"Cereus-longispinus" wrote in message . com...
From what you say, you have many more problems than needing to cut back your
plants.

The plants are most definitely in pots that are too large and are suffering
because of it. The soil may be stagnant, septic and killing the roots of the
plants.

or they have been too long in one pott and exhausted one particular
nutrient.
But collapsed soil ( what stan sez) is quite possible. I avoid both
these problems by replacing some of the soil and add in a few
earthworms and some manure every year.


Does the soil have a foul odor?

Do your pots have drainage holes in the bottom?

if not, that would explain the bad soil. It should not be too much
work to pull out one plant, check that it is not rootbound, check the
soil quality, and replace some of it.