Are you growing your cacti in a soilless mix?

[Steve Johnson]

Again, I'm just here experimenting and stuff, nothing too crazy.

I'm at kind of a disadvantage because I live in a 2nd-floor apartment. and the growing space I have is limited to 12 square feet on the balcony. If I had a lot more growing space, here's what I would do:

• Select cactus species that are easily available and get 3 or 4 individuals of the same species. Pot them up with 3 or 4 different mixes, then see which test individual does best over time. The idea here is that you can get an apples-to-apples comparison.

If you have enough growing space to test a few different species (and I would recommend relatively fast growers over slow-growing cacti), I think a year or two would be enough to get valid results. The only thing you won't want to experiment with is fertilizer -- settle on a fert regimen you're satisfied with and apply it equally to all of your test cacti. Using different ferts on plants in the test group may (and probably will) skew the results.

This is the blending of art and science -- the science is experimentation, and the art is enjoying well-grown cacti resulting from your experimental successes.

[Mrs.Green]

• Select cactus species that are easily available and get 3 or 4 individuals of the same species. Pot them up with 3 or 4 different mixes, then see which test individual does best over time. The idea here is that you can get an apples-to-apples comparison.

If you have enough growing space to test a few different species (and I would recommend relatively fast growers over slow-growing cacti), I think a year or two would be enough to get valid results. The only thing you won't want to experiment with is fertilizer -- settle on a fert regimen you're satisfied with and apply it equally to all of your test cacti. Using different ferts on plants in the test group may (and probably will) skew the results.

This is the blending of art and science -- the science is experimentation, and the art is enjoying well-grown cacti resulting from your experimental successes.

Such an experiment would certainly be interesting but I think you would need way more than 3-4 specimens of each species to give a trustworthy result. I would think more like at least 30 plants from each species and from different sources. As every grower knows, there ban be huge differences in ‘vitality’ if you sow or plant cutting/offsets. Even when the plants are grown under the same conditions( placement, soil, temperature and so fort)
Using only 3 or 4 specimens, you could risk testing on two ‘runts in the litter’ and two ‘healthier’ specimens and that would certainly skew the results.
Another thing to considerate, should the test be done only at your place or should the same test be done by growers with fairly different conditions? If one only want to know whats working for oneself ( and that may be the main interest for most growers?) testing different growing conditions as climate zones may not be necassary.

[Mrs.Green]

• Select cactus species that are easily available and get 3 or 4 individuals of the same species. Pot them up with 3 or 4 different mixes, then see which test individual does best over time. The idea here is that you can get an apples-to-apples comparison.

If you have enough growing space to test a few different species (and I would recommend relatively fast growers over slow-growing cacti), I think a year or two would be enough to get valid results. The only thing you won't want to experiment with is fertilizer -- settle on a fert regimen you're satisfied with and apply it equally to all of your test cacti. Using different ferts on plants in the test group may (and probably will) skew the results.

This is the blending of art and science -- the science is experimentation, and the art is enjoying well-grown cacti resulting from your experimental successes.

Such an experiment would certainly be interesting but I think you would need way more than 3-4 specimens of each species to give a trustworthy result. I would think more like at least 30 plants from each species and from different sources. As every grower knows, there ban be huge differences in ‘vitality’ if you sow or plant cutting/offsets. Even when the plants are grown under the same conditions( placement, soil, temperature and so fort)
Using only 3 or 4 specimens, you could risk testing on two ‘runts in the litter’ and two ‘healthier’ specimens and that would certainly skew the results.
Another thing to considerate, should the test be done only at your place or should the same test be done by growers with fairly different conditions? If one only want to know whats working for oneself ( and that may be the main interest for most growers?) testing different growing conditions as climate zones may not be necassary.

Another factor; as far as we know, every species goal is to survive . As we all know, living conditions can change and if your requirements is very rigid ( on species level) you may risk going extinct. So it’s smart to ‘try out’ different variations in case of change of conditions or improvement. I think this may be part of the answer why some plants ( as in individuals) seemingly can thrive and flourish under the ‘wrong conditions’ when another plant (same species) may perish.

I do think we are only just scraping the surface when it comes to knowledge on life, unfortunately a lot of knowledge will probably never be revealed as we as species ( Homo sapiens) do everything we can to destroy the planet as fast as we can.

[Mrs.Green]

Uhm..don’t know why my post appears twice and as a quote when adding something?

[Steve Johnson]

Such an experiment would certainly be interesting but I think you would need way more than 3-4 specimens of each species to give a trustworthy result. I would think more like at least 30 plants from each species and from different sources. As every grower knows, there ban be huge differences in ‘vitality’ if you sow or plant cutting/offsets. Even when the plants are grown under the same conditions( placement, soil, temperature and so fort)
Using only 3 or 4 specimens, you could risk testing on two ‘runts in the litter’ and two ‘healthier’ specimens and that would certainly skew the results.
Another thing to considerate, should the test be done only at your place or should the same test be done by growers with fairly different conditions? If one only want to know whats working for oneself ( and that may be the main interest for most growers?) testing different growing conditions as climate zones may not be necassary.

That's the whole point of the experiment I suggested for Jimmy -- it's designed to help different growers determine what works best under their local conditions, not what's supposed to work best for all growers under all conditions. I'll refine it a bit further by stating that 3 or 4 specimens of the test species should A. be grown plants well beyond the "tender" seedling stage, and B. come from the same source. As in the same nursery where we buy the test cacti. Can't speak of your situation in Norway, but here in the US reputable cactus nurseries are easy to find (both brick-and-mortar and online), so they're great sources for buying multiple specimens of the same species. For our US members who are so inclined, I'll highly recommend Miles Anderson of Miles' To Go:

http://www.miles2go.com/

Miles is an excellent grower, and if US members get the test cacti from him, the number of same-species individuals they need will depend on how many different mixes they're testing. And because they'll be starting their experiments with well-grown plants, the test results with different mixes should be valid. If growers want a bigger test sample, make it 2 or 3 specimens of the species times the number of different mixes to give you the total number of same-species plants you'll need for the test. Mrs. Green, I do understand what you were trying to say, but I think that at least 30 plants from each species is overdoing it.

[Mrs.Green]

I will give you an example why I think only 3-4 specimens is inadequate About a year ago I stripped an Echinopsis sp ( probably oxygona) for all its pups. I kept seven of these and potted them in same size pots and in the same mix. I will only include six of these in this ‘test’ as one of the pups is placed in a different window. The remaining six were potted up as single plants apart from three of them, since I was out of suitable sized pots at the moment. So in total four pots. This four pots had the same mix in them and all placed close together on the same windowsill. They were given the same amount of water and fert, at the same time.

So these pups came from the same source and lived under the same conditions and microclimate.initially the three cramped together in the same pot grew fastest without doubt. About a year later all have grown quite a bit exept for one pup( alone in a pot). Its alive and plump but havent doubled it’s size like the others. If I had used these plants as a test on lets ay 4 different soilmixes, it would be easy to conclude that mix nr.4 ( the plant with little growth) wasn’t a good mix.

[zpeckler]

I only have a few cacti in soilless mixes: two Mammillaria grahamii and two Mammilloydia candida. They're planted in 100% Turface MVP, mainly because that's what "The Beginner's Guide to Cactus" by Scott Calhoun--one of the first serious books on cacti I got--specifically recommended for those two species. All four plants are doing well so far. The rest of my collection has a little bit of soil in the mix, just 25-33% depending on my experience with the plant. Summer temps here in the Sac Valley CA routinely are over 100F, and I find that a little soil does improve water retention which a lot of my plants seem to like. My collection is mostly desert plants, with the few exceptions being a single Rebutia, a few Cleuseocactus, a few Trichocereus, and an Espostoa. For the last few years I have been strongly tempted to try a soilless mix for a lot of the Sonoran and Mojave species I have, but haven't had the guts to change up a regimen that's worked pretty well so far.

Do you guys have thoughts on a soilless mix in the kinds of summer temps I see?

[Tom in Tucson]

I only have a few cacti in soilless mixes: two Mammillaria grahamii and two Mammilloydia candida. They're planted in 100% Turface MVP, mainly because that's what "The Beginner's Guide to Cactus" by Scott Calhoun--one of the first serious books on cacti I got--specifically recommended for those two species. All four plants are doing well so far. The rest of my collection has a little bit of soil in the mix, just 25-33% depending on my experience with the plant. Summer temps here in the Sac Valley CA routinely are over 100F, and I find that a little soil does improve water retention which a lot of my plants seem to like. My collection is mostly desert plants, with the few exceptions being a single Rebutia, a few Cleuseocactus, a few Trichocereus, and an Espostoa. For the last few years I have been strongly tempted to try a soilless mix for a lot of the Sonoran and Mojave species I have, but haven't had the guts to change up a regimen that's worked pretty well so far.

Do you guys have thoughts on a soilless mix in the kinds of summer temps I see?

I know how hot the inland valleys of California can get (having lived there for over 30 years), but the Sonoran and Mojave deserts are far hotter. The CA coast and valleys cool off far more at night in the summer. and that makes a huge difference to growing succulents from the American deserts. Even with my advantage of growing these difficult species in a more suitable climate, I've found that too much organic matter in the soil will lead to their early demise. Remember: "Your mileage may vary".

[zpeckler]

I know how hot the inland valleys of California can get (having lived there for over 30 years), but the Sonoran and Mojave deserts are far hotter. The CA coast and valleys cool off far more at night in the summer. and that makes a huge difference to growing succulents from the American deserts. Even with my advantage of growing these difficult species in a more suitable climate, I've found that too much organic matter in the soil will lead to their early demise. Remember: "Your mileage may vary".

Thanks for your experience, Tom. Looking at climate averages on Wikipedia, Tuscon temps look to be fairly comparable to mine, with the exception on your summer monsoons whereas--as you well know--my summers are bone dry for months. I'm these conditions, are there any particular genuses or species you find do particularly well in these conditions?

[Tom in Tucson]

Some of the best species I've seen in the Sacramento and San Joaquin valleys are: any Cereus sp., most Ferocactus, Kroenleinia grusonii, and almost all prickly pears.

[zpeckler]

Some of the best species I've seen in the Sacramento and San Joaquin valleys are: any Cereus sp., most Ferocactus, Kroenleinia grusonii, and almost all prickly pears.

Awesome, dude. I have tons of Feros--it's probably the genus I have most of. For Echinocactus species I of course have a few grusonii, but also platyacanthus and horizonthalus. Lots of prickly pears too because people keep gifting me cuttings! A bunch of cholla that all do really well in the heat too. Basically I have a ton of heat-tolerant species I could experiment with.

Maybe this winter when I do my annual repotting I'll change some to a pure mineral mix....

[Tom in Tucson]

Some of the best species I've seen in the Sacramento and San Joaquin valleys are: any Cereus sp., most Ferocactus, Kroenleinia grusonii, and almost all prickly pears.

Awesome, dude. I have tons of Feros--it's probably the genus I have most of. For Echinocactus species I of course have a few grusonii, but also platyacanthus and horizonthalus. Lots of prickly pears too because people keep gifting me cuttings! A bunch of cholla that all do really well in the heat too. Basically I have a ton of heat-tolerant species I could experiment with.

Maybe this winter when I do my annual repotting I'll change some to a pure mineral mix....

If you get a chance I'd enjoy seeing a few pics of your Feros.
Sorry to post the last few OT replies.

[zpeckler]

If you get a chance I'd enjoy seeing a few pics of your Feros.
Sorry to post the last few OT replies.

Ah yes, we are wandering a bit from the original topic. I'm on vacation at the moment, but I'll start a new thread and post some pics when I get back. I've been meaning to start a running blog but just didn't get around to it this season. My collection is small compared to some here on the forums, but out of about 60 plants about a third if them are Feros. I've only been seriously growing cacti since 2026, so most of them are still pretty small.

Edit: Since 2016, not 2026 obviously!

[Tom in Tucson]

If you get a chance I'd enjoy seeing a few pics of your Feros.
Sorry to post the last few OT replies.

Ah yes, we are wandering a bit from the original topic. I'm on vacation at the moment, but I'll start a new thread and post some pics when I get back. I've been meaning to start a running blog but just didn't get around to it this season. My collection is small compared to some here on the forums, but out of about 60 plants about a third if them are Feros. I've only been seriously growing cacti since 2026, so most of them are still pretty small.

I assume you mean '16. I look forward to seeing them. Enjoy your vacation!

[Mrs.Green]

I've only been seriously growing cacti since 2026, so most of them are still pretty small.

If you started growing in 2026, no wonder your cacti are still pretty small.. Sorry, I couldn’t help myself, I just had to..