There are several things that might be wrong with your cacti.
First of all, since no fertilizer had ever been added, the plant might be
suffering from a lack of nutrients. I suggest you try a slow release
fertilizer which allows for nutrients to be released over a six to eight
month period. You should check your local nursery or garden store to see
what fertilizers are available.
Also, the idea of an 11 ft. plant in a 1 ft. pot seems awkward.
You might want to transplant the cacti to a larger pot. Your plant might
be root bound, which means the roots have out grown the pot.
Finally, you might want to rethink your water schedule. Cacti
need to be watered frequently in the summer, and need to be kept cool and
dry in the winter. Think about the plant's natural environment.
I hope some of this is useful.
On 20 Feb 1995, Naera Kim wrote:
> We have a Cereus(Peruvian) cactus that is about 11 ft. high. The former
> owner of our loft left two of the cactuses because of the size. The first
> cactus died a year after we moved in and now two years later the second
> one is turning yellow and dying as well. Pretty scary.
>> Our cactus gets plenty of sunlight from the east view ( not to mention it
> stands right in front of the window that is 15 feet high.) We normally
> water them every two months but it has never been fertilized or repotted.
> The pot is about 1 ft. in diameter and 1 ft. deep.
>> We don't know much about how to take care of this dying cactus and we're
> planning to call a garden store near by.
>> I would appreciate any information concerning this cactus. please send
> E-mail to naera at lightbulb.com>> thanks,