Question
hi--Ive got a cactus that I have had for about 11 years...it is a six-sided single stalk,(not sure of the name)
...Its about 5 feet tall...the bottom 2/3rds is a greenish color,while the top is a deep blue.
---anyway,the top (approx 1 ft)has bent over in the last few days...is this normal ,or is there a problem with the plant ??
thank you
John

Answer
Dear John,

Your plant sounds like a Cereus Peruvianus (http://www.maccactus.com/cereus%20peruvianus%20column.html)
It isn't normal for the top to fall over like that. That problem is caused by one of two things. The first and most likely is that it is not getting enough light.

Generally, the closer a plant gets to the ceiling, the less light it will receive. The other reason may be too little water. Make sure the soil dries out between waterings, but soak the soil good when you do water. Obviously since you've had the plant for 11 years, watering probably is not the issue.

You can prop up the portion of the plant that has fallen over, but moving it to a brighter location will help, especially if you have a skylight. Good luck.

Sincerely,

Greg