Question

Sick Barrel   QUESTION: Hi, i live in south florida. Many of my barrel and small round cactus have problems. It starts with a discoloration at the bottom of the plant. They look light tan. This slowly creeps up over time, with the tan replacing the green. It might take two years. I dont think its a water problem because some of them are in pots with very little dirt, some are in the ground. But i could be wrong. I also do not fertilize regularly. Thats kind of what i was thinking it was. My opuntias get cochineal scale but that has never attacked the barrels. I am putting in a new bed for succulents. It will be 3' over grade so it should drain great. OUr dirt here is crap, almost plain sand which i think would be good for them. Might be a little alkaline though since we sit on limestone here in Florida. The attached pic shows a 10" barrel i pulled out of a pot. The brown creep is almost all the way to the top. ANd my others in the ground look the same, making me think its diet is wrong. Any help appreciated. Thanks!

ANSWER: When your cactus develops the tan exterior does the cactus die?  When you pulled the plant out of the pot were the roots healthy? If so, I don't think the problem has to do with nutrition (cactus, for the most part, don't like fertilizer).  If you could answer these questions I could help you more.

Maureen

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QUESTION: Maureen, one final pic. This is an opuntia. It went downhill just like the barrels. But the odd thing to me was that you will notice a little bud, a new pad emerging, even though it is in trouble.

Answer
Sorry I've been so slow in responding.  I have been looking at lots of pictures and reading and talking to other cactus folks.  My initial reaction that hasn't changed is that it's not a nutritional problem, but rather, environmental.  I wouldn't attempt to grow cacti in South Florida, except for the epiphytic type.  The climate just isn't in keeping with their needs. They do best with dry air, a long period of dormancy without water and in cold temps.  I know S. Florida can get quite cold in the winter but that weather isn't prolonged enough.  The bottom line is that I do think your cacti have a fungus, not the black rot that is most common, but possibly dry rot that is tan and overtakes the plant.  Given your climate, I think you will keep having this problem and trying to treat it will be a losing battle.  You may do better with succulents as they can tolerate a more temperate climate, and grow your cacti indoors.

There is The South Florida Cactus and Succulent Society and you can find them on line. I recommend you get in touch with them. I'm sure they will be able to tell you what will do well there. Also, there is one Opuntia humifusa that is indigenous to Florida and you might have less problems with that.

The consensus has been, too wet, too humid, too warm.  I wish I could give you better news, but thanks for the challenging question.  If that society gives you other advice, I'd be curious to know, and thanks for the fascinating pictures.  The prickly pear one didn't come through, the barrels did.

Again, sorry for the delay but I wanted to get as much info as i could.

Maureen

How did you make out?  Did you call the society?  The more I cna learn about cacti growing in other regions the happier I am.

Maureen


Dear Mike,

I am just wondering how you made out with your cactus?  Did you getting touch with the C&S Society of South Florida?  What did you end up doing?  I don't get many questions about desert plants in South Florida and would really appreciate anything else you found out.

Thanks,
Maureen