Squishy part on Astrophytum asterias nudum

[wetpossum]

I have had an A. asteraus nudum for about a year, been mostly in my greenhouse under ~30% shade cloth. I've been keeping a close eye on it given my poor track record with the species, and about 2 or 3 days ago I noticed a squishy spot on the north side of the plant. I bare-rooted it, put it in a pot with super chunky pumice, and put it on a shady lower shelf.

Watering has been infrequent, but it's been getting a splash of water maybe once a month since it's warmed up.

Is it doomed? is there anything I should try to do to save it?

IMG_20150410_191702000.jpg (43.41 KiB) Viewed 2881 times

[wetpossum]

Good Side:

IMG_20150410_191644119.jpg (57.75 KiB) Viewed 2879 times

Bad Side:

IMG_20150410_191630673.jpg (41.34 KiB) Viewed 2879 times

[Steve Johnson]

Squishy isn't good, and I'm about 99% sure that your plant has rot. If so, then unfortunately the rot has progressed to the point where the situation may not be salvageable. Although Astrophytums in general are rather easy, asterias tends to be quite particular about how it wants to be grown. Assuming the worst about your asterias nudum, here are a few tips that should help if/when you get a new one:

1. Persistent moisture in the roots is what gets people in trouble, so you should let the mix go completely dry top-to-bottom between waterings during the growing season. In summertime, overnight lows above above 68-70 can put many desert cacti to sleep. Not sure if you see this with your other cacti, but if you do, periods of summer dormancy may not be the best time for watering your asterias. Although I'm able to give mine very occasional light watering in winter, the overnight lows in your winters may be too cold for it.

2. The mix should be very lean. If your climate wasn't so dry, I might even go so far as to recommend straight pumice. However, it may dry out too fast for you, so you'll probably want to add some soil -- just off the top of my head I'm thinking a 70/30 pumice/soil mix. Avoid anything containing a lot of organic materials. Following on point #1, my guess is that you should be watering asterias every 2 weeks in spring, then once a week when things start heating up in summer.

3. I'm a big advocate for getting cacti bare-root whenever possible. While I wouldn't necessarily turn down a plant just because it's potted, the first thing I'll do is unpot it, clean the existing mix out of the roots as thoroughly as possible, then repot in the mix I use. This procedure is a royal pain in the backside, and the situation is easier when cacti have been thoroughly prepped by reputable sellers shipping bare-root cacti. Miles' To Go stocks asterias nudum, so that would be a great source for you.

4. A. asterias is remarkably intolerant of being over-potted. Size the pot so there's a margin of no more than 1/2"-3/4" around the roots.

Hope this helps!

[greenknight]

Odd that it's not discolored, though, if it's rot.

[Steve Johnson]

Odd that it's not discolored, though, if it's rot.

That's what I would've thought until I saw a Copiapoa hypogaea rot on me almost 2 years ago. A cautionary tale here:

http://www.cactiguide.com/forum/viewtop ... 6&p=275275" onclick="window.open(this.href);return false;

[greenknight]

In this case, though, the roots appear to be healthy. If it had root rot, I'd understand what's going on.

[hegar]

A rot does not necessarily have to enter through the roots. A wound will be an "open door" for any kind of organism, including bacteria and fungi that may cause a rot. On the close-up image of the cactus, showing the "bad side" on the lower left bottom of the right affected segment there seem to be two holes. If that is the case, this would be a portal of entry for a rot organism.
I do not know, if excising these two segments - if there is indeed a rot present - and then treating the cut surface with an antibiotic would be something that could be done to save the plant.
Was that cactus subjected to perhaps a "crushing type injury"? If it was dropped or crushed, that may also cause a softening of the tissue in the affected region. I am not sure though, if the plant would just heal itself or if it actually could cause its demise.
By now, you have most likely seen a change in the condition of your plant. Has the softness area increased or has it hardened somewhat?

Harald

[Cactus Charlie]

I had a similar problem with an Asterias nudum, which had been attacked by mealies and not watered enough. It looked like yours and was hard to touch all over including the 'dented' parts. It has (nearly) returned to normal now after being watered more often and generally being looked after a bit better! If it is actually squishy and soft rather than dented and hard though it must be something else...

[greenknight]

Might borers attack an Astrophytum? I know they usually hit Opuntias, but...