Al's gritty mix questions

kwie2011(8a/8b W. OR)August 12, 2014

I have a few questions about Al's gritty mix that haven't been answered in the copious amount of information I've read (or my fried brain missed it).

1. What is the purpose of each of the 3 components: Turface, granite, bark? Ie, why not just plant in Gran-I-Grit or Turface alone?

2. Does the #2 Gran-I-Grit need to be screened also, or is it close enough to the right size already? I tested a bit, and I was surprised to see about half fit through a 1/8" sheet of hardware cloth.

3. How do you know when your plants need water in this stuff? I've always been able to dig a finger in or feel the weight before. That technique doesn't work with gritty mix.

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The finger technique does still work, I rub the finger I used against my thumb and you CAN feel if there's moisture. Also you can get wooden dowels at any hardware store REALLY cheap. That works too. Place it against the inside of your arm or cheek if it feels cool there's moisture. You could just grow in the grit and turface it depends on what works best for you and watering, turface holds the most water where grit I believe doesn't hold any (or next to nothing) the bark is kind of to have some organic in it, it does hold water also. For me, I can't tell by the color of the bark (light or dark) if it's going to need watering. (I still check anyway with my finger or the dowel to see if the middle or the bottom is still wet. The grit is to have consistent size particles from what I understand to help with the drainage and because the grit and turface are the same size the mix holds that drainage quality. Am I making sense? I think it also helps with the cost because the turface and bark (I used repti bark) were the most expensive part) so to me I look at it as a filler for drainage because it doesn't hold water yet helps retain the particle size. I heard others exclude the bark, from what I understand, it has little nutrition factor but kind of helps you get over the initial hump when you first repot and can't fertilize right away. I'm sure someone else will DEFINATLEY chime in on this one to help (especially if I didn't explain it right lol) so please if I've explained poorly, I am sorry :)

    Bookmark   August 12, 2014 at 10:09PM
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I meant to say I CAN tell by the color of the bark usually (but I still use my finger or dowel just to make sure)

    Bookmark   August 12, 2014 at 10:12PM
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dellis326 (Danny)

I don't use gritty mix but as I understand it's use;

(1) That someone else will need to answer that. But I don't think Turface or granite grit wouldn't hold any useful amount moisture alone.

(2) the concept of screening the components is to remove all the fines so that air can get to the roots and provide oxygen.

(3) You water every few days to a week. You just assume it can use the water because the mix holds little moisture and any water that would otherwise be considered "too much" will run off.

Semi-Hydro just seems easier to me and most plants will do fine in it.

    Bookmark   August 12, 2014 at 10:15PM
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kwie2011(8a/8b W. OR)

Thanks, guys. It isn't possible that you two are the only ones on the site with opinions on this. It seems like half the people here use it or recommend it, so they must have opinions, right?

Hmmm. I thank you both for speaking up, but I hoped more people would. Where's Al? Heeeeeeyy Aaaaaaalllll!

LilBit, are you growing tropicals in gritty mix, or just succulents?

How exactly are you using a dowel? You're sticking it in every few days to see if it comes up wet? How long does it have to be in the mix to get damp enough to retain a water mark? I have about 50 plants. Am I going to need 25 dowels (pieces) every time I water?

Any idea what plants DON'T grow well in gritty mix? Al also has a recipe for 5:1:1, which is very different, so there must be some that don't like the gritty mix.

    Bookmark   August 13, 2014 at 3:20PM
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Suzi AKA DesertDance Zone 9b

I will say, a few years ago, Al created a gritty mix especially for the hot desert, which is where I was.

That stuff drained well, remained damp and nothing died that was ever planted in it.

Now we have moved to acreage, and the only things in pots are those waiting to be planted in ground. I miss the gritty mix!

I worry that what we have isn't quite up to snuff. The ground is pure decomposed granite. We use compost and mulch, but... is that enough?

    Bookmark   August 13, 2014 at 3:26PM
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tapla (mid-MI z5b-6a)

Hi, Kwie. We had a significant storm here & I've been w/o net service for a couple of days, or I'd have responded sooner. Come to find out, though, the cause was a bad modem & not the storm.

Hint - place a higher value on the opinions of those that have actually USED the gritty mix to implement the concept that the more water held inside of soil particles and the less water held between particles, the better are your plants' chances to realize their genetic potential. Many growers simply announce they really don't understand the concept when they say that the gritty mix doesn't hold enough water. ..... and I'm not singling any one person out - only noting that because the gritty mix is so widely adjustable for water retention by varying the ratio of screened Turface:grit, it can be made so it holds a significant amount of water, yet no (or very little) perched water; so if it doesn't hold enough water at a 1:1:1 (or 3:3:3) bark:Turface:grit ratio, simply change to 3:4:2 bark:Turface:grit for more water retention.

The bark's water holding ability is somewhere near the average of equal volumes of Turface + grit, so it is a good light weight and inexpensive way to bulk up the soil, provide a little nutrition, and ease the apprehension of those who are uneasy about growing in an entirely inorganic mix. The idea that only soils that are 'rich and black' can provide a healthy home for roots is deeply ingrained, even if completely false. Structure is the most important aspect of soil function, not its ability to feed the plant. Nutrition is monkey easy and on the grower's shoulders - or should be.

1) The gritty mix uses a limited volume of organic matter to ensure the soil cannot collapse. If you used only 2 components, like bark and Turface, you would have either too much water retention (for most apps), or too large of an organic fraction, which could clog the soil over time as the bark breaks down. You CAN use only Turface and grit if you like, but I would suggest you start at a 2:1 ratio of grit:screened Turface. Foliage-Pro 9-3-6 has everything in it that plants need, and super-simplifies the growing experience - makes it really hard to go wrong.

2) Grower size Gran-I-Grit and #2 cherrystone come prescreened, but I still give them a quick screen over insect screen to rid the grit of the dust ..... or I use a kitchen strainer and rinse it off. It's not much extra effort, and prevents any sludge build-up on the pot bottom. I also rinse until the water runs clear out of the drain hole when I first plant in fresh soil, for the same reason. Everything but the dust gets used.

Screening is important because particles of roughly the same size don't compact. Think of a jar of marbles and a jar of BBs. Mix the BBs with the marbles and a good part of your air apace disappears. Mix in sand, and almost all of it disappears and the soil starts to hold perched water, which is the limiting factor the gritty mix is aimed at eliminating.

3) The finger test works if your pot diameter is large enough and the planting is established. If you give a little thought to your watering intervals, it's hard to over-water anything in the gritty mix. I water my succulents on the same schedule as all my other plants and never have a problem. I rarely 'test' to see if the soil is moist - after a little while, you'll develop a feel for when plants need watering. You only need 1 skewer or dowel if you use that method until you get a feel for things. Just wipe it dry with a paper towel or rag between tests.

The reason many of us use 2 different soils is more a matter of $, effort (the 5:1:1 is easy, the gritty is more effort but a better end product), and how long a plant will go between repots. All my veggies and garden display containers that go on the compost pile in Oct get 5:1:1. All my long term plantings (2 or more growth cycles in the same soil) get the gritty mix. A few fast growers that would normally go in the gritty mix (hibiscus, datura, brugmansia, ....) also go in the 5:1:1 because root growth is so vigorous they need repotting every year if you want the most out of them.

Anything else you can think of?


    Bookmark   August 13, 2014 at 4:57PM
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kwie2011(8a/8b W. OR)

You are very thorough, Al. Thank you. I think you've covered everything, but if I have more questions as my little project progresses, I will holler. Thanks very much for your help.

    Bookmark   August 13, 2014 at 11:57PM
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Thank you Al I learned ANOTHER VALUABLE lesson from you. I understand better myself. Thank you for chiming in. I'm SOOOO SORRY I didn't explain everything correctly. I honestly thought the grit didn't hold water. That it was there to help with drainage and expense. SOOO SORRY. I LOVE ALL your knowledge and eagerness to help us newbies and your mixes. I have seen in a VERY short time what an improvement it has made in my plants and I guess when I know someone can benefit from it I try to help. So sorry once again that I didn't explain everything right.

    Bookmark   August 14, 2014 at 12:40AM
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Kiwie for your question I've repotted all my succulents, philodendron, pot his, purple passion, rex bagonia, (and a few others) in it. They all are doing great some of my foliage plants I have to water a little more than the rest but that's fine with me I had made a large batch and because I mostly grow mostly succulents I didn't change anything. I used the 1-1-1. I don't think I'll change it up later on unless I move some where where the climate significantly changes for me lol. I love caring for my plants, it gets my mind off the "EVERY DAY CAOS" so I enjoy watering time :) when I first repotted I checked them ALOT only because I was unsure how long the mix would go between waterings but I've gotten so I can pretty much look at it and know when I need to water you'll see when you use it. I still check sometimes (because I'm OCD) and still worry I might be watering to soon but I think that would be very hard to do. Hope I helped some. After MASTER TEACHER Al,
I can't compare! :)

    Bookmark   August 14, 2014 at 1:00AM
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Loveplants2 8b Virginia Beach, Virginia

Hello Everyone!!!

Al explained all of the reasons that the OP asked.. Why it is needed and why size matters... It does have a purpose and he always explains it better than me!! ;-)

I just wanted to chime in and say that I have been a follower of these mixes and the great science that backs up why this mix works for our trees..

It all starts with the roots and proper aeration that helps the roots get the best start so they will be the healthiest starting point for any plant or tree. Once you understand the science and why this works it will become so much easier. When your roots are happy then the rest of the tree will show you and gift you with growth, foliage and a great overall vitality in the houseplant

I have been using this method for many years and I am here to let you all know that you are asking the right questions and I can see that you are in good company... .

I grow a lot of tropicals that are hard to grow in many areas, but since I learned how to properly make my soil and even adjust to my needs as far as water retention, I have never seen my trees flourish as they have year after year. I can control how much it can retain or make sure it drains faster if needed. Once you get the basics, you can adjust to you trees ( varieties) needs.

This is the best as far as I am concerned and now that I understand what my plants and trees need to grow to their full potential, I don't worry at all about watering or fertilizing. It all becomes easy and I promise the effort you put In to making this mix and understanding why and how it works, you will be rewarded as well.

Always ask question.. This is how we all started and how we share information. We all were beginners at one time and we all remember that wonderful feeling and the excitement in growing and finally understanding what is being taught. The light finally glows.. Then your heart will explode with joy because you had a major hand In what you did for your trees.

It doesn't get any better than this.. Healthy trees, blooms, veggies galore!!,

Many here do use the Gritty mix as well as the 5-1-1 and Im Sure others will come say a few things as well...

I will never go back to a bagged soil. It's easier for me once I have all of the ingredients handy to make it as needed or I will make it and store it in covered five gallon buckets from Lowes.

When you start with healthy roots that receive that proper aeration and then add the sunshine, proper watering, fertilization .and climate control for certain trees... You will have the perfect recipe for a beautiful growing season.

When I first started checking for water.. I used the wooden skewers. It's better than the finger because you can get in deeper to the container. Once you get the feeling of how to water, most of us can just lift the container or look at a tree and know the watering routine it needs. It will come to you all..

It is so much fun!! Enjoy!!,

Ask questions...

Oh.. I grow Plumeria and adeniums, some other trees and exotic plants...
They are in the Gritty or the 5-1-1

Have a wonderful night!!!

Here is a picture on one that just bloomed last week...


    Bookmark   August 14, 2014 at 1:28AM
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tapla (mid-MI z5b-6a)

Hi, Laura - always good to see you and your lovely plants, and I always enjoy your POV.

LB - I didn't notice anything you said that wasn't correct. The grit fraction really doesn't hold water, except a very thin film on it's surface, like all soil particles do, and a little at the interface between soil particles. Even tho a jar of marbles wouldn't hold water in the spaces between the marbles, they still hold a little water where the particles touch and water vapor in the large pores between the marbles. Plants don't drink water, they take it up molecule by molecule from the microscopically thin coating of water on the surface of particles and the water vapor found in larger air spaces between particles. Large reservoirs of liquid water are worse than useless because they deprive the plant of the O2 needed to drive absorption. Compounding the limitation is the fact that if the plant isn't adequately absorbing water, it's also not absorbing the volume of nutrients it normally would if the process was unimpeded by a lack of oxygen, so it suffers a multiple whammy.


    Bookmark   August 14, 2014 at 9:10AM
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drew51 SE MI Z5b/6a

I find the mix way to heavy for my bigger plants. I ended up using the grit under my landscape stones to keep them level. That worked good! I made a mix with cork instead of grit. Also turface has much too small pores to be very useful to release water to roots, so I use diatomaceous earth instead. Pore size can be accessed by plant roots, unlike turface. It holds more water too. Also makes oxygen available when dry. So this mix was very light and worked extremely well. But to each his own. If it's not broke don't fix it.
Cork is very expensive and not practical, but I has specific needs, so bought enough to make one batch, enough to handle some larger cacti I had.
It's also difficult to find horticultural cork. But some bonsai places have it.

    Bookmark   August 14, 2014 at 11:32AM
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tapla (mid-MI z5b-6a)

Hmmmm - as of last Dec, Drew hadn't even tried the gritty mix, so I'm unsure how he knows it's "too heavy". The idea that plants can't access the water held in Turface's open-cell pores has no merit - and won't hold up under the mildest scrutiny. DE is no substitute for Turface unless it's calcined (fired at a temperature high enough to ensure its structural stability) - a critical detail; and Calcined DE has always been an adequate substitute for Turface. ANY soil ingredient tends to increase available O2 when the soil is dry. That's a lot of very vague or simply erroneous information offered in attempt to shed unfavorable light on the gritty mix that isn't warranted, and it's something he habitually does. That's just some honest contextual information for the record.

In 25 years of haunting bonsai shops, nurseries, online stores, and conventions, I've never seen cork available or advertised as a potential fraction of a bonsai medium or any other medium. I'm not saying it's not appropriate, just that if people think pine or fir bark in an appropriate size is difficult to find, I can only imagine what it would be like trying to find cork in an appropriate size.

The basic recipe for gritty mix uses ingredients that facilitate establishing goals centered on making it easy for the grower to consistently provide a healthy home for roots, with a minimum of limitations inherent in other media that hold significant volumes of perched water. There are a number of ways to get close to that goal, some good, some not so good, and some altogether impractical. One clear reason cork is not advertised for use as a soil component is because oak bark is rich in phenolic bio-compounds (tannins) that are known to be directly allelopathic (inhibit the growth of other plants) and or active as a synergist. IOW, I would caution anyone against blindly leaping toward using cork as any significant fraction of a container medium.

As far as the weight of the gritty mix: at soil capacity it's not that much heavier (maybe 25%) than water retentive soils like MG, the reason being MG and other soils built around large fractions of fine ingredients hold a lot of excess water in pores between soil particles, while the gritty mix holds air in its larger pores. Once you change the focus from what's best for the plant to what's best for the grower, it shouldn't be a surprise if something is lost in the change of focus.


    Bookmark   August 17, 2014 at 9:58PM
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When it comes down to it, the proof is in the pudding, so it's best to trust the ones with the pudding.

All I can say is that no matter what I (or you) may read from those who argue against gritty mix, again, the proof is in the pudding. Since using it, I've had nothing but great success, and during repots, I marvel over how healthy the feeder roots are, and how easy it is to repot, something I've never experienced with bagged mix. Granted, there's no argument in this thread in favor of bagged mixes, but there is one against Turface. I have used straight turface and grit pretty much from the get go, and if Turface doesn't release water to plant roots, surely my plants would have died from drought stress right? Not so. The turface, being the moisture holding component of the mix, seems to be doing quite a good job at releasing moisture to the roots.


    Bookmark   August 18, 2014 at 6:50PM
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I've been growing in the gritty mix for years and the only problem I have ever incurred was my own fault..

I either was too heavy with the watering can, didn't sift properly, used the wrong size ingredients, made a variation of it, didn't fertilize properly, or under watered...This you learn, but it takes TIME...Yes, for me it tooks months and months...For others, they learn over night..All of this, how to use the gritty 1.1.1 mix, support and positive experiences is all here for the taking...
I had to learn patience and understanding...I was willing to give it a chance before I criticized it. Some won't.

I can tell you too that every plant that was on it's death bed for whatever reason, especially in poor water retentive soil mixes, has thrived as soon as its roots were set into the 1.1.1 or 5.1.1 mixes ...I have saved a many plants because of the 1.1.1 mix and my others continue to thrive after all these years...I have seen roots once in disarray and half dead heal and grow very rapidly in it.

The only ones that don't have success with it are the ones that have only themselves to blame..
And then it turn they criticize the mixes or the one that introduced them, instead of themselves because they could never get it right..
It now becomes what's best for the grower to overcome their ability to use these mixes and let them work as they should, and not for that of their plants..

I am forever grateful!

This post was edited by meyermike_1micha on Mon, Aug 18, 14 at 21:23

    Bookmark   August 18, 2014 at 7:12PM
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