I have this mammillaria hahniana:

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I'm considering repotting to another container, which is more beautiful, more stable, wider and shallower. You don't see it but there is a drainage hole. Here it is:

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My mammillaria is probably going to flower, as it grew some buds:

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Considering the time of the year (spring is coming) and the size of the plant compared to its pot, would you repot it now? I'd like it to produce pups but I'm afraid the current pot is too small for that. Also, when I look under the pot, I can see roots going through the drainage holes. Do you think this bonsai container would be appropriate? Could the repotting prevent the cactus from flowering? Should I wait for the flowers to be gone?

  • 2
    It's more likely to flower if it's under a bit of stress than if it's got a huge amount of space to spread its roots into. So don't water it at all until you can see it's really starting to grow and/or the buds are really developing, not just sitting there. The only thing I would consider (at least for the next couple of years) would be repotting it in the original pot and move it closer to the middle, not wedged against one side.
    – alephzero
    Feb 28, 2017 at 2:35

2 Answers 2


Cactus plants should only be potted into something larger when they've absolutely filled the pot they're in already, and then only potted into something one size larger. It looks to me as if the attractive bonsai dish would hold at least twice as much soil as the original pot, though its hard to be sure. If so, that's just a bit too much free soil for your cactus to thrive.

Its probably best to wait till its flowered, then pot into a pot that's only one size bigger, then move into the green bonsai dish the next time you need to increase the pot size. If you can find a pot that can sit inside the bonsai dish, then you could just stand the cactus inside it in a pot till its big enough to repot again. The other option is to buy another cactus and pot the two together into the bonsai dish. More info here on when to repot http://www.cactusnursery.co.uk/potting.htm

  • What's the reason why a cactus shouldn't be in a too large container? Is this because the soil takes longer to dry, leading the roots to rot, or is there another reason? Anyway, I like your last option, I may choose another species of Mammillaria to go with this one.
    – Augustin
    Feb 28, 2017 at 21:08
  • It's mentioned in the link, pot size, but the reason is the same for whatever plant you're potting - one size up at a time is always best, because otherwise there's too much unoccupied potting medium which may 'sour' and become toxic to the plant, plus the roots tend to wander and not form a good rootball.
    – Bamboo
    Feb 28, 2017 at 22:12

I love the bonsai pot...as long as it truly has a drainage hole. Lift the bottom of that pot off the saucer with rocks or tiles at least 1/8 to 1/4" to increase drainage. Use potting soil...potting soil for cactus is fine. No additives like water gels or sponges or even fertilizer. It might delay the flowering a bit but shouldn't be a big deal. Do not fertilize, now. When you do use an extended release and only a tiny bit. Lovely use of a bonsai pot!! Oh and when you water do not use tap water if you are on city water...get bottled or distilled water.

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