Beginner Gardening: Caring tips for Bristle Brush Cactus?, 2 by sidedish

sidedish wrote:
Hi everyone!

I recently bought this Bristle Brush Cactus (Mammilaria pilcayensis) for a class assignment (have to take care of a plant). I picked it up because I thought a cactus might be easy to take care of it, and I thought my location, sunny California, might be a good fit for it. I was immediately taken in by the web searched images of its blossoms-- such a cute ring of flower crown! So, although I go this cactus as an assignment, I really hope it\'ll live long past this class; I want to take good care of it and hopefully see it boom next year! I\'m new to cactus caring so would love to receive some caring tips!

So far, I\'ve read through this page http://davesgarden.com/guides/pf/go/95804/ and looked around at some of the general info on this plant ... but I\'ve never had a cactus before so am wondering if there\'s anything specific that I should keep in mind while caring for this fella?

I currently keep the cactus on my window sill, and my window is more or less northwest facing; I think it should receive enough sunlight? Also, I read that it needs to be protected from frost? What does that mean, exactly? What degree is that?

But oh, my main concern right now is if I should repot this fella? It looks kinda like a tight squeeze in the current plastic pot, but I have no idea if it really is? And I\'m afraid of messing it up! Also, I\'m not sure what type of soil to get for it? I read \'cactus soil mix\' but... what exactly is it? Is it purchasable somewhere? Or do I have to mix it myself? I\'m rather new to plant caring and feel like I\'m fretting over everything!

Also... I\'m thinking about getting another plant to go with it (if repotting), is that a good idea? What are some good companion plants for this cactus fella? Or should the cactus just remain solitary? By the way, the cactus is about 2 inches tall.

Any help would be much appreciated, and much thanks in advance!