Q. I bought 3 cacti about 8 years ago and don’t know their variety. Most tall cacti I see around town are very old Saguaros. The biggest one towers over the cactus garden at nearly 12′ high growing over a foot per year! Can you identify them? Also the photos show problems that I hope are cosmetic. By the way, I have never wrapped them to protect from the frost and now they are just too big to reach. Do you know how tall this kind of cactus get in Las Vegas?
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| Cactus with blemishes. Not that it is on older pads and stems, not the newer ones indicating that it was probably caused awhile ago and the newer growth appears to be fine.
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A. For identification of cacti I would get hold of the local cactus and succulent society in Las Vegas. I am not a huge fan of wrapping saguaros during the winter. I believe this causes more damage than it does good particularly if we have a wet winter. Note that the discoloration occurs on some older pads and stems while the newer growth doesn’t have it. Whatever it was happened at one point in time and is not affecting it anymore.
I’ve seen them wrapped in burlap here and personally believe this is a mistake. One wet winter when they were unwrapped they were covered in surface blemishes, perhaps bacterial necrosis from having wet burlap in continuous contact with the plants surface.
A certain amount of scabbing or blemishes are going to occur and all plants and should not be a problem if the plant is healthy enough to contain them. You might want to consult http://ag.arizona.edu/pubs/diseases/az1124 for more information.