Ten days ago I purchased a 40" Saguaro (Gigantea Carnegiea) from a nursery here in Tucson, Arizona. I let it lay in the shade for two days with Sulfer powder on open roots then planted it without adding water. In the nursery it was bunched together with many other Saguaros and was probably partialy shaded at various times of the day. On my property it is in an all day full sun location. I oriented it North at the nursery and here with a compass. Could these dark bloches halfway up the cactus be signs of sunburn and if so what with and how long should I cover it? See pic. The wound was treated with Hydrogen Peroxide. For faster results, please respond here or to larmus@gmail.com. Thank you.
Doesn't look like sunburn to me - more like something took a little chomp out of the cactus. H2O2 should disinfect it, but I wouldn't be too terribly concerned about that. It should scar over and then, no more problems. Best of luck
