Help needed - Mammillaria Schwarzii

[Nory]

I bought a small Mammillaria Schwarzii in about March 2018 - at the time it looked like this:

I had it on a south-facing windowsill and it grew very quickly. I tried moving it to a less sunny spot on a west-facing windowsill but it continued to grow regardless. The flowers died off and haven't come back since. Now it's over double the original height and it's also got a lot of new(er) growth. The photos below were taken in November 2019:

I have no experience of growing cacti - I actually tend to buy them for their relative low-maintenance.... None of the pictures I've seen of Mammillaria Schwarzii look like they're this tall, so can anyone suggest what I should do with mine? So far I've just left it alone because I have no idea!

Is it best to leave it as it is and wait for it to even out? Or should I be removing the shoots and planting them separately? I'd love to have my small flowering version back - or a clump of them, either way.

Any help would be much appreciated!

[esp]

I had it on a south-facing windowsill and it grew very quickly. I tried moving it to a less sunny spot on a west-facing windowsill but it continued to grow regardless. The flowers died off and haven't come back since. Now it's over double the original height and it's also got a lot of new(er) growth.

It looks basically healthy as though you are watering it appropriately but it is etiolated (stretched) due to too little light.
Grown on a windowsill, this needs as much sunlight as possible. It may grow quite quickly in summer in full sun and produce rounded, compact healthy growth. If it is kept warm but well watered, and with less light, it will continue to grow but with weaker, thinner, growth that you are getting. In particular, try to keep it cool over winter when there is less daylight- a windowsill over a radiator is a prime location for getting this weaker growth.
A cool winter rest, with less water, is required for many cacti to flower the next spring or summer.

So - if you can move it back into a south facing window, not over a radiator and reduce the water a bit for the next 3 months or so.

[Aiko]

It is very badly etiolated. The reason for it is too less light (you moved it away from a sunny spot!) and continuing watering it in (probably) a warm room. Warmth + water = growth. And growth will be very very very poor in bad light conditions. Usually winter has very bad light levels, so it is best to withhold water between September and March, and keep the plant in a nice cool place like an unheated room.

When in growth, from March onwards, move it to the brightest spot you have. If you want it to grow less fast, water it less often.

It will not easily get unetiolated. Expect the disturbed growth to be visible for a very long time. But you might expect flowering to return at some point. Maybe. Depends on how you take care of it.

[Diane]

I agree with everything Aiko has written. It is very etiolated due to lack of light. To show you how it should look, I'll show you my very old plant, which is grown in full light in my greenhouse. Unfortunately you won't be able to replicate these conditions on a windowsill.

Mammillaria schwarzii

[Nory]

Thanks everyone, this is really useful. When I saw how quickly it was growing in the full sun (and so soon after I brought it home) I panicked and hoped a bit less sunlight would slow it down! But you're exactly right, the room was still extremely warm. Not any more though!

Would it be possible to remove one of the shoots and try growing a new one from that, without damaging the original plant too much? If so, how would I need to go about it...?

[Nory]

I agree with everything Aiko has written. It is very etiolated due to lack of light. To show you how it should look, I'll show you my very old plant, which is grown in full light in my greenhouse. Unfortunately you won't be able to replicate these conditions on a windowsill.image.jpg

Also Diane, this looks amazing! So so pretty!

[NickHitchcock]

That's a beaut Diane.

[habanerocat]

Would it be possible to remove one of the shoots and try growing a new one from that, without damaging the original plant too much? If so, how would I need to go about it...?

Leave it dormant now until March. You'll need to repot it into a 50/50 compost/horticultural grit mix. When repotting remove as much of the old compost as possible. When doing this it will be easy remove an offset or two. Some might even have roots. If not, just let them dry out for a few days before repotting.

[Nory]

Thanks habanerocat!