Rust/orange coloured spots on cactus?

[oxygene]

Hello all,

I bought two small (2.25" and 3.5") cacti from a grocery store (!) last week. Some of them looked a little unhealthy so I thought I might be able to save some of the better looking ones, even though I am a total cacti newbie!

One of the plants, labelled as a mammillaria pringlei, has some strange rusty/orange coloured spots. The largest spot is on the top of the plant and the spot looks somewhat withered. There are some other small orangey spots on one side of the cactus. I tried to take some pictures but I found it hard to focus on the orange spots and not the spines:

cacti 2.jpg (129.82 KiB) Viewed 4859 times

cacti 3.jpg (57.57 KiB) Viewed 4859 times

cacti 4.jpg (56.39 KiB) Viewed 4859 times

I have not transplanted or watered it yet. Are these spots harmful to the cactus, and if so, how would I be able to fix it?

Thanks!

[greenknight]

This might be damage that's already healed. It it's dried up, not mushy, that's probably the case.

The only way to get rid of this would be to cut the plant off below the level of the damage.

If the damaged spots seem to be dried up, I'd put off cutting it. Go ahead and repot it, as explained here: http://cactiguide.com/forum/viewtopic.php?f=25&t=9222" onclick="window.open(this.href);return false;

After potting, give it plenty of time for the roots to heal before watering. Keep an eye on those spots, if they are spreading you'll need to do surgery.

[oxygene]

Thanks! The orange spots look dry and not mushy.

I read the link and will definitely repot it and the other cactus, which I believe is a mammillaria spinosissima. They both came in 2.5" inch pots - the only new pots I have now are 3" clay pots. Are those too small for the cacti?

I have a few other questions about soil and repotting, but I'll post those in a new thread later in the proper section.

[greenknight]

3" pots will do for now. Clay pots are not really the best, but in another year you can repot again since they should grow into those quickly.

I do think this one was correctly labeled - listed here as Mammillaria rhodantha subsp. pringlei, however. Looks like it was a bit light-starved - if you move it into direct sun, do it gradually to avoid sunburn.

[oxygene]

Thank you!