eccles Posted September 24, 2002 Hi there - many of my cacti have been developing black lumps under the skin and I don't know why!! and a few have really lumpy (REALLY LUMPY) skin around them!!! Is this some kind of dissease? what should I do? I'd hate to lost my cacti Please help if you can. thanks!! Share this post Link to post Share on other sites
Guest Mesqualero Posted September 24, 2002 Definitely sounds like some sort of rot.. do a google search for possible treatments.. but If you have a C&S society near you maybe you could ask a member there. Share this post Link to post Share on other sites
spiraleyes Posted September 24, 2002 have you sprayed anything on them at all? Share this post Link to post Share on other sites
eccles Posted September 24, 2002 um... yeah I sprayed on pyrethrum because a friend said some had scale... and that's what you use... nah I don't think it could be rot - they are small... (on some)... it just doesn't look like rot. perhaps they don't like pyrethrum... Share this post Link to post Share on other sites
spiraleyes Posted September 25, 2002 thought so, my friend sprayed the same on his t.p.'s . came up in big nasty black lumps and welps. horrible looking dis-ease. hope yours arent to bad. he tried to cut it out but.....it was messy. Share this post Link to post Share on other sites
Torsten Posted September 25, 2002 pyrethrum is extracted as an oil and usually used in suspension. Once sprayed the oil spots can cause cacti to rot (especially in winter). Keep your cactus REALLY dry. Do not water, and especially do not let it get wet on top. Dust the black spots with a little elemental sulphur dust. if the rot progressed after this you may need to cut it out and dust again. main thing is to keep it VERY dry. Pyrethrum is not very effective for scale. And oils can't be used on most cacti. The best option is to simply scrape them off. Share this post Link to post Share on other sites
eccles Posted September 25, 2002 thankyou all for your help!!! the hardest hit parts of them seem to be mainly the new growth areas. on one of them it is a pretty tragic sight, but the rest are pretty small, and there are only 2-4 spots per cactus. and thankfully I didn't spray all of them... something restrained me from doing it to the best of them... (I didn't feel good about it at the time because I thought it could hurt the spiders who like to live on them!) anyway... I guess I will need to find some sulphur from somewhere! Share this post Link to post Share on other sites
Torsten Posted September 25, 2002 Originally posted by eccles: I guess I will need to find some sulphur from somewhere! Most garden stores have it in bulk, but for small applications you can simply buy food grade sulphur from your local chemist. Share this post Link to post Share on other sites
