properties on the skin and can burn a little, and rocks are… well… rocks!

-- Use one of those large, wide galvanized tubs for soil mixing. It makes it easy to get up to your elbows in the dirt and really mix it up well. The wide area is also good for drying…

-- After mixing up the dirt, allow it to dry in the hot sun for a few days, turning it up every day to get the moist stuff to the surface. This will expose it to heat and UV, which will help to destroy some of the bacteria and spores in the soil. I call it “solar pasteurization”, but I’m sure it has another name… many growers do this. Also, you want to load pots with dry soil, so that when you pack it, it doesn’t compress into a totally solid block.

-- Use pelletized dolomitic limestone specifically, because it dissolves quickly and provides instant basicity to the soil. The dolomitic part adds beneficial magnesium to the soil.
You can use powdered dolomite instead, but just adding extra limestone gravel won't give you the benefits. If you can’t find dolomite at all (hard to believe), mix in some horticultural lime powder.

-- Make sure any homemade compost is completely broken down... this means no more heat is being produced, it has no smell other than like dirt, etc. If you have the wherewithal to be making your own compost, then you should know this, already. wink.gif

-- I won't use hardwood ashes anymore for basifying the soil after dormancy... the fine dust clogs the soil surface up like concrete. I’d just try adding pickling lime (calcium hydroxide) to the post-dormancy water… add it until the water pH is around 9.5.

-- This is what the mix should look like when perfectly moistened and using arcyllite for the aerator. (These are closeup, mid, and far pics) :

Figure 1
user posted image

Notice that some of the round balls are left... now you know what to look for to crush them up. wink.gif


Notes on aerator materials

Do not use perlite or lava rock (the red stuff used for landscaping and gas barbecue grills) for the aerator material... neither of them work very well, but perlite is a little worse than lava rock. Don't bother with the perlite... it doesn't do much in this mix. You can try it if you like, but you'll find that it still allows compaction of this particular soil mix.

True pumice (white to dark grey, not red) works 2nd best, and the kiln fired clay is the best. I did experiments with all of these materials (and even more, actually) in Nan's mix, myself, just to find a perfect soil conditioner.

Why use aerator materials at all? Well, I offer you this snippet on the kiln-clay stuff...

This is not kitty litter or anything that will break down over time.  This is basically the same thing as terra cotta... which is why you can use crushed clay pots... also a commonly available item. 

I'll explain myself:

The original formula is damn near perfect for cacti.  The only problem is one of drainage after a year or two... the soil becomes compacted by settling slowly after each watering.  This eventually reduces drainage and the speed of transport of water and nutrients to the lower regions of the soil.

Nan's method for defeating this compaction is simple: Allow weeds to grow in the pots and their roots will break up the soil... when these weeds are pulled, the soil is "tilled" to some extent, aerating it.
This works very well, but being a perfectionist, I fear that leftover bits of weed roots will decompose, generating acidic conditions and bacterial/fungal vectors in pockets in the soil.  This is nitpicking, but like I said... I'm a perfectionist. 

The benefits of adding kiln-fired clay to the original Nan Dirt™ are as follows:

Long term- This material does not affect pH or soil chemistry at all... it is completely inert.  It does not float (perlite, pumice), sink (sand, gravel), or coalesce (coir, vermiculite) in any way.  It simply remains suspended as a natural part of the soil, indefinitely.  It improves the soil structure by adding microscopic pockets of air.  These bits provide aeration, and keep the soil "fluffy" for years and years.

Short term- When feeding, the tiny pockets fill with water and nutrients.  About half of the nutrient water absorbed is immediately allowed to flow down with gravity throughout the soil, filling the pockets of other particles.  This approximates allowing the roots to soak in a bubbly nutrient bath... sounds refreshing, doesn't it? 

It's like a pseudo-hydroponic setup.  (Indeed, this stuff is used as a hydroponic medium.)  So you get the best of both worlds by putting it into a good organic soil mix.  This is really what you want for any plant, but most other potted plants don't live as long as cacti. 

I'm not touting this as the only way to mix your soil, of course. This is just what I have found to work for me, as this stuff improves the structure of even the heaviest clay-filled (squishy clay... like you see in art class) soils. You can use this stuff, Nan's weeding method, or anything you want to aerate your soil... or even make up something entirely new! I only suggest that you study soil for a while before making any drastic changes to your mix... you wouldn't want to lose your precious cacti by something as silly as bad dirt!

I've figured out that as long as the soil drains entirely within an hour or so, it is "well-draining" enough for the roots to get the proper amount of air... you just don't want mud.

Also, as the roots grow, the soil aerates further, making it drain better as the cactus ages.

Remember the soil axiom:

Holds air like a balloon, holds water like a sponge, drains like a seive.

If the mix is right, it drains fairly quickly, but still holds lots of water... basically it should be a bunch of tiny sponges with air pockets in between them all. smile.gif


“OK, I’m ready to do this right! Oh… wait a minute… I can’t find any of this stuff at Wal-mart!!”

Don’t worry, I gotcha covered… wink.gif


Acid ID: If you're worried about identification of the mineral, bring some vinegar with you. Get a bit of the finest crushed (sandy) "limestone suspect", and pour some vinegar on it. Fizzing indicates limestone for your purposes. Watch it closely for bubbles... sometimes not much fizzing happens, due to the weakness of vinegar. Better yet, use a bit of the muriatic (Hydrochloric) from the hardware store! devil.gif

I have found some good stuff at a rock-crushing facility. They call it "B-1 grade". Apparently this is nearly the perfect size, from what I gather of Nan's descriptions:

Figure 2
user posted image

Chicken or pigeon grit is just fine as long as you make sure it is made of limestone (see acid trick above)! You can find this at feed stores... and feed stores are everywhere outside of major cities. wink.gif
Here are pictures of the limestone bird grit and its bag:

Thanks for the idea and pics, Major Buzz! wub.gif

Figure 3
user posted imageuser posted image

This stuff would be perfect for finer mixes, too.

Limestone is available; you may just have to search a bit, and probably settle for some stuff that isn’t perfect. Check feed stores, home improvement, local nurseries, quarries, and even places you wouldn't think to look, normally. You will find it. cool.gif

I've seen folks say to use oyster shell.

Here’s my advice: Do NOT use oyster shell in place of limestone gravel! It completely destroys any semblance of soil structure you may have had… the little plates orient themselves in the soil such that they form a dam, almost. I made some of this soil once, tested drainage, and the drainage got worse and worse with each watering… eventually the water would stand on top until it just absorbed into the sidewalls of the clay pot and evaporated! In addition, the sharp edges of these plates can shred your roots up if you ever repot.

Make it or buy it at garden stores. Sold in big bags for pretty cheap.

"Pelletized" Dolomitic limestone
Buy it at garden stores. Often it is found in the lawn care or landscaping section... near big bags of lime, rocks, mulch, etc. It may be called dolomite pellets, dolomite, pelletized limestone, or any other combination or exclusivity of these words. There will be tiny holes in the bag to allow gases to escape. Smell it. It smells very strongly of "base"... it's almost noxious and fumy up close.

Again, garden stores. By the way, this is topsoil, NOT potting soil… the two are very different.

Aerator materials
It's not easy to find good pumice, but you should try ordering it online... it's very light-weight, so shipping shouldn't be too bad. Look for white or gray color, and particles about 1/8” to 1/4" in size.

The kiln-fired clay bits can be found at good nurseries, hydroponic shops, and online. You want particles 1/8" to 1/4" in size. Schultz® Clay Soil Conditioner™ is what I use. Here is a picture of Schultz® Schultz Aquatic Plant Soil™ (the same material, marketed under a different name), courtesy of dephighance (Thanks, friend! wink.gif ) :
user posted image

You can easily just crush up some clay pots, sift out the finest dust, and use the 3-5mm bits, too. This is what our forefathers used for aerator material. cool.gif


Well, at some point we have to put this dirt into something. For some reason, people often have trouble with this… to these folks, I dedicate the next section…


Tip: You can place a rock over the hole in the pot while filling, but you must be sure that this rock does not completely (or even mostly) block the hole off… water still has to get through that thing. I use a cotton ball or two. This allows water to drain later, and helps keep root-eating bugs from getting into the bottom of the pot. Also:
One thing I do is put a square peice of fiberglass window screen at the bottom of the pot before filling it.It works great for allowing drainage,excluding pests,etc.

Thanks, Osprey! wink.gif

When loading soil into the pot, you are supposed to pack it down a bit with the palm of your hand or your fist… this doesn’t mean you should punch it or ram it down as hard as possible. Do not use your fingertips, either, as the small surface area will allow you to easily over-tamp the soil. You only want to pack the soil in the pot with about 5 to 10 pounds of pressure… this is about the weight of your arm.

The technique:

Fill the pot with 5 inches of dry soil.
Place your fist on this and allow the weight of your arm to rest on your fist.
Move your fist around in the pot, weighting it, until the soil is all fairly level.
Add another few inches of soil and repeat the process.
When you reach the wider areas of the pot, start using your palm instead of your fist.
Fill the pot up to about 1 inch below the rim with soil. If you added too much, don’t pack it down more… simply scoop some out.

For a cutting, just dig a 1 or 2 inch hole in the center of the soil. Fill the bottom of this hole with a little bit of the finer loose dirt (no pebbles), so there is a level squishy platform for the cactus butt. Press the cactus down on this soil, and then fill around the edges with more dirt, packing it hard between the ribs (you may have a small amount of damp soil on hand for this packing, so you can get a nice firm soil block to hold the cactus steady). You can use a garden stake or some large rocks around the cactus to hold it upright and steady while it roots… I really recommend this. There has been more than one occasion where a cactus just starting to root has been torn out of the dirt by strong winds or the random cat freak-out!

If you are potting a rooted cactus, you may want to enlist some help. Pack some soil in the bottom of the pot. One person should hold the cactus hovering, with the roots dangling in the pot, while the other gently fills around the roots, packing gently. When the pot is nearly full, gently lift it and thump it down on some soft ground a few times, while the other person holds a loose circle with his hands around the cactus… this will get the soil down in between the roots. If you are alone, just fill the pot with soil and pack as best you can around the roots… you may be able to whack the sides of the pot a bit while holding the cactus steady, too.

Side note: Definitely put the cacti in their own pots. Those things get incredibly heavy as they grow, and the soil itself weighs a ton (especially when wet!)… I had one pot with five in it (about 5 feet of total mass) and, because the pot needed to be large for all the separate plants, it weighed over 70 pounds... you may not think that's so bad, but just try lifting it while avoiding a thorough face-spiking! Large pots are not just heavy; they are very awkward to carry. Just put each cactus in a single pot, and put the pots close together. If any of them want friends, trust me, they'll just grow pups.

Looks good… but something is missing, don’t you agree? biggrin.gif

After potting, add a layer of smooth, lightly colored pea gravel or naturally white (not painted) aquarium gravel to the surface of the soil. This makes the planting more attractive, while providing many very practical benefits. Some folks use sand, and it has it's purposes, but I think rock looks nicer. tongue.gif Besides...

~ The rocks will reflect light away from the soil, keeping it nice and cool… just as the cacti want it. This reflected light bounces up onto the photosynthetic skin of the cactus, also. Sand does this, as well.

~ Rocks around the base of a cactus actually help to stave off base rot, as well. The reason for this is not fully understood… at least by me… but it really does seem to help. Again, sand helps too.

~ The stone will keep the soil from eroding... every time a raindrop or other sprinkling of water hits bare soil, it splatters mud up onto the cactus and out of the pots. Wind will also blow any dry surface soil away. Eventually, the topmost layer of roots can be exposed to the air, making them dry out and die back. The stones block the wind and reduce the impact of water directly on the soil. This diffusion also helps when liming the pots later… water washes the lime between the crevices of the stones, where it cannot be easily blown away by wind or splattered out by hard rain. Sand does not do this... in fact, sand is very messy when it comes to top-watering.

-- However, sand does one thing that pebbles do not: It creates and abrasive "wasteland" around the plants. Insects with soft underbellies cannot bear to walk across sand or lay eggs in it... the sand will scratch open their sensitive cuticles or the eggs they lay, and this will dehydrate them. You can use both sand and pebbles, and this will help protect against the egg-laying, but the insects themselves can simply use the pebbles as a bridge across the sand underneath.

But back to liming…
Q: Since I limed my cactus pots a lot of green algae has grown on top of the sand/rock dressing layer.  It looks kinda nasty so is there a way to get rid of it aside from continuously scraping off the top layer of sand? Any natural algae killers/deterrents that won't harm the cactus?

A: Yeah, diatomaceous earth causes the same phenomenon. I don't know how to get rid of it, but it really isn't going to hurt anything.  I think it looks kinda pretty... like moss-covered stones or something. 

I know a chlorine source (like bleach) would kill it, but that would probably hurt the cacti in some way.  In fact, anything that gets rid of the algae is probably gonna hurt the cacti... they are both plant-type organisms, after all.

A: (Bob Roberts) You could try a couple of things, like mulching or letting the plant go dry.

SAFER MOSS & ALGAE KILLER is another product that you could use sparingly, making sure to get the least amount on the plant or just spray it on (the soil surface).

GREEN SHIELD is another product that I'd recommend to have if you are reusing pots, wanting to clean a growing area, or make a volume of water for disinfecting.  It would also need to be used sparingly on plants.

Unless you have liverwort, pearlwort, or a large growth covering the top of your soil, then you are probably ok, save some aesthetic value.

A (Nan)  Algae growing in/on pots means you are nailing your optimum growth conditions pretty much dead on.


This leads us to the next section… (you know you love segways tongue.gif )

Soil Chemistry

I posted it a long time ago, and Nan's been saying it for years... pH is extremely important! It has to be right, or the cactus cannot absorb nutrients to grow, defend itself, or make goodies with.

The main thing about water (and nutrient) uptake in cacti roots is the pH... as long as the pH is right (slightly basic in this case), and the soil mix is well-draining, you can't over-water during the growing season.

Most problems can be solved by correcting pH for the specific type of plant you are growing. Petes and pedros (and most other cacti, in fact) need a pH around 7.5. Up to 8.5 is OK, but you should probably bring it down a notch with some Urea fertilizer if it gets this high.

Other plants like a slightly acid soil... that's the major reason most plants (and not cacti) do so well in store-bought potting soil (peat-based)... most folks think it's because the stuff is nice and fluffy, but that's only a small part of the picture.

Speaking of pictures, here’s a general chart of plant nutrient uptake according to pH:

Figure 2
user posted image

You want limestone gravel for long-term soil joy. The stone keeps the pH balance up due to its very slow dissolving. In fact, the only reason powdered lime is ever needed is because of drastic drops in pH... the stone would fix the problem on its own, given the time... we just don't want to wait that long, and we want to keep fertilizing.

Understand that drastic movement of the pH will slow or stunt the growth of a plant... the poor thing gets confused and dizzy from being able to absorb water/nutrients and then suddenly not being able to, back and forth, over and over... you get the idea. wacko.gif

Dolomite is less basic than regular limestone (it reacts slower, also), so it is actually better to use as a pH buffer than limestone. Unfortunately, you will be hard pressed to find bags of dolomite stone... it is almost always sold as a finely crushed powder. Again, dolomite is just calcium carbonate (limestone) mixed with magnesium carbonate. The calcium and carbonate ions disassociate slowly in water, and the magnesium ion comes off of its carbonate even slower... so the total speed of ionization is slower than with pure calcium carbonate.

Cacti will grow in neutral and acid soils, but not as well as slightly basic. It probably has to do with the fact that they are CAM plants (they transpire and gather the things they need to make food under cool night conditions, rather than during the day).

There's a great deal of discussion about soil composition for cacti amongst even professional nurserymen.

They all agree on two things:

1. That most cacti and succulents (with the exception of a few exotic tree-dwelling, and tropical species) grow poorly in acid soil.

2. That the soil must be well-drained.

They all have different methods of conquering the natural acidity that occurs as the humus or peat decomposes, and that which happens from nitrogen fixation (which simply pulls a bit of the "basicity" out of the soil).

-- Some just use only neutral materials like sand, perlite, crushed clay pots, etc.

-- Some use charcoal which pulls the excess ions out of the soil as the water leaches them toward the bottom of the pot.

-- Some recommend basifying the soil regularly with Lime and other basic agents.

-- Some use semi-permanent basic solids (like limestone) to keep a constant maintenance of the formed acids.

Most folks use a combination of two or more of these methods.
The strangest thing is that it seems the average educated grower of cacti never becomes aware of other methods... so he ends up just using what has always worked for him. There's no problem with that, unless this inadvertent "stubbornness" leads to the misunderstood death of any cacti.

You may have noticed in the chart (fig. 2) that it looks like a neutral soil would be more ideal… this is true, but only to a point. The reason a neutral soil isn't as good as a basic soil is because the pH is constantly being pulled down by forming acids... if their accumulation goes unchecked (and I mean even just a single day), you end up with an acid soil. Again, cacti are weird… even though it looks like a slightly acid soil is OK, it really isn’t. This is probably because of their odd method of metabolism (That CAM stuff we talked about).


I was going to include stuff about fertilizers here, but that kind of information deserves its own thread. If you’d like to know more about special soil mixes for rooting plants, there is plenty of information in the archives: Rooting San Pedro


In conclusion, I think an anecdote from Nan says it best…

What you get with my mix is long, long, long, term soil stability... With no severe pH drop after fertilizing. Pedro will grow well in lots of different types of soil... Peyote does not (much more rot prone and pH sensitive).

I am having bad base rot problems in a batch of cuttings a friend rooted up in some bagged soil mix which contain what looks like mulched pine bark... Base rot went over 10% when I started watering, and they were sickly yellow not taking up nutes. It took LOTS of lime to get the situation under control.

The thing about my soil mix... it's a sure thing. While one brand of commercial potting soil may be great for Pedro... How do you know without going to brand specific teks?  I worked out a mix that can be effectively made up by anyone and does the job right nice... But that is not the only way... Just the way that has worked the best for me over time

No, the recipe has not really changed since I first posted it... I experimented with generic mixes for a number of years before I hit one that met _my_ requirements.

But I will say again... peat (and now add pine to this list) based soil mixes are death to cactus roots and undersoil tissue.



Posted by: Osprey Aug 08 03, 07:15 AM GMT
One thing I do is put a square peice of fiberglass window screen at the bottom of the pot before filling it.It works great for allowing drainage,excluding pests,etc.

Posted by: MajorBuzz Aug 08 03, 10:00 AM GMT
Here is a picture of the bag my limestone came in. I found it at an animal feed store. 50 lbs was about six or seven bucks.

Posted by: Fungusmaximus Aug 08 03, 10:23 AM GMT
clap.gif clap.gif nerd.gif biggrin.gif

Great compilation of info, Ion wub.gif

Posted by: Nanook Aug 08 03, 12:10 PM GMT
I agree Ion, most excellent work wub.gif wub.gif wub.gif

Posted by: CockyMandrill Aug 08 03, 12:34 PM GMT
I found some of that shultz clay soil conditioner and it made the soil feel a lot better (I mixed up a new batch for five myrtillocactus's). It holds water so much better now and doesnt feel like cement after a heavy watering.

Posted by: dephighance Aug 08 03, 03:03 PM GMT
very nice, thankya

Posted by: Archaea Aug 08 03, 03:30 PM GMT
Good info.

I use a mix quite similar to nans soil but I have a question or two.

Why not use red lava rock? I though this was just large pumice.
What about black lavarock, it has a tougher texture than red?

I have used a few mixes over the years including coir based, peat based, fir bark based, and loam based mixes, all with various amendments and such. They all worked well though I lost some rot sensitive species to orange rot with peat based mixes.

Have you used Shultz Arcyllite (sp?) its a kiln fired ceramic media sold for both soil areation and as a mix for aquatic plants.


Posted by: John Doe Aug 08 03, 03:52 PM GMT
WOW ohmy.gif ION you Da man..holly shit thats alot of info...super job..thank you clap.gif clap.gif

Posted by: ion Aug 08 03, 11:56 PM GMT
They may have changed the name, arch... that sounds like exactly what I use. I acquired mine through a request to the Schultz company for replacement of some vermiculite... the bags pictured medium sized stuff and inside it was like sand. I was very polite in my request and they were very helpful... they sent gift certificates for the store where I bought them for the cost of the bags, plus a bag of their "new" professional series stuff, which happened to be this clay. I think they were doing a test market for it at the time. It's also possible that they simply market the stuff under two different names to different demographics. huh.gif

The stuff with the larger pores (red lava rock, and probably the black stuff if it used for the same things) seems to get clogged with soil and lose it's effectiveness. Also, the dust (sand) from it makes the soil become rubbery... when it's wet, the soil locks up (stops draining water) and has a springy texture, but not in a "light fluffy" way... it's very odd.

I'm glad it works so well for you, cocky... it sounds like you're having the same results I am. biggrin.gif

Buzz, the picture is going in. Thanks! wub.gif
Osprey, that's a fantastic idea! It's going in, also. wub.gif

Thanks for the lauding, everyone. Just remember that without your questions and input, this wouldn't have been so thorough. wink.gif


Posted by: Malformed Aug 09 03, 12:00 AM GMT
QUOTE (Osprey @ Aug 08 03, 07:15 AM GMT)
One thing I do is put a square peice of fiberglass window screen at the bottom of the pot before filling it.It works great for allowing drainage,excluding pests,etc.

i just fold over a piece of metal screen, and that works great for me.


Posted by: ion Aug 09 03, 12:25 AM GMT
Yep! Both should work well. The metal will rust out eventually, but it's likely no big deal.

The screen will allow better flow-through than cotton, but it won't protect as well against smaller bugs... so it just depends on what you're more worried about. My personal situation is tons of bugs! sad.gif


Posted by: Malformed Aug 09 03, 12:28 AM GMT
molds and etc here.

bugs are all over and hard to avoid no matter what is done.
so i figured having better airflow is better in the long run.

Posted by: Lophophophile Aug 09 03, 12:36 AM GMT
major- are most brands of pigeon grit minus grade limestone?
ion- excellent work once again wink.gif

Posted by: Malformed Aug 09 03, 06:21 AM GMT
just a picture...

Posted by: ion Aug 09 03, 02:23 PM GMT
That is limestone, mal, but it seems to be a bit too fine. The stuff I'm talking about is mostly rocks. The bag does have sandy material like that in it, but it's just from the rocks grinding together.

If you use that stuff as your only limestone (especially without an aerator material), the soil will turn to concrete rather quickly. That stuff is made for laying down over dirt to make a nice solid base that won't deform... so it's supposed to concrete up. :/

The rocks are used as a layer over top of that sandy material... this makes the whole area like that chunky conglomerate concrete you see with all the pebbles in it.

I'm considering removing that part about the Paver base, because it's really more confusing than helpful... and in light of the bird grit info, it seems like we now have a much more reliable source of the correct, washed limestone gravel. wink.gif

I'm gonna go buy some of that stuff as soon as I am able! biggrin.gif


Posted by: dephighance Aug 09 03, 04:05 PM GMT
i got that hydroton stuff. its like 1/2" diameter balls. these need to be crushed now?

Posted by: Nanook Aug 09 03, 04:12 PM GMT
I would think smaller fragments would work better wink.gif

Posted by: dephighance Aug 09 03, 04:19 PM GMT
gah. how does it make a difference though?

Posted by: Malformed Aug 09 03, 11:00 PM GMT
but it seems to be a bit too fine

i dont give a shit tongue.gif you guys make all this too compicated, i think the whole soil thing is over rated.

dirt and perlite has allways worked great for me in the past.
makes for a nice fluffy mix that doesnt compact.
good healthy root systems below and a healthy plant or cactus above.

im just going to use a little of the crushed limestone, some compost from the back yard, and toss the rest of the crushed limestone in the driveway.

Posted by: ion Aug 10 03, 01:01 AM GMT
Nobody knows anything about cacti... not even me. tongue.gif

Posted by: dephighance Aug 10 03, 01:12 AM GMT
its true. ion made it all up. its all part of he and nan's master plan to deceive the world into using soil thats too good for the cacti's own good.

Posted by: ion Aug 10 03, 01:44 AM GMT
Oh! Your question about the balls, deph...

Technically, the balls would work to some extent. There is a least one big problem with them, though: The size.

Large "pockets" within a soil matrix can lead to problems... this is why we want to mix the topsoil and compost together very well, breaking up any chunks. Chunks are equivalent to pockets...
Pockets are bad for 2 reasons:

1. They can easily become safe havens for a specific type of insect egg, fungus, bacteria, etc. Any conditions in the soil that these things would not like can be easily avoided by simply moving, germinating, or colonizing the soil pocket where it can live happily. Roots will eventually have to contact these pockets, making a direct vector for infection of the entire plant, or at least of that section of the roots.

2. Even if nothing bad lives in the pocket, the roots won't be as happy having to adjust to all these different miniature environments... especially if that pocket is deficient in something like minerals.

Smaller particles are best when it comes to particles that are porous (soil balls, clay balls, etc.). Roots are used to having slight variations in the soil matrix, and the smaller the particle is, the less "variation-like" the particle is.

Of course, if the soil was entirely comprised of these clay balls, then there would only be a variation of "ball" and "not ball". tongue.gif

Try hitting one with a hammer and see what kind of particles you get. You probably don't want a whole lot of dust, so you may need to wash the product after smashing it all to bits. I think one good whack with a hammer should net you some good size particles... a quarter of the size of one of those balls is what you are looking for.

If nothing else, you have a large bag of an excellent soil-less media to grow in. You could do some soil-less cactus pots and tell us how well it works. wink.gif


Posted by: Nanook Aug 10 03, 02:06 AM GMT
[email protected] laugh.gif

Of course we have to make it too complicated... If it were simple people would think it does not work wink.gif

Really tho... It's a normal process in tek development (which I have seen and done my fair share of)... People come up and want to know the BEST WAY to do things, and frequently that means some refinement on a simpler, perfectly adequate tek.

I would use some of that crushed stone, it looks like good stuff, just don't use it for 1/3 of the mix... Like 1/5 would probably work well, enough you have some stone well mixed in and visible, but not enough to seize the mix when it gets wet smile.gif

Posted by: ion Aug 10 03, 02:41 AM GMT
Alright Nan... lets see it. I need a picture and a source (one everyone can get to tongue.gif ) of the correct size stone. wink.gif

Put a ruler or coin in the pic so we can tell.

BTW, that pidgeon grit is about the same size as the clay particles I use. wink.gif


Posted by: entheopharm Aug 10 03, 03:06 AM GMT
wacko.gif OK ion ... but how about the smaller 4mm - 8mm Hydroton? Could that be used straight from the bag? It's the same price here as the regular and I'm all for not having to pull out the hammer to make soil. biggrin.gif

Posted by: ion Aug 10 03, 03:12 AM GMT
Yes! biggrin.gif

The smaller stuff sounds like the perfect size! 8mm is probably a bit large, but it should still be OK. Get me a picture, please. wub.gif

Posted by: ion Aug 10 03, 04:00 AM GMT
Some links for you folks:



Remember they are talking about pond plants... flourite is a non-porous mineral, in case you are wondering.
The CEC is still important for normal plants, though. wink.gif

If you cannot find the stuff at all (just look at the problems all those bonsai folks are having laugh.gif ), then just call this number: 1-314-298-2700

Ask them where to find it or if you can order it (or get a free sample biggrin.gif )

And, arch, I've figured it out:
Manufacturer's product name- Profile
Marketer's name- Schultz Clay Soil Conditioner
Material name- Arcillite
Material- Kiln-fired (porcelinized) clay aggregate (meaning it was re-hardened out of clay that was made from hard stone erosion)
Confusion factor- 9 out of 10 (second only to fertilizer names)


Posted by: Malformed Aug 10 03, 07:24 AM GMT
btw, i know the mix is suposed to be good and stuff... it just doesnt seem like that big of a deal to me.

ive allways thought of dirt as dirt, ive never been picky.

i have a idea of how dirt works, airation, drainage, etc.

anyway, the paver limestone i posted will work fine...

its got chunks and chips about the size of standard perlite. wink.gif biggrin.gif

Posted by: dephighance Aug 10 03, 03:47 PM GMT

still not done with this.

ive got hydroton on the left and http://www.schultz.com/proaqua.htm on the right. It seems to be the same kiln fired clay material. Is the size ok?

Posted by: ion Aug 10 03, 06:09 PM GMT
Mal, you apathetic little naysayer... laugh.gif

You probably saw many of these posts as they were originally written, and indeed there is a quote in there containing the general idea about all of this:

You can do whatever the hell you want. The cacti will probably live... at least for a while. But... this is the best way in my knowledge to make soil that lasts.

I won't extoll all the other the benefits, again. Those that know, know... those that don't, probably never will. So nyah! tongue.gif ~pbbbt!

The size is likely too large, deph... but hydroton is not something I experimented with in this soil (maybe I should have...), so I really can't tell you. All I know is the stuff about "pockets" like I mentioned in the previous thread. Sorry man... I just don't know. Like I said, though, it's worth it for the experiment! Try it out and report back to us! biggrin.gif

Thank you for the excellent picture, bro! I will use the right half (the arcyllite) for now, and if your test results are positive with the hydroton, I will include it, also. wub.gif

*edited to say: Oh yeah, the aquatic plant soil is the exact same stuff (arcyllite) marketed under a different name. wink.gif


Posted by: BoxedFarts Aug 10 03, 07:36 PM GMT
QUOTE (Nanook @ Aug 10 03, 07:06 AM GMT)
Of course we have to make it too complicated... If it were simple people would think it does not work wink.gif


Plain topsoil mixed with about 30-40% vermiculite is working fine for me, but then again, I've only been into the cactus for a little over a year now.

It's hysterical to me how obsessed you guys get with this! wacko.gif

Posted by: dephighance Aug 10 03, 10:08 PM GMT
yay. finally got the right shit. i'll experiment with hydroton a little maybe. kinda sucks that i went to the hydro shop and bought a 50lb bag of it
i tried crushing it up with a sledge hammer but thats just a mess. most of it gets into this fine lavarock-type powder. and the rest of it is too big, needs to be crushed more. its a pretty shitty situation. those pebbles are actually black inside. i thought it was clay all the way through.
It's hysterical to me how obsessed you guys get with this!

my plants are my children. i give them the most love and care as possible.

Posted by: ion Aug 11 03, 12:12 AM GMT
OK... I'll remove the hydroton bit from the work. Thanks for the heads up! Sorry it had to be considered a waste of cash for you... but it is better than perlite for properly humidifying mushies... and is a wonderful soil-less media for hydro. wink.gif

my plants are my children. i give them the most love and care as possible.

Damn straight, buddy! biggrin.gif

Ya know, boxy... I'm not gonna gloat, but I'll bet mine is bigger than yours... or faster getting up... or has better stamina... laugh.gif


Posted by: Samsara Aug 11 03, 12:37 AM GMT
Wow I like this thread..... biggrin.gif wub.gif wub.gif

Posted by: dephighance Aug 11 03, 06:49 AM GMT
im positive it will be used elsewhere in my garden. cool.gif

Posted by: CockyMandrill Aug 11 03, 07:18 AM GMT
dephighance, if your into mushroom growing you can make a killer automated setup with hydroton, Its in the archives somewhere if your interested, they call it the poor mans pod.

Posted by: dephighance Aug 11 03, 07:47 AM GMT
HMMM thanks for the heads up. i'll look for it

Posted by: BoxedFarts Aug 11 03, 10:25 AM GMT
QUOTE (ion @ Aug 11 03, 05:12 AM GMT)
Ya know, boxy... I'm not gonna gloat, but I'll bet mine is bigger than yours... or faster getting up... or has better stamina... laugh.gif



Im in the process of moving and I only have one of my pedros where Im staying now. Toad sent it to me after I won the Limmerick contest in January.

I measured it 2 days ago and it has grown 13" in 8 months. It's in plain dirt, no verm, I havent even fertilized it yet! I have access to a digicam now so I will post a pic of it in this thread in the next few days biggrin.gif

...and Professor Ion: it's not the size of the pedro, but the potency that counts wink.gif

Posted by: Nanook Aug 11 03, 12:22 PM GMT
No no... It's size and potency, you want both laugh.gif

And... Ion is not talking about dropping a plant in and and growing it in the soil for a year or two... Cacti generally stay potted up for years and years. I have had plants that went 20 years in the same soil, and the pots stayed pH stable and the cacti stayed happy with minimal care... In correct soil.

If you add powdered lime on occasion, you can make just about any soil work.

Posted by: dephighance Aug 11 03, 05:06 PM GMT
wow. you do realize that you have cacti older than i am

Posted by: Nanook Aug 11 03, 05:16 PM GMT
I have a number of mature specimens started from seed in 1976 wink.gif

If you start at your age, you can enjoy a lifetime cultivating these wonderful plants. I look back now and it was one of the most progressive decisions I made as a teenager... I got some Gottlieb publications from 20th Century Alchemist, wrote a letter to New Mexico Cactus Research, and started buying seeds and plants... And nobody was any the wiser as to the chemical roots of my new hobby.

Posted by: dephighance Aug 11 03, 05:58 PM GMT
heh. cool stuff man
whats the best kind of gravel to top off the pot with? im thinking limestone.

Posted by: Archaea Aug 11 03, 06:17 PM GMT
I like aquarium gravel for inside plants I bet limestone gravel would be just fine.

I wanted to mention that I sprouted cacti seeds in the Arcyllite about four years ago. As a germination medium it tended to be a bit dry but it worked fine. I found that when mixed with coir the pH was about 6.5 or so, just fine for sprouts but too acidic for establishment.

Posted by: ion Aug 12 03, 02:23 AM GMT
I measured it 2 days ago and it has grown 13" in 8 months. It's in plain dirt, no verm, I havent even fertilized it yet! I have access to a digicam now so I will post a pic of it in this thread in the next few days  biggrin.gif

Let's see some pics, now buddy! biggrin.gif

That catus will grow just great until the soil is leached of all nutrients that the cactus is able to take up... then you'll have to fertilize... then the soil will be acid and the cactus won't be able to take up the nutrients... then you'll have to lime... but as soon as you fertilize again, the pH will drop (you have no buffer)... and the routine starts again. By the way, liming after every feeding also wastes about half of your fertilizer... the stuff gets turned into insoluble salts, making it much harder for the cactus to absorb them. This does make for some good long-term minerals in the soil, but if most of them are long-term, then the cactus growth will also be long-term (meaning slow tongue.gif ).

It sounds like you have some very good topsoil in there, but just add some limestone chips to it to make it easier to manage. wink.gif

Oh... and 13" in 8 months means it's healthy, but not really healthy. tongue.gif
I'm currently getting at least 16-20" in a 6 month (and short summer) season on my established plants... devil.gif wacko.gif tongue.gif biggrin.gif laugh.gif


Posted by: BoxedFarts Aug 12 03, 01:51 PM GMT
Here it is tongue.gif

It was started in this pot with only about 4" of soil. It's getting transplanted into that mosaic terra cotta pot that is next to it later today (I just HAD to show off my handiwork wink.gif )

Of course, Im using my "Lazy and Frugal Mans Soil Mix" ™ devil.gif

Im thinking the reason for the skinny upper growth is because it was in a screened in patio until about a week ago. If it got full sunlight it would most definately be a few inches bigger.

I've NEVER had a complaint about the size of my Pedro cool.gif

Posted by: dephighance Aug 12 03, 03:08 PM GMT
its decent looking. nothing to drool over.
is there a benefit to using clay pots? i know they cant possibly drain as well having only 1 hole, where my black plastic pots have 5-6

Posted by: Nanook Aug 12 03, 03:12 PM GMT
Clay breathes wink.gif

Posted by: bluejay Aug 12 03, 04:55 PM GMT
Porous and lets water evaporate out thru it is also how to explain that it breathes...

Posted by: ion Aug 12 03, 04:58 PM GMT
Aww crap... forgot to add that part...

They are all worthy of drool, deph. drool.gif

But, yes... at least try the mix sometime, boxy. You'll see. wink.gif

Posted by: dephighance Aug 12 03, 05:20 PM GMT
has anyone tried using this mix on some Sceletium tortuosum ? would you recommend it?

Posted by: Nanook Aug 12 03, 05:37 PM GMT
I have yet to find a cacti that does not like it smile.gif

Posted by: dephighance Aug 12 03, 06:26 PM GMT
ah.. well Sceletium is a succulent..

Posted by: Nanook Aug 12 03, 06:59 PM GMT
Well try it and see... It can't be any worse for succlents than the peat based bagged stuff they sell wink.gif

Posted by: Malformed Aug 12 03, 07:15 PM GMT
i ended up doing a 1:1:2 mix
crushed limestone, perlite, dirt.

the more i dig into the bag of limestone the mire i like it, its not nearly as fine as it looks in the picture.
some is about the size of kitty litter.

after mixing it up and filling the pot, i decided i like it.
we will see how the cactus likes it. biggrin.gif

Posted by: CockyMandrill Aug 12 03, 07:25 PM GMT
It'll do fine, just make sure to get some nice food for it, peters all purpose is what most use.

Posted by: BoxedFarts Aug 12 03, 10:08 PM GMT
I'm really not trying to prove anyone wrong, but rather show/tell the results I got from my situation. I only had a very small screened in patio, so the size of my containers couldnt be large. I also didnt have a place to mix up a bunch of Nans soil mix.

I respect Nans long experience with cactus, and Im not trying to say his soil doesnt work. I just happened to get good results with 4" of plain soil in a tiny plastic pot in a screened in patio. So I guess my reason for coming out with this is that it's not as complicated as people here make it seem sometimes. You can do this without spending a lot of $$ or time. Just put the thing in some dirt and let it grow. In the long run, Nans mix is the way to go, I understand completely.

Once I move (and have a backyard) and my cactus collection expands I will try Nans mix. Fo shizzle biggrin.gif

Posted by: ion Aug 12 03, 10:12 PM GMT

That's good enough, mal... we won't ask any more of you. tongue.gif

This soil works extremely well for at least some succulents... my euphorbia lactea graft (on some other euphorbia stock) is doing beautifully in this dirt! biggrin.gif

Posted by: ion Aug 12 03, 10:22 PM GMT
I still love ya, boxy! biggrin.gif

It's all about their happiness, after all... laugh.gif

I don't care what anyone decides to grow in... as long as the cactus is healthy, I won't have to kill you. devil.gif

-ion, hitman for the Association Against CDA (Cactacea Domestic Abuse) cool.gif

Posted by: Nanook Aug 13 03, 12:21 AM GMT
laugh.gif laugh.gif laugh.gif

Posted by: CockyMandrill Aug 13 03, 08:26 AM GMT
You can do this without spending a lot of $$ or time.

Just wanted to say that all the ingredients in nans mix cost me like $8 total and I still have good amount left after making dirt for over 15 pots of varying size...so It ended up a lot cheaper than any premade soil mix, not as cheap as dirt but I think it looks and works better, and I also won't have to repot for years.

Posted by: BoxedFarts Aug 13 03, 08:50 AM GMT
Cool, CM.

Money isn't an issue right now, but a month ago I was digging through the cushions for loose change. I know there are more than a few here that are in a similar situation.

Geez, Im almost sorry I brought it up. If ya'll wore lipstick, Nans ass would look like a rainbow tongue.gif J/K!!!!

I'm just an audacious bastid, I mean no harm to your planet, really. biggrin.gif

Posted by: Toad Aug 13 03, 05:48 PM GMT
Just wanted to say that all the ingredients in nans mix cost me like $8 total

compost 1.50
soil 1.50
lime 1.00 @Quarry-5 gallon bucket
3.50 for 3- 5 gal. buckets full.

Nyah, Nyah tongue.gif

Posted by: dephighance Aug 13 03, 08:25 PM GMT
QUOTE (Toad @ Aug 13 03, 10:48 PM GMT)
Just wanted to say that all the ingredients in nans mix cost me like $8 total

compost 1.50
soil 1.50
lime 1.00 @Quarry-5 gallon bucket
3.50 for 3- 5 gal. buckets full.

Nyah, Nyah tongue.gif

No kiln fired clay? No dolomite limestone? ohmy.gif

Posted by: ion Aug 28 03, 02:37 PM GMT
I've updated some pics and info. wub.gif

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