Meet the Homalocephalas

[iann]

The original Homoalocephala texensis, frequently lumped into Echinocactus, but a recent study says it should be split. It isn't actually the size of my lawn, but it is about 12cm wide.

Also recommended is that E. polycephalus joins Homalocephala.

And ssp xeranthemoides, obviously.

Also E. parryi, similar but with shorter tidier spines (and not clumping).

An interesting bunch, especially if you like spines.

[ralphrmartin]

Wow, Ian, those are some superb examples of these very tricky to grow plants; the middle two are especially difficult.

Any tips?

[ChrisR]

I suspect Ian can grow anything......

[Herts Mike]

They are lovely plants.

[Tina]

Gorgeous, any cultivation tips.
All so lovely and green even at the base.

[KarlR]

Great plants! I'll join the others in asking for tips

[iann]

I do like to grow unusual plants and things that have a reputation for being difficult. Sometimes it works out, sometimes not. I kill plenty of plants, some deliberately testing limits and trying odd things, some accidentally when I know better, some for no apparent reason.

Coincidentally, I noticed this Glandulicactus uncinatus yesterday, looking a colour that indicating imminent death. No reason that I could think of, it isn't a particularly touchy species.

Today, with a friend, and I think it is time to start writing an epitaph.

[iann]

H. texensis isn't hard to grow with fairly standard methods. This particular plant always seems like it is a bit stressed in the sun, but it keeps on getting bigger.

E. polycephalus is the one people have trouble with. You need to remember that it only grows for about two months of the year, say March and April. Be satisfied with a couple of new areoles, which is actually a fair chunk of plant, and don't try to persuade it to make more later into summer. So I start watering in February, give or take a few weeks, whenever there is a bit of early sun to warm up the greenhouse. Cold nights, freezing or even below, are not a problem and may be helpful. Then fairly dry until late summer. It isn't as strict as something like a Sclerocactus about being dry right through summer, and leaving it too long might even cause the roots to be lost. Full sun helps the spines, any scorching is more a sign that the plant might have problems than the greenhouse being too hot. If they lose their roots, it takes a very long time to regrow them so a plant might sulk for two or three years. Probably the most difficult thing is germinating the seed.

E. parryi is a bit more normal, but still tends to push some new areoles in spring and then spend summer just maturing them.

[ralphrmartin]

Thanks Ian. I'll just pop and unwater my H. polycephala!

I once wrote an article on Glandulicactus uncinatus, and got asked to change the title to Sclerocactus uncinatus. I pointed out that it couldn't possibly be a Sclerocactus, as I can grow it! (I clinched the case by citing DNA evidence too).

[KarlR]

Thanks for the tips, Iann! I also have watered my xeranthemoides and parryi recently. They're quite young so I thought they'd appreciate some water - how old are yours when you start holding off water during summer?