What are the smallest cacti species of all?

[keithp2012]

I want a tiny cactus that will stay small and do well in a mini terra cotta clay pot.

[greenknight]

Blossfeldia liliputana is the smallest.

[keithp2012]

Blossfeldia liliputana is the smallest.

Thank you, that is tiny!

[DaveW]

Though some Fraileas's may vie for the title.

[esp_imaging]

Aztekium ritteri will take a long time to outgrow even a tiny pot, as will lots of other choice (and relatively hard to grow) species.

Lots of cacti stay small, and will take many years to outgrow a (say) 4" pot. Check out various (by no means all) species of Mammillaria, Rebutia, Parodia, Gymnocalycium, Escobaria, Turbinicarpus and many more. These will be cheaper and easier to obtain and keep alive than Blossfeldias and Aztekium (both of these are often grafted, as they are a bit tricky grown on their own roots).

[keithp2012]

Aztekium ritteri will take a long time to outgrow even a tiny pot, as will lots of other choice (and relatively hard to grow) species.

Lots of cacti stay small, and will take many years to outgrow a (say) 4" pot. Check out various (by no means all) species of Mammillaria, Rebutia, Parodia, Gymnocalycium, Escobaria, Turbinicarpus and many more. These will be cheaper and easier to obtain and keep alive than Blossfeldias and Aztekium (both of these are often grafted, as they are a bit tricky grown on their own roots).

Why are Blossfeldia liliputana tricky to grow on their own roots? They survive dry conditions as well as wet ones, wouldn't the thrive in a small clay pot?

[C And D]

Both Aztekium and Blossfeldia are very difficult on their own roots
but the hardest part is finding them for sale

So if you can find one, please send that info to me, because I love difficult plants

You should really just get a nice Turbinicarpus like andersonii or klinkeranus
They will be happy in a small pot and you can get the whole Turbinicarpus collection in small pots while your at it.

[keithp2012]

Both Aztekium and Blossfeldia are very difficult on their own roots
but the hardest part is finding them for sale

So if you can find one, please send that info to me, because I love difficult plants

You should really just get a nice Turbinicarpus like andersonii or klinkeranus
They will be happy in a small pot and you can get the whole Turbinicarpus collection in small pots while your at it.

But you still didn't answer why they are so difficult on their own roots?

[Aiko]

Both Aztekium and Blossfeldia are very difficult on their own roots
but the hardest part is finding them for sale

Seeds are easy to obtain, though. But growing them from seed is probably harder than keeping plants of flowering age alive.

[Robb]

But you still didn't answer why they are so difficult on their own roots?

To a certain degree, I believe this is down to the fact that they are difficult to grow from seed and stay so tiny for so long. Hence, we come to the conclusion that they are extremely difficult to grow on their own roots as adult plants. This combined with the fact that few own root plants are available for sale because getting them from seedling stage to adulthood is quite a challenge, leads them to acquire the label of extremely difficult. In my opinion, they are not extremely difficult to cultivate, however they are more difficult than say your run of the mill Mammillaria.

To more concisely answer your question, they are difficult to grow because they have a large taproot and as a result are rather rot-prone.

[greenknight]

As I understand it, the problem with Blossfeldia is mainly their extremely slow growth. They can stand a lot of drying once they're large enough, but keeping them alive long enough to reach that size is hard. Using the baggie method and keeping them bagged for a long time is the easiest way - you need to sterilize really well so you can do this.

Aztekiums are even slower growing. I think that says it all.

Fraileas are much easier, grow readily from seed if it's fresh. Need hot weather for the flowers to open, and they're not very long-lived, are their drawbacks. They set seed even if the flowers don't open (cleistogamous) and frequently reseed themselves - so you can just grow new ones when they kick off.

Robb posted the above while I was writing this, so if it's a bit repetitive...

[C And D]

Both plants are readily available as grafted plants

But if you try rooting a nice healthy cutting, you have little chance of getting it to root and live long term.
I've tried over and over.

Some of my Blossfeldia cuttings lived for several years, but I can't say they were thriving, they were in a kind of long term stasis of slowly dying.

I also once had a 1/2" Aztekium ritteri on it's own roots, I killed it by over watering.
All grafted cuttings failed to root.

Azetium hintonii isn't a problem on it's own roots, but gets pretty big, and again, hard to find.

But to further the discussion, Blossfeldia are not impossible to grow on their own roots, you just need a certain well established one that will be impossible to find, like this one, which I've had now for about 10 years:
This photo was from 2010,

IMG_4626.JPG (88.84 KiB) Viewed 4343 times

Today

IMG_9811.jpg (55.43 KiB) Viewed 4308 times

[Fatich]

I dont remember exact date but they could be around 3 months old. They are around 2-2,5mm.

Blossfeldia companiflora

[keithp2012]

Here is my blossfeldia liliputana specimen doing pretty good on its own roots.

1F279A31-5DA0-4814-AED3-1E066890535B.jpeg (223.02 KiB) Viewed 2659 times

[DaveW]

Blossfeldia's are not hard to grow on their own roots once a reasonable size. They are however tricky from seed the first few years through the seedlings being so small and slow growing, which is why like Aztekium ritteri they are usually grafted to propagate them. The problem is trying to root them down from grafts later as they then seem reluctant or impossible to root.

I had this one as a small plant on it's own roots from Tom Jenkins, a nurseryman in the UK, who grew it from seed. I grew it for many years with no problem until I lost it in a bad winter. It was about 10 years old in the picture and the coin is 1 inch = 2.5cm diameter.

Blossfeldia-lilliputana3.jpg (88.47 KiB) Viewed 2649 times

I did read once that they grow in cracks on banks or cliffs close to water, but how true that is I do not know. Here is one in habitat.

blossfeldia.jpg (103.89 KiB) Viewed 2650 times

Afraid if you want one on it's own roots you are going to have to grow it from seed yourself and patiently wait for it to gain size, since growing from seed for plants on their own roots is not a commercial proposition for nurserymen with such choice but slow growing cacti. Also these plants are small in habitat, you don't get the oversized and way out of character plants you sometimes see in shows in nature which some seem to desire.