Hello, About 1.5 months ago I purchased about 15 small cactus and succulent plants from a flower shop that was going out of business. Most are doing quite well - I'm in the process of identifying them. BUT - one that I haven't been able to identify yet has begun losing its nice dark green color and is fairly rapidly turning light green/yellowish from the top down. There is also a lot of whitish fuzzy stuff that seems to be accumulating at the very top that I didn't notice before now. I have watered it one time. I used regular tap water. It is living inside and receives direct sunlight for about 5 - 6 hours a day and bright, filtered light the rest of the daylight hours. This is what the cactus looks like: It's a single column about 4 inches tall; it has 8 distinct vertical spines that are covered with fairly large needles that are clustered. The needle clusters are in starburst type forms that are regularly located the length of each of the spines. Whatever help anyone can give me about how to stop this change that appears to be 'bad news' for my plant will be appreciated. Many thanks.
really need to see a pic of it!! some cacti have white fuzz and it's totally normal and to be expected...other times the white fuzz isn't part of the plant and is actually mealy bugs. from your description, i'd say it's a mealy infection and i'd segregate that plant from the others so that they don't spread. treat with q-tips dipped in rubbing alcohol and touch to the white fluff...that will immediately kill the bugs...use a fresh swab (dipped in the r-a) and then rub all the crevises well (to get any eggs) and then treat again in 10-14 days and check it again in another 10 days or so and treat again if you need to. also check all other plants for infestation. at the first sign of 'fluff' pull out the q-tips and rubbing alcohol again.
hard to say with pics. if it get really bright sun for so many hours, it could be due to "sunburn" and with it being spring (more and stronger sun) its possible. is it mushy? some forms of rot are light coloured. this may help: http://kadasgarden.com/Csick.html
Thanks for your responses. I don't have a camera to photograph the cactus but this might help you visualize what it looks like: When I look at it from above, it looks just like a star anise seed with 8 spines or pointy parts. I've also looked more closely at the fuzzy stuff at the top of the plant. I don't believe mealybugs are the problem - I've had encounters with them before and this stuff is different. In fact, I pulled some of it off with tweezers and it looks like short pieces of hair that is around 1/4 inch long. I'll see if I can get a camera and post a photo. Thanks again!
is it coming form where the spines come out (areoles)? if so this is probably normal wool form the new growth!
My San Pedro that I received in the past couple months looks similar (single column, 7 instead of eight vertical spines, star shape if looked from above, oh and mine's eight inches) and has light green on the top as well. For my cactus, this is new growth! This growth (top two inches) gets light to dark from the top to bottom. Maybe its the same for you? Hope this helps and hope your cactus is doing well!
Spines? Do you mean the ribs that run vertically along the body? I have never seen a cactus with needles on the spines, hence my question.