Mammillaria Hahniana has white spores at base

[hairylady]

Hi I'm new to this site and forum,

I have a Mammillaria Hahniana, better known as "old lady cactus." I received it in July and am now noticing white spores forming at the base. I feel I may have overwatered causing it to rot or form fungus. I'm new to keeping cactus indoors, but have some outside in my garden. I'm tried to upload a photo to get a proper diagnosis and even resized my images, but it's saying, "sorry, the board attachment quota has been reached" which is confusing because I haven't attached anything. Thank you cactiguide community for your help.

Sincerely, Hairylady

[george76904]

The entire board is full and right now no one can actually upload photos. Most people here use something like Flickr to host their photos. Unfortunately I am not positive what you are referring to when you say white spores. The cactus it is probably dormant right now but we don't know the area where you are so its hard to say exactly.

[hairylady]

okay I can upload my photo to Flickr and I live in Southern California, but it's an indoor plant.

[hairylady]

Here is my photo album of my cactus on Flickr:

https://www.flickr.com/gp/137001016@N02/na107u" onclick="window.open(this.href);return false;

[esp_imaging]

That just looks like a mineral deposit from the water, and/or from the compost. It doesn't look harmful in itself, although it may indicate that your water has a lot of dissolved material in it.
Your compost looks rather soggy! Does the container have a drainage hole so excess water can drain out? If not, it means that any dissolved minerals in the compost will eventually form a crust on the surface as it dries, which may be what you are seeing. A drainage hole will mean that at least some of this may be washed through the pot.
Is the compost itself very well draining, and are you watering appropriately for your local conditions? Mammillarias in the northern hemisphere should generally be kept rather dry at the moment, they will be happy with almost no water during the winter, unless they are kept somewhere quite warm.
Have a read through this cultivation guide and ask any further questions: http://www.cactiguide.com/growcacti/" onclick="window.open(this.href);return false;

[hairylady]

Oh thank you so much! That helps a lot. I tried removing the white deposit (?) with an end of a q-tip so I hope that helps. I'm going to move it into a bigger pot that can drain easier as well. I am using Miracle Grow cactus/succulent soil. Sometime's it's really hot here in Los Angeles and sometimes it's cooler, but mostly it's warm. During the summer it didn't have trouble draining, but now it seems to be retaining water. Yes the water I generally use is from the tap and we do have hard water. However, as of late I had been using arrowhead water from a small bottle before the deposit formed.

I'm glad it doesn't have rot or fungus! I'll take a look at the guide and update here if anything else happens.

Thanks!!!!

[george76904]

Another thing, it may be an old lady cactus but it is not mamm. Hahniana. My guess it the "Peruvian old lady" espostoa melanostele. But I would agree with the post esp_imaging made it is sound advice. Some here on the forum acidify their tap water to avoid deposits, you can use the forum search tool to see specifics on that. Miracle grow cactus mix works OK. Most people on the forum here tend to either mix their own, or accent things like miracle grow potting mix to make it a littlebetter for our spiny friends. Like adding more pearlite for better drainage type thing. Lots of great mixes to be found on here.

[jmoney]

I'm not positive but that ceramic pot probably doesn't drain that well. There needs to be holes in whatever pot you use for the cactus. If it doesn't drain, then it will be detrimental to the health of your cactus.

[hairylady]

Oh I see. I wasn't sure what type of lady it was, but it is a lady fellas. I am in the process of looking for a better pot and mix so I will definitely use the tools I learn from this site to help my little friend.

P.S. I edited my flickr album so the proper name appears. I'll post more photos soon to show you my results from repotting and the change of water.