Geohintonia! Etc.!

[LophoFan]

I'm growing aztekium from seed as well. So I know how it is with these slow growing plants. I plant to start a bunch of these slow growers all at once. I'm also going to give ortegocactus a go. Those ones look so cool. Pretty stoked. I don't know what i'm going to do in 5 years though when all these seeds i started grow up!

[DaveW]

Geohintonia's are faster from seed than Aztekium ritteri LophoFan and Aztekium hintonii grows about the same rate as Geohintonia. Here is my A. hintonii I grew from seed, it produces the spiny bristles and wool at the top when it starts flowering. It does not seem to present any difficulties in cultivation. It also seems to produce those stripy flock bands on the body like Astrophytum ornatum when young. As you can see it does not really produce the pseudoribs between the normal ribs as A. ritteri does.

hintonii.jpg (97.49 KiB) Viewed 1728 times

[Steve Johnson]

Geohintonia's are faster from seed than Aztekium ritteri...

Okay, since my Geohintonia was grown from seed by Tee Dee, I'll need to look at before-and-after photos going from March to the end of summer. Then I'll see if there's enough noticeable growth progress to have it show up on the forum. Perhaps I am overestimating how slow they are. Such being the case, here's a pertinent tie-in question, although it may be rhetorical...

I really need to get the Geohintonia out of the perlite-compost mix Tee Dee has been growing it in. Of course that entail a transplant into my trademark pumice-DG mix and a pot size I believe should be more suitable. Then the roots will have to re-establish -- is that time period commensurate with normal growth rate for the plant itself? If so, my feeling is that the root system won't be fully re-established until next year, and I can't expect to see anything beyond just a touch of new growth this summer. However, if I'm wrong and the Geohintonia's roots beat my expectation as they get going more quickly, then I'll be very pleasantly surprised about what happens! I'll need to observe the results for myself over the growing season, but all I can say for now is that it'll certainly add to my ongoing cactus experience.

[DaveW]

I don't think Geohintonia's are any trickier than Aztekium hintonii. Although some cacti can be difficult to re-root like Melocacti, many will root reasonably easy in the normal growing season. However de-grafted plants or collected plants that have lost their roots may be trickier to root. However yours is a cultivated seedling already rooted so should give no more problems re-establishing it than most cacti.

I have to ask why the hurry to get it out of the potting mix it has happily been growing in from a seedling and why you think it will automatically grow better in yours? Most nurserymen have perfected their potting mix over the years to grow the plants they deal in. Far better to wait until the growing season when you see new signs of growth and re-pot then. Why should your compost mix be any better for it than the one it was successfully raised in? You simply need a similar watering and fertilising regime to that Tee Dee used. From what I have seen of UK cactus nurserymen they all have very different potting soils, but their plants seem to grow well in them all.

As I said elsewhere, a friend of mine in Malta grows all such plants very well in just peat and sand, as do many Continental cactus nurseries, so there is no such thing as an obligatory correct potting mix for any cactus, they just require it to be well drained and provide all the required nutrients and trace elements and be the right PH. My hintonii in the picture above has been in several different potting mixes since it was raised from seed as I often keep changing them, but it seems to have grown OK in all of them, from mainly mineral to soil and peat based.

[Steve Johnson]

I have to ask why the hurry to get it out of the potting mix it has happily been growing in from a seedling and why you think it will automatically grow better in yours? Most nurserymen have perfected their potting mix over the years to grow the plants they deal in. Far better to wait until the growing season when you see new signs of growth and re-pot then. Why should your compost mix be any better for it than the one it was successfully raised in?

Fair questions, although apparently you don't know my climate. First, I'm not in a hurry to repot the Geohintonia just yet. I'll wait until the weather is warm enough so I can catch the start of the growing season and give it as much time as possible to let the roots settle in and re-establish. In my area that's usually early to mid-March, although I go purely by suitability of the weather -- not what the dates on the calendar say. If March ends up being cooler than I'd like, I'll wait until the nice, warm days kick in whenever it happens. Second, Tee Dee's climate is hotter and much drier than mine in summer. The high humidity in my coastal microclimate has worked out pretty much perfectly for the pumice-DG mix I've been using over the last 2 years. If I stayed with Tee Dee's mix, the high amount of organic material would cause it to stay wet too long before it dries out properly after deep watering. Knowing one's local conditions should trump what growers elsewhere are doing, so following someone else's practice isn't helpful without a close "apples-to-apples" similarity in growing conditions. By the way -- no disrespect to Tee Dee's growing approach, but I'll take pumice over perlite every day of the week. Those who've tried both generally agree.

[C And D]

Aztekium hintonii
YES, Yes and yes
they grow at about the same rate,
somehow related
and are more beautiful than Geohintionia

My 2 large ones are about 15-18 years old, the same as my large Geohintonias

IMG_3864.jpg (56.25 KiB) Viewed 1691 times

my oldest one has an ancient look to it
Mike W. may remember this plant, I grabbed it seconds before he was going to nab it, at a OCCSS show about 11-13 years ago.
I will repot it next Spring.

IMG_3892.jpg (60.69 KiB) Viewed 1691 times

This one may be a year or 2 younger.
I repotted it last summer, so it hasn't fattened up yet.

IMG_3899.jpg (56.65 KiB) Viewed 1691 times

Here is a ~10 year old seedling that I was able to buy 2 years ago
normally they are very slow growers
They are hard to find these days.

IMG_3874.jpg (53.82 KiB) Viewed 1691 times

I did get a couple seeds this year, they're in there somewhere, I have to bank the pollen since the only 2 flowering ones usually don't flower at the same time.
I hope to get a lot more seeds in the future.

[C And D]

I just did some googling on the subject of Geohintonia as a hybrid with Aztekium huntonii.
I heard about this long ago, and knew that they were going to do some DNA studies, what was the outcome??

I couldn't find much, except this

It is suggested that Geohintonia may represent an intergeneric hybrid involving Aztekium (probably A. hintonii which is sympatric with Geohintonia ) and possibly Echinocactus horizonthalonius.

http://www.floralibrary.com/flora/cactu ... ter=1&lang" onclick="window.open(this.href);return false;


So this site says it's "possibly" Echinocactus horizonthalonius
I would think DNA studies could do better than that.
Anyone else have some more info on this?

[DaveW]

I have heard the intergeneric hybrid thing too, as well as the other way around in that A. hintonii could be a hybrid between Geohintonia and A. ritterii, but I don't think any DNA studies have yet been done, so at the moment it's just speculation. That then raises the question where does A. valdezii fit in?

http://www.hscactus.org/mar10pom.html" onclick="window.open(this.href);return false;

David Quail in the UK raises A. hintonii (and Geohintonia's) in quite significant numbers from seeds off his own plants now:-

http://www.aristocacti.co.uk/index.htm" onclick="window.open(this.href);return false;

Pictures at the end of this link give some idea of the growth rates:-

http://www.living-rocks.com/quail2.htm" onclick="window.open(this.href);return false;

I suppose if one speculates about intergeneric hybrids, what could Digitostigma be a hybrid with, obviously one parent would be an Astrophytum?

[phil_SK]

It strikes me as significant that it's always the newly discovered plants about which the 'is it a hybrid?' question arises, never something we've known about for a century.

[DaveW]

What about Echinocactus grusonii Phil which may possibly be an antique cross between an Echinocactus and a Ferocactus, also Astrophytum ornatum may again be a past cross of an Astrophytum with an Echinocactus.

Backeberg back in the 1960's I think it was suggested some of the genera of cerei we now recognise could have started as intergeneric crosses in the dim distant past.

[CactusFanDan]

Since we're talking Geohintonia growth rate, here's a little something I just threw together. Hopefully this will give you some idea of how fast these plants grow. From 1-2mm to over 1cm in less than a year. Could be worse.

Geohintonia growth.jpg (41.61 KiB) Viewed 1649 times

[BRC]

Well that doesn't seem that slow, thanks for the pics Dan!!

[Thord Hakansson]

About Geohintonia-as a seed grown plant it will eventually develop a very big root,so will need a deep pot. Winter is a good time to repot, since the plant isn´t going to be disturbed during its growing period and the roots will have time to heal before watering starts. Ortegocactus is as fast growing as any other cactus, so after three/four years you will have a flowering plant.
Thord

[LophoFan]

That's good to know. I was told ortegocactus was slow growing (I guess you can call any cactus slow growing from seed though)

[sabotenmen]

About Geohintonia-as a seed grown plant it will eventually develop a very big root,so will need a deep pot. Winter is a good time to repot, since the plant isn´t going to be disturbed during its growing period and the roots will have time to heal before watering starts. Thord

I've heard this a couple times before and it sounds tempting. Many experienced growers ,however, never repot in winter. Why not? My question is, does a dormant plant's roots heal at all? Won't the plant just wait until spring and then start growing activity (which includes regenerating any damage to its roots) ? When you repot the plant in its active (!) growing season, aren't the roots more likely to quickly heal? I mean, we want them to heal quickly, right! We wouldn't want the roots to stay damaged through the whole winter or even a part of winter!