"Jeff Layman" wrote in message
...
"Craven" wrote in message
o.uk...
Hi, I have a very old cactus that I don't water often.

I noticed this week the new growth at the top is going brown (an
unhealthy brown) on one side. The cactus is about 3.5 foot tall - the
last 5" are affected.

I suspect it's overwatering as it turns out someone has been watering it
for me (a kind gesture but...).

Obviously I'll stop watering it for a while... a long while!

Does anyone know if they generally recover? I've never been in this
situation before.

Thanks a lot,

Craven.

I have (very nearly "had"...) a Cleistocactus straussii which I'd had for
20 years, and was always treated the same way. It had 3 stems - each 4 -
5 cm in diameter and about 120, 90, and 30 cm high, and flowered every
year. Last year the tallest stem started to go soft at the top, and
gradually died back. Despite cutting it back well below the damaged area,
it still kept going soft (even though it was kept completely dry, and it
was by now summer) and continued to die back. The next tallest also now
started to go soft, and eventually the shortest stem did too. I cut them
all back to about 10 cm. I couldn't tell if they had stopped dying back,
but as I hate to chuck anything away, I stuck it under the bench. A
couple of months ago I looked at it. There was no further change to the 3
stems as far as I could see, but a new stem had appeared from below soil
level! That is now about 3 cm high, and looks healthy.

I have no idea what happened to my cactus, but it may be worth you doing
the same thing to yours if you think it will save it. What species is it?

By the way, is the brown area hard or soft? If it's soft, it may well be
rot or another fungal disease. If it's hard, and a bit scabby, I have
heard it said that it can be due to a trace element deficiency. In the
latter case, the cactus should grow through the problem and start turning
green again. Whatever, if you don't water it again until next March or
April it can't do any harm.

--

Jeff
As Jeff says, they often come back to life when least expected. You could
try ripping a live bit off the side, if you have a spare bit, let it dry out
for a while, and then stick it in vermiculite to see if it takes root. So
then you'll have two!

I have a lot of epiphyllums and they go scabby from time to time, I didn't
know that it was a trace element deficiency, thank you for that, I shall
have to feed them more.

someone