Austrocacti

[ralphrmartin]

A couple of my Austrocacti were in flower today:


Austrocactus sp. HS52

Austrocactus bertinii SAR4122-5

[sechjoh]

So beautiful flowers!

[juster]

Agreed, really lovely blooms

[esp]

Lovely plants, Ralph.
How big / old are these? I’m trying to gauge how close some of my seedlings may be to flowering.

[ralphrmartin]

Probably not very old, only say 6 or 7 cm high. These were bought plants. I have grown some from seed, and they are almost as big after a couple of years, although have not flowered yet.

Here's another one: Austrocactus gracilis PHA2138

[Tony R]

Lovely plants and flowers, Ralph.
I gave up growing this genus in my younger years after several failures.
Perhaps I should have another go in my dotage!
Best,

[KarlR]

Great plants Ralph!

I haven't really grown this genus before, but decided to have a go this year. So I sowed 13 pots worth of Austrocactus. Most, if not all, the species. Seeds were from Jan Novak and Pavel Pavlicek in Czechia.

I sowed them like I do most of my cactus seeds. No sterilisation of the seeds, no fungicide, soil treated with boiling water before sowing. Pots placed in bags. I sowed about 60 pots over a couple of days - various genera from N & S America and all placed in bags of two pots per bag. This treatment is usually enough to keep everything nice and algea/fungus free for at least four weeks in a bag.

So, to come to the point, every single pot with Austrocactus seeds (in 6 separate bags) were attacked by fungi - a kind with long hair-like whitish threads, while every other pot was (and still is) untouched by fungi (and algea). It's been three weeks since I sowed this batch and there is still no sign of fungi in any other pot.

The seeds looked perfectly clean, and with no signs of fruit residue. I get fungi from time to time, but it's not a big problem for me. Usually maybe one pot in 30 gets some fungal growth, but to get it in every pot of a single genus is strange.

It looked like the seeds were the epicenter of all the fungal growth so I can only assume that the fungi came with the seeds. Has anyone had similar experiences with Austrocactus? I will certainly sterilise the seed coats of any Austrocactus I sow from now on.

[ralphrmartin]

See another thread: the Sarnes advised using sulphuric acid to treat the seeds before sowing. It works, but you need a licence these days to obtain and use sulphuric acid.

[nobby]

Sulphuric acid helps with germination (if you don't want to try it several times - we get older and have less time). Against fungus, for example, cleaning the seeds in warm water at 52° for about 10 minutes helps. But usually fungus is no problem when sowing washed Austrocacti seeds.
Sometimes it is helpfull to use H2O2 (Hydrogenperoxide) to clean the seeds.

Nobby

[Chris L]

I got a few seeds to germinate from those I ordered from Norbert last year.