Custom Cactus Soil Mix

Discuss repotting, soil, lighting, fertilizing, watering, etc. in this category.
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Martha15
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Re: Custom Cactus Soil Mix

Post by Martha15 »

Thanks for your article! Since joining this forum I'm learning so much, thank you all for sharing.
-Martha
Grow & Be Happy!
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CACTUSCANADA
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Re: Daiv, help please and all others as well.......

Post by CACTUSCANADA »

Di wrote: Sat Aug 01, 2009 5:18 am I have more cacti to plant. As I have already killed some of my succulents, I don't want to lose more. The cacti I have seem to be happy in the soil mix I have them in which is a rich cactus soil mix and a not rich soil mix. Since joining this forum, I have been adding perlite. Since reading more posts, the ones I have recently potted have even more perlite added. I didn't add as much for the first batch. I don't want to repot the ones with less because they seem happy. Or maybe I should. Had I kept a record, I would know which have more and which have less. I read your soil mix and you mention Coir.

There are two different ones at the store across the street from me.

Here are the descriptions: Organic soil alternative

Made from 100% coconut coir

100% organic and biodegradable

Just add water - block expands to 0.5 cu. ft.

Saves water - absorbs 50% more than regular soil

Excellent for all indoor & outdoor containers

The other: Water saving coir substitute for peat moss; retains moisture, aerates and conditions soil

100% organic, environmentally friendly, renewable resource

Lasts longer than wood

Retains natural colour longer

Suppresses weeds

Expands in size equal to 2 cu. ft. bag when hydrated

One block covers 12 sq. ft.

Exclusive to Canadian Tire

Should I buy one of these and add it to my soup pot of soil?

I have 10 cacti to pot this weekend and if I should add a bunch of Coir, I will.

I figure the best I can do it a little of the rich soil, way more of the less rich, lots of perlite and some coir.

Does this sound OK?

Any suggestions would be much appreciated.

Thanks
Di
Careful with coir, its recommended to properly rinse it prior to use as it can contain high levels of salinity.
:D
kuni1234567
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Re: Custom Cactus Soil Mix

Post by kuni1234567 »

I try to grow cactus in soils were they grow in nature. I think that every cactus grower has different growing conditions and no soil mixture works for everything. I sometimes mix organic free soil and see what happens. I have some cactus growing in pure pumice, no organics and many other combinations. I also visit Southern California deserts and have dug up soil and planted some cactus without any problems. I think trying difficult soil mixtures is a good idea and through experience there are many cactus that I cannot grow successfully.
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jp29
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Re: Custom Cactus Soil Mix

Post by jp29 »

I have always experimented with soil mixes - I think I have used about every one that has been devised during my growing lifetime - and I have found all those that were of coarse and gritty texture, thus providing excellent drainage and root aeration, consistently produced healthy and robust plants. In consequence I have always used very porous, well aerated, soil mixes for cultivating potted cacti.”

During my C&S growing lifetime I have cultivated my plants - sometimes in the greenhouse, sometimes outdoors depending on the location - in the following locales (approx. years):

Northern England (Lancashire) 1939 to 1950

Southern Texas 1950 to 1960

Japan (Honshu north of Tokyo) 1960 to 1963 (sporadically)

Southern California (Mohave Desert, Victorville) 1963 to 1968

Central Florida (Tampa) 1968 to 1970

Southern Arizona (Tucson) 1970 to 2018 (present)

I have always adjusted my primary soil mixes to match the growing environment/climate in accordance with the overall criterion I outline above. That is what you have to do. The soil mixes I used while growing in higher humidity environments - Northern England, Japan, Florida and to some extent Southern Texas, emphasized quick draining and mineral composition while those I used in Southern California and now here in Southern Arizona require some water retentive components (I use coconut coir for the vegetative component) because of the relentless and ferocious summer sun and extremely high temperatures. But those are just generalities - each grower has to experiment in order to meet the needs of their plants according to their environment and the availability of soil constituents.

.......... just my take on things, nothing profound or new.
James
My cactus cultivation pages:
https://jp29.org/cactuscult.htm Image
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jp29
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Re: Custom Cactus Soil Mix

Post by jp29 »

kuni1234567 wrote: Thu Mar 15, 2018 3:16 am I try to grow cactus in soils were they grow in nature. I think that every cactus grower has different growing conditions and no soil mixture works for everything. I sometimes mix organic free soil and see what happens. I have some cactus growing in pure pumice, no organics and many other combinations. I also visit Southern California deserts and have dug up soil and planted some cactus without any problems. I think trying difficult soil mixtures is a good idea and through experience there are many cactus that I cannot grow successfully.
I have had mixed results doing that kuni. Please visit my web page at ..........

http://jp29.org/00ds.htm

.......... for one of my adventures. The problem is that, at least in container cultivation, we are growing our arid land plants in a very artificial environment and the growing media (soil) we use often performs quite differently than it does in habitat - in the absence of the buffering effect of land mass, water percolates differently in the confines of a pot. Many years ago I experimented using just the soil from habitat in growing some Ariocarpus fissuratus in pots. They survived, but they didn’t grow as well as those I was growing in my regular soil mix. Of course, I may not have employing the correct watering technique. I have used other habitat soils for growing cacti on occasion, with about the same experience.
James
My cactus cultivation pages:
https://jp29.org/cactuscult.htm Image
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Daedalux
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Re: Custom Cactus Soil Mix

Post by Daedalux »

I've been putting my desert fellas in pure pumice and they seem to be going well, the more jungly ones I'm getting them in a 50/50 mix with some cactus mix and pumice/perlite. They all seem fine so far!
Cactifan800
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Location: NSW Australia

Re: Custom Cactus Soil Mix

Post by Cactifan800 »

I'm wonder what you guys think of my simple mix.
I'm from Sydney, Australia. I use 2 parts regular potting mix and 1 part washed river sand.

The problem with pumice and other types of inorganic materials is that they are extremely expensive where I live.
A bag of 25L pumice is over $30 and a few of my golden barrels, tricocereus, stenocereus and pilocereus are in 500mm plastic pots. They would require two bags of pumice and that is just not feasible.
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greenknight
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Re: Custom Cactus Soil Mix

Post by greenknight »

If it's coarse sand, okay, you just don't want to use fine sand. I would increase the proportion of inorganic material to al least half. How about cat litter or oil dry? It has to be a type that remains hard when it gets wet, not clumping litter.
Spence :mrgreen:
Cactifan800
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Re: Custom Cactus Soil Mix

Post by Cactifan800 »

Yes I'm using very coarse sand, as for kitty litter, is their a particular type I need to look out for?

The kitty litter sold in supermarkets look like hard crystals.

My mix do vary from cactus to cactus, I add more sand plus leftover aquarium gravel to my mix for rot prone cati. While others like opuntia and austrocylindropuntia, I grow them in straight up potting mix and they still require a lot of watering, up to twice per week in summer.
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greenknight
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Re: Custom Cactus Soil Mix

Post by greenknight »

Hard crystals? I don't know what that might be, the kind I was thinking of is high-fired clay litter - non-clumping, unscented, without any additives. Daiv's article, linked it the first post of this thread, lists other alternatives (including aquarium gravel).

Yes, Opuntias are not fussy about soil, and do like a little more moisture than a lot of cacti. As long as you're adding extra drainage material to your basic mix for those plants that need it, you should do fine. Sounds like you have a pretty good grasp on what cacti require.
Spence :mrgreen:
Cactifan800
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Location: NSW Australia

Re: Custom Cactus Soil Mix

Post by Cactifan800 »

Thank you spence, i will check out your recommendations.
As for opuntias, most of them are classified weeds in Australia.
Nuseries here are banned from selling them.
So I buy mine from sunday markets or facebook marketplace.
victoryboxer
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Re: Custom Cactus Soil Mix

Post by victoryboxer »

So I'm stumbling into the thread because I'm SO confused. I have cacti and succulents in Charleston, SC growing in pots on my porch. I have repotted them once now and I think I have to do that again 😭 I used 50% potting soil 25% pumice soil and 25% fine sand.

Now I'm told I did the wrong sand.... Sooo I was thinking about repotting them with 50% potting soil and 50% pumice soil? BUT should I do the chicken grit? I found it on Amazon for $7 (it's a "with probiotics" kind.

I'm just confused and don't want my new babies to die!
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Steve Johnson
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Re: Custom Cactus Soil Mix

Post by Steve Johnson »

victoryboxer wrote: Sun Jul 14, 2019 4:29 pm So I'm stumbling into the thread because I'm SO confused. I have cacti and succulents in Charleston, SC growing in pots on my porch. I have repotted them once now and I think I have to do that again 😭 I used 50% potting soil 25% pumice soil and 25% fine sand.

Now I'm told I did the wrong sand.... Sooo I was thinking about repotting them with 50% potting soil and 50% pumice soil? BUT should I do the chicken grit? I found it on Amazon for $7 (it's a "with probiotics" kind.

I'm just confused and don't want my new babies to die!
I know what you're going through, and it's not unusual for beginners to get confused by advice coming from different sources. Hopefully I can unconfuse you a little bit...

There are only 2 basic ingredients people need for cactus and succulent mixes -- soil and rocks. The proportions of both will depend because cacti and succulents have different growing requirements. Almost all of my experience is with growing desert cacti, so we'll start with that.

Pumice is the perfect mineral gravel because it has the unique combination of open porosity and good moisture retention. (By the way, there's no such thing as "pumice soil".) Unless you live in a desert-type climate (which you don't -- Charleston has a humid subtropical climate), you should do well growing desert cacti with straight pumice or a pumice-granite gravel mix. If your chicken grit is crushed granite, you can use that. I grow the vast majority of my cacti in a 60/40 pumice-to-granite gravel mix, but the granite is there primarily to make my pots heavier so they don't tip over in the wind. If you don't have problems with windy conditions, you may not need the chicken grit at all. Some species of desert cactus (Tephrocactus, for example) have very fine root systems that won't be supported well in a soil-less mix, so a 50/50 pumice-to-soil mix is better for them. So-called "desert tropicals" (Melocactus, Discocactus, etc. I think Echinopsis may also apply) need some soil in the mix too, but I tend to go light on the soil for Melos and Discos. Cacti grown soil-less require being fertilized pretty much every time they're watered in the growing season. My fert of choice is Dyna Gro All Pro 7-7-7, although it's expensive, so maybe not the best choice since you have such a small collection. Dyna Gro Orchid Pro 7-8-6 is the next best choice, and you can find it in small (and more cost-effective) quantities on eBay. Dilute 1/2 teaspoon of the liquid concentrate in a gallon of water.

My experience with succulents is confined to a Haworthia attenuata in the collection, and I'm doing really well with it in a 50/50 pumice-to-soil mix. Intuitively speaking, I think that should be fine for most or all succulents, but I'll defer to members who have more experience with them. Unlike soil-less mixes, soil in the mix will retain nutrients from ferts, so you won't need to fertilize succulents nearly as often.

I've been thinking about what you might want to do with regard to potting soils. Since we know that Miracle Gro is right out, the only guidance I can give you is what to look for and what to avoid with other commercial potting soils. Something you should absolutely avoid is anything containing peat -- takes too long to wet, and once it gets wet, it takes forever to dry out. Aloinopsis was spot-on about telling you to avoid sand, so that's another red flag if you see it as an ingredient listed in a commercial potting soil. If you can find something that's just dirt and tree bark, pick out the big chunks and throw them away, then you may have an acceptable soil you can go with for your mix(es).

One last thing I'll mention. I'm a firm believer in gravel top dressings for 2 reasons -- first, they add a decorative touch. And second, they'll keep all the floaty stuff in the mix from getting all over your plants whenever you water. I can get all kinds of attractive top dressings at local cactus nurseries, although that may not be an option for you. If it isn't, a good layer of granite gravel on top will do the job. Oh yeah, almost forgot -- rinse your mineral gravels thoroughly before you put them into your mixes. Too much mineral dust is no bueno (as I found out from hard experience), so take the time to do this.
If you just want photos without all the blather, please visit my Flickr gallery.
My location: Los Angeles, CA (Zone 10b)
victoryboxer
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Re: Custom Cactus Soil Mix

Post by victoryboxer »

Steve Johnson wrote: Sun Jul 14, 2019 8:45 pm
victoryboxer wrote: Sun Jul 14, 2019 4:29 pm So I'm stumbling into the thread because I'm SO confused. I have cacti and succulents in Charleston, SC growing in pots on my porch. I have repotted them once now and I think I have to do that again 😭 I used 50% potting soil 25% pumice soil and 25% fine sand.

Now I'm told I did the wrong sand.... Sooo I was thinking about repotting them with 50% potting soil and 50% pumice soil? BUT should I do the chicken grit? I found it on Amazon for $7 (it's a "with probiotics" kind.

I'm just confused and don't want my new babies to die!
I know what you're going through, and it's not unusual for beginners to get confused by advice coming from different sources. Hopefully I can unconfuse you a little bit...

There are only 2 basic ingredients people need for cactus and succulent mixes -- soil and rocks. The proportions of both will depend because cacti and succulents have different growing requirements. Almost all of my experience is with growing desert cacti, so we'll start with that.

Pumice is the perfect mineral gravel because it has the unique combination of open porosity and good moisture retention. (By the way, there's no such thing as "pumice soil".) Unless you live in a desert-type climate (which you don't -- Charleston has a humid subtropical climate), you should do well growing desert cacti with straight pumice or a pumice-granite gravel mix. If your chicken grit is crushed granite, you can use that. I grow the vast majority of my cacti in a 60/40 pumice-to-granite gravel mix, but the granite is there primarily to make my pots heavier so they don't tip over in the wind. If you don't have problems with windy conditions, you may not need the chicken grit at all. Some species of desert cactus (Tephrocactus, for example) have very fine root systems that won't be supported well in a soil-less mix, so a 50/50 pumice-to-soil mix is better for them. So-called "desert tropicals" (Melocactus, Discocactus, etc. I think Echinopsis may also apply) need some soil in the mix too, but I tend to go light on the soil for Melos and Discos. Cacti grown soil-less require being fertilized pretty much every time they're watered in the growing season. My fert of choice is Dyna Gro All Pro 7-7-7, although it's expensive, so maybe not the best choice since you have such a small collection. Dyna Gro Orchid Pro 7-8-6 is the next best choice, and you can find it in small (and more cost-effective) quantities on eBay. Dilute 1/2 teaspoon of the liquid concentrate in a gallon of water.

My experience with succulents is confined to a Haworthia attenuata in the collection, and I'm doing really well with it in a 50/50 pumice-to-soil mix. Intuitively speaking, I think that should be fine for most or all succulents, but I'll defer to members who have more experience with them. Unlike soil-less mixes, soil in the mix will retain nutrients from ferts, so you won't need to fertilize succulents nearly as often.

I've been thinking about what you might want to do with regard to potting soils. Since we know that Miracle Gro is right out, the only guidance I can give you is what to look for and what to avoid with other commercial potting soils. Something you should absolutely avoid is anything containing peat -- takes too long to wet, and once it gets wet, it takes forever to dry out. Aloinopsis was spot-on about telling you to avoid sand, so that's another red flag if you see it as an ingredient listed in a commercial potting soil. If you can find something that's just dirt and tree bark, pick out the big chunks and throw them away, then you may have an acceptable soil you can go with for your mix(es).

One last thing I'll mention. I'm a firm believer in gravel top dressings for 2 reasons -- first, they add a decorative touch. And second, they'll keep all the floaty stuff in the mix from getting all over your plants whenever you water. I can get all kinds of attractive top dressings at local cactus nurseries, although that may not be an option for you. If it isn't, a good layer of granite gravel on top will do the job. Oh yeah, almost forgot -- rinse your mineral gravels thoroughly before you put them into your mixes. Too much mineral dust is no bueno (as I found out from hard experience), so take the time to do this.
Thank you so much for the advice! It does help clear things up!!!

I'm going to do the 50/50 pumice and potting soil mix. I'm also ordering a sifter to get the larger chunks out. So I'm going to repot everything probably next weekend (that'll be two weeks after I originally repotted them) with that mix. I'll also do that top layer. Can that be done in any type of stone? My succulent buddy said I can do any stone like crush amethyst or something?

I truly appreciate your help with this!! 🙂🙂🙂
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Steve Johnson
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Re: Custom Cactus Soil Mix

Post by Steve Johnson »

victoryboxer wrote: Mon Jul 15, 2019 1:03 amI'll also do that top layer. Can that be done in any type of stone? My succulent buddy said I can do any stone like crush amethyst or something?

I truly appreciate your help with this!! 🙂🙂🙂
Glad to be of service! The only type of stone you should avoid is one containing Calcium such as limestone or gypsum.
If you just want photos without all the blather, please visit my Flickr gallery.
My location: Los Angeles, CA (Zone 10b)
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