Richard 2012-04-16 02:56:07
My biggest columnar cactus is rotting from the top due I think to bringing
it indoors last winter to the wrong conditions. It was about 18 inches
tall. I’ve cut of the top, applied white spirit to clean and rooting
hormone for the anti-fungicide it contains but to my dismay it has continued
to rot. Till now it has been a very fast grower. Any lifesaving suggestions
Inge jones 2012-04-16 02:56:09
White spirit? Is that what you’re meant to put on plants? I live and
Richard 2012-04-16 02:56:16
Well, it was suggested on a web page that I came across that one use alcohol
and white spirit I think does contain alcohol.
Cereus-validus 2012-04-16 02:56:31
Too late. Once rot takes a foothold, its a goner.
Ned 2012-04-16 08:26:57
…………. Till now it has been a very fast grower.
And therein could lie the reason.
Fast growing would seem to imply that the sap is/was flowing freely,
i.e. the plant is/was lush.
Cacti are not meant to be lush fast growers.
As soon as a bit of disease or rot occurs the lush plant will implode.
A hard grown plant will suffer a blemish and recover.
I’ve heard of applying the rooting powder to help seal a cut, but
never heard of applying white spirit.
The usual procedure for dealing with cut cactus sections (grafts) is
to place them in a dry area and let them self heal – and certainly
with-hold watering as that just encourages more sap to flow – and an
easy route for rot to spread.
Kay easton 2012-04-16 14:41:58
Make sure the soil it is in is dry or only very lightly wet, slice off
the top again, and carry on slicing till you get a cut surface which is
healthy green all through. Don’t apply white spirit or rooting hormone,
just leave the plant in a dry atmosphere and it should dry off quite
happily all by itself.
You might just have to accept that you’ve lost that one. Rotting at the
top isn’t very usual – usually they rot from the bottom (in which case
you slice off the bottom and allow them to re-root) or you get a sudden
collapse and find that the plant has rotted from the centre outwards.
Edward’s earthworm page:
Kay easton 2012-04-16 14:42:00
I don’t think it does! Isn’t it what is also known as ‘turps
substitute’. Nasty greasy stuff – good for cleaning wood prior to
varnishing, but I used to get it on my contact lenses, and then have to
clean it off with alcohol.
So I certainly wouldn’t use it as a substitute for alcohol.
Edward’s earthworm page:
Chris hogg 2012-04-16 14:42:45
Once rot sets into a cactus it spreads rapidly through the soft
tissue. It usually takes drastic surgery to save it, if you can save
it at all. IME you have to cut it back to a point where absolutely no
brown discolouration of the flesh is visible, and then a bit. That
probably means cutting it back severely, like in half. Use a clean,
sharp knife sterilised in meths after each cut until you get well
below the rot. And I mean meths, not white spirit, petrol, creosote or
anything else :-). Cheap and easily come by in any hardware shop.
Allow the cut surface to dry unaided in the air.
If you’re lucky, and you do save it, it will send up two or three
shoots from around the edge of the cut surface. Thin then out as
required, or even pot up the unwanted ones to grow on as new plants.
Cereus-validus 2012-04-16 14:43:10
By the time you see actual symptoms of rot, the fungal hyphae have already
thoroughly inundated the cortex and there is nothing you can do to save the
plant. Applying anything to the surface of the plant is a waste of time
because the problem is deep within the fleshy tissue of the plant that you
Throw the plant out before it infects any others. Thoroughly sterilize any
tools you have used on the plant for the same reason.
What is an anti-fungicide? Something that encourages fungal growth?