Rooting a mammillaria from a top cut

Multiplying your cacti vegetatively.
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loyall
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Re: Rooting a mammillaria from a top cut

Post by loyall »

greenknight wrote: Fri May 06, 2022 8:42 am Yep. Don't give any water until roots start to grow. You can just pull it up and look - but if there's resistance, don't pull it up, it's rooted down. Water very shallowly when it first roots, gradually give more as the roots go deeper. Caution is the key, better to under-water than over-water.
I don't understand why it is so critical not to water. I have been successfully growing the mother plant for over a year with regular watering. I got a lot of blossoms so I must have been doing something right. This novice thinks that the cutting will send out roots seeking water. Why isn't it good for the roots to find moisture quickly? Doesn't the callus protect from rot? I would think that the amount of moisture in the soil mix is mostly a function of time lapse evaporation, rather than absorption by the plant. So why not water the cutting as if it were a rooted plant?

Also, pulling the cutting up to see if roots are forming seems a bit reckless. I question if newly forming rootlets will create enough resistance to be noticeable, particularly since they may not be very long or strong.
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loyall
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Re: Rooting a mammillaria from a top cut

Post by loyall »

jerrytheplater wrote: Thu Apr 28, 2022 7:03 pm Many ball shaped cacti will grow pups all around the top of the plant at the areoles. Let it grow and you may be able to cut off a bunch of new babies next year.
Except that due to space limitations I do not want a bunch of new babies. What I might be interested in is if the mother plant developed into an interesting specimen by either pupping around the base, which I don't think this species in inclined to do, or multiple pups around the apex were strong enough to support themselves in an aesthetic way. How long do you think I might have to wait to see what the mother plant produces, if anything. I am debating whether to wait, and for how long. Even if my cutting should fail, I don't see how I could get a second cutting from the mother plant unless I wait to see if it pups. Pardon my mental musings over a not-too-valuable plant.
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greenknight
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Re: Rooting a mammillaria from a top cut

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Evaporation is only a minor factor in drying the potting mix, absorption by the plant roots is what mainly does it. When you water deeply, the mix in the bottom of the pot becomes saturated, as explained here: http://gardening.stackexchange.com/ques ... ater-table

In this saturated layer, water fills the pore spaces so there's no air. If it remains that way due to no roots to take up the excess water, soil microbes will use up the dissolved oxygen. Anaerobic bacteria will then grow (the soil will go sour), it will become a kill zone for the cactus roots, when they reach it they will rot.

Roots will form without moisture present, they grow in response to gravity. They'll even grow if the cutting is suspended in the air as Tomek B. describes (Yes, that method does work).

The first roots that grow won't be fine feeder roots, they'll be thick primary roots which have a tough cap on their tip to protect them as they penetrate the soil. They don't cling to the soil, they actually produce a slimy secretion to help them penetrate the soil. They're not fragile, picking the cutting up won't damage them. After a time, secondary roots will grow behind this growing tip, and these will grab on to the soil - if there's just a little of this, some soil will come up with the cutting when you pull it up. If you check it frequently, though, you'll see the primary roots growing before there are any secondary roots.

You can leave the pups attached to the mother plant and it will make a nice-looking clump. You'll always have the option of propagating them later - bigger cuttings are better.
Spence :mrgreen:
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loyall
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Re: Rooting a mammillaria from a top cut

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Thank you, Spence, for the clear explanation of rooting behavior. I should call you teacher. How much sun exposure should I give the cutting?

As for your comment on my reply to Jerry, you said "You can leave the pups attached to the mother plant and it will make a nice-looking clump." Yes, but M microhelia don't generally clump, or do they? I fear pupping on top would be unstable and unattractive. That is why I was thinking better to save the effort and toss the mother.
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jerrytheplater
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Re: Rooting a mammillaria from a top cut

Post by jerrytheplater »

Loyall

Most of my experience with cutting off cacti has been on Sulcorebutia or Rebutia. I may have done a Mammillaria. But, I do remember seeing photos of Frailea in habitat that were eaten by goats down to the ground which grew back by pupping and were now multi-headed. In each case, the plant produces multiple pups around the cut surface which will crowd each other out over time. The scar on the original plant will be visible. The plant will not look like a typical example. I cut off all of the pups to root them when they are big enough. And that might be a year later. I don't let the looks of the plant bother me, but that is a personal call.

There won't be any instability as in the plant falling over due to imbalance with the growth of pups.

It is your call what you want to do. If you have the growing space, you will not have any extra work to allow the original cut off plant to continue to grow and produce pups if you want them to multiply what you have to maybe trade for other plants, or as insurance against failure of the cut off top piece.
Jerry Smith
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45 inches (114 cm) rain equivalent per year, approx. evenly spread per month
2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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greenknight
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Re: Rooting a mammillaria from a top cut

Post by greenknight »

Mammillaria microhelia doesn't always remain solitary, it can form clumps naturally - this page shows one such specimen:http://www.llifle.com/Encyclopedia/CACT ... microhelia

Its columnar growth habit insures that the offsets will soon hide the scar - it will look fine. Pups will start growing right away, growth should be easily visible within a few weeks.

Best to keep the cutting in bright shade until it roots, no direct sun.
Spence :mrgreen:
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BryanT
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Re: Rooting a mammillaria from a top cut

Post by BryanT »

Hi loyall,
Like Jerry and Spence said, M microchelia do grow pups. They don't grow very big, so won't need lot of space.
Here is the picture of one of mine.
Mammillaria microhelia.jpg
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Bryan
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greenknight
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Re: Rooting a mammillaria from a top cut

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Nice one, Bryan!

This is what columnar Mamms all do when they get tall, they flop over and grow prostrate. They have no woody structure to support them.
Spence :mrgreen:
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BryanT
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Re: Rooting a mammillaria from a top cut

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greenknight wrote: Sun May 08, 2022 10:48 am Nice one, Bryan!

This is what columnar Mamms all do when they get tall, they flop over and grow prostrate. They have no woody structure to support them.
Yes Spence, they all do.
Some people use support for them to stand up, but I just let it be, and possible less pressure on the soft base, better for the plant. I think they look good in a rectangular pot. Might do that next time re-potting.
Bryan
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loyall
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Re: Rooting a mammillaria from a top cut

Post by loyall »

Great. Thank you Bryan and Jerry and Spence. I feel well informed now on M microhelia. I believe mine is more precisely M microhelia var microheliopsis with rosy striped blossoms.
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greenknight
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Re: Rooting a mammillaria from a top cut

Post by greenknight »

Could be - the difference is pretty minor. They were formerly considered separate species, which I though was silly.

You can actually tell when rooting has begun without pulling the cutting, new spines will begin to grow at the same time as roots do. It doesn't hurt to pick it up once a week or so and inspect the base, both for roots and possible rot - while the callus layer is pretty rot-resistant, it's not totally rot-proof.
Spence :mrgreen:
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loyall
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Re: Rooting a mammillaria from a top cut

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Hey Spence, Three weeks now since I topcut the M microheliopsis. One week suspended vertically, and two weeks siting on substrate away from direct sun with no water. I lifted it today, and no roots yet. Any thoughts? worries?
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Aeonium2003
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Re: Rooting a mammillaria from a top cut

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I wouldn't worry.
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greenknight
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Re: Rooting a mammillaria from a top cut

Post by greenknight »

It's early yet, have patience.
Spence :mrgreen:
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loyall
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Re: Rooting a mammillaria from a top cut

Post by loyall »

Cutting - Four weeks and no water no direct sun no roots.
Moher plant - Water, fertilizer, full sun, and no signs of growth.
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