Al, 40F is a minimum temperature typically used. My max/min in the garden has barely been that low so far this year. Some growers use 45F or even 50F, depends on what you're growing and how much money you've got to burn :) Toni-Marie, doesn't everyone have one of these? They're so easy to grow and propagate, mine drops pups if you say angry words to it. Larry, Mammillaria vetula ssp gracilis 'Arizona Snowcap' to give it the latest full name. Its a monstrose form of the regular M. gracilis, pups madly into a jumble of fuzzballs. It grows pretty fast, its incredibly tolerant of low light, overwatering, and this one came from B&Q, I think.

hi - I have only recently become interested in mamms...and now there are so many i would love to collect. But, alas, I am limited by my indoor growing space! that's the problem with buying a new book on Cacti/Succulents...it becomes a shopping list for new plants that you don't have enough room to add ;-(. I just finished reading 'Cacti and Succulents: An Illustrated Guide to the Plants and their Cultivation' by Graham Charles...now i want to collect everything in it! Tom

I'm a little curious to know how your plant #4 is doing, M_Medina, as my friend is having similar problems with his fuzzy plant (leaves getting yellow and falling)... What did you repot your plant in? Is it better now? I would have liked to help with you questions regarding the roots, but I am too new to plants for that; I'd say they look okay although they do seem short... and too compact? Actually, it looks like a cutting that is growing roots... but someone else might know better!

I'm no expert but I love how your cactus looks. Looks healthy to me. I think the bottom part is corking and comes with old age. I use old face towels to hold my spiny guys. Fold until it's thick enough to not get to your hand then hold him while you clean the roots. For root cleaning I use a blunt stick (Starbucks wooden coffee stirrers) and gently poke while gently pressing the soil in my hands and having old soil fall off into a garbage bin. Slowly slowly repeat poke, squeeze root ball.. until most of the soil is gone. I would choose one size pot up, and of course, the usual "gritty soil" that everyone here talks about. Mine is about 70% pumice and 30% soil mixed well. Hold the cactus over the pot, in the middle, then slowly pour the mix into the pot via the sides using a spoon. Make sure the cactus is not potted too deep.. Just where it was before.. And make sure potting mix goes to the TOP lip of the pot (not less because water might pool there). Then leave him in his usual spot with his new soil and water him after a few days. That's what I would do. Good luck!