Question
Hi Greg:

We live in Central Florida and 2 years ago had a cactus garden planted by a professional horticulturist in the front of our house which has a southern exposure. Everything seems to have thrived except now we notice that our 3 Cereus cacti plants, which are about 5 feet tall, are starting to turn yellow. They are still firm and produced good fruit this year and beautiful flowers. With the exception of the yellow discoloration, they look good, but I would like to know what is going on.

My husband recently applied a 10-10-10 fertilizer which was recommended by someone in the garden shop at Home Depot, but we have not noticed any change in color.

I really don't want to lose these beautiful plants. Any suggestions would be most appreciated.

Eileen Allard

Answer
Eileen,

Generally Cereus do that in response to heat & drought. They are not true desert cacti so they do not do well in severe drought. I live in the Phoenix area and that is a fairly common sight. The fertilizer was a good idea, but it can take weeks to make a change. If you have been getting rain, that should help. Cacti seems to respond well to nitrogen, which is dissolved in rain water. If not, try a fertilizer with a higher number for nitrogen.

Hope this helps.

Sincerely,

Greg