De-Grafting

[DaveW]

How do you de-graft the more difficult cacti? I am thinking of plants like Aztekium ritteri and Mammillaria luethyi which are often obtained on grafts, but few of us are successful at de-grafting when large enough and rooting down. Do the Continentals or Japanese manage it and have some tips for us?

I was told you should not cut off a grafted plant at the graft union since the vascular bundles are too lignified to root easily there, but leave a centimeter or so of the scion on the stock, which will usually produce more offsets for propagation anyway and then root down the top. These de-grafts will often dehydrate with me before they put out roots.

OK with plants that tend to be of an elongated shape, but with more disk like shaped plants like Aztekium ritteri it is not easy to cut them off far above the stock. Is the only method in their case to "blind" the grafted plant and then root down any offsets produced? You can cut them off leaving just a stump of the scion and bury that, but most would prefer the scion itself to be rooted down.

I would be interested in any tips on de-grafting and rooting down these grafted plants that are either slow to raise from seed, or seldom available on their own roots.

[RICHAUD]

de grafting a Mammillaria luethyi why not
but an Aztekium ritteri the chance to put roots are near 0 %

[ralphrmartin]

I've successfully degrafted Yavias. They grow much more characteristically on their own roots. Also Mam. luethyi.

It helps to start with grafted seedlings with a narrow neck near the base of the graft.

Treat them like other cuttings...

[Tina]

Hi Dave,
Its a bit late in the year to start this so would it be next years project ?.
What stock is it on ?
Talking to Stirling baker once he cuts to a shorter stump & pots up, I have done this a few times & the plants seem fine sometimes when you repot later the graft has died & the scion puts roots thru the debris or the plant slowly dies.
I also have an old pereskiopsis graft I buried which still sends up a stem every year even though the plant is large now 5" pot & lives in the cooler greenhouse.
Sometimes you are better off using the grafted plant as a stock plant for offsets,this works well for Euphorbia . I have tried rooting Aztekium offsets but it didn't work but a hylocereus grafted plant I chopped down is starting to look good.

Its trial & error but all good fun.

[Tony R]

...this works well for Euphorbia ...

Perhaps David should practise on some euphorbias before he tries the real thing!

[IanW]

Hi Dave,
Its a bit late in the year to start this so would it be next years project ?

I actually often find this is exactly the time of year to do it - it becomes cooler so they don't dry out without roots, and they have ample time to try and sprout roots ready for the next growing season.

Each to their own of course, but I find if you have stuff rootless in the summer it's more likely to dry out and die.

[DaveW]

No not tried it on my present grafts yet Tina and would not at this time of year, or until they are larger. I tried it a couple of years ago though. One was a suffering Aztekium ritteri from a friend who died that had formed a flat disk like clump about two and a half inches across on an ailing Pereskia stock which was about the thickness of a pencil. The stock had started to deteriorate so I took the scion off but it just gradually shrivelled and dried up rather than rooting.

The other was a Mammillaria luethyi. These after a few years have always seemed to eventually shrivel on the stock in winter for me, though the stock still remains healthy. I sometimes wonder if it is differential shrinkage between the stock and scion in the dormant season that breaks the union? Anyway attempts to root M. luethyi down also failed.

I think you might be the right person to ask Tina, since I am also going to ask our Chairman who was concerned with tissue culture. Would it be possible to try rooting these de-grafts in something like the agar gels you use for tissue culture rather than on soil? They seem to be able to grow plants from almost single cells by that method, so I wondered if they could be used to produce roots on de-grafts?

I would probably try rooting offsets if the scions produce them, but sometimes you need to root the scion itself, ideally leaving some on the stock to offset, but that is hard in the case of the disk like A. ritteri. Of course the purpose of the graft is to get a large plant quickly and just removing offsets to root down rather defeats that object since you are more or less starting from scratch again.

Searching the web I found these:-

http://davesgarden.com/community/forums/t/1242512/

http://forums.gardenweb.com/discussions ... ing-medium

http://www.nugel.co.uk/

http://www.nugel.co.uk/component/content/article?id=84

Reading some of the above concoctions perhaps I should try Polycell Wallpaper paste as a base gel as they used to use for setting seeds The chemistry is beyond me so what would actually be required would help?

https://www.allotment-garden.org/garden ... rmination/

I know of the leaving the stump of the stock method and burying it. Which often works with the plant eventually rooting down through a deteriorating stump, but in some cases the stock seems to endure and still provides the roots. The reason I wanted to root down directly in cases like Mammillaria luethyi with tuberous rooted species was I wondered if the reason the rootless scion tended to shrivel on the stock was it was one of those plants in habitat where the top growth tended to largely degenerate in the dry season and regenerate again from the tuberous root when the rains came? Therefore I would like the plant on it's own tuberous root.

Interesting Ian, the cooler weather may stop them dehydrating but does it encourage rooting before the warm weather returnns?

As to Stocks, the Aztekium ritteri and Mammillaria luethyi are on Trichocereus spachianus.

"Perhaps David should practise on some euphorbias before he tries the real thing! "

Good idea Tony you would not bother about loosing those.

[IanW]

Interesting Ian, the cooler weather may stop them dehydrating but does it encourage rooting before the warm weather returnns?

Honestly, I have no idea, but I do know that when I find plants without roots I just whack them in cat litter over winter and usually end up rooted when it comes to growing season, including plants that are supposedly hard to root (such as Melocactus with cephalium).

Though in all honesty I think the reason I have different experiences with many people here on stuff like this is in part because I grow typically quite different plants to most British growers. The kind of heat loving plants I grow are not that common so maybe that's why I've had success doing many things differently compared to common lore spoken by British growers (which often didn't work well for me for what it's worth).

So for example many people here claim that it's fine to spray plants with Provado and stuff for mealie control over winter, but for my plants that insecticide fed into plants who have a low water volume due to winter shrinkage regularly resulted in winter deaths due to the higher concentration of insecticide that inevitably resulted. I barely lose plants over winter anymore since I stopped doing that for example so I strictly avoid insecticides in winter now.

Similarly the whole leaving stuff to dry out never worked well for many of my plants - Opuntia brasiliensis and Pilosocereus leucocephalus are two plants that come to mind that barely even grow unless I keep them almost completely damp for 6 months of the year. Only watering them every few weeks and letting them dry out in between nearly always resulted in next to zero new growth for the year.

[DaveW]

Found this old post on degrafting on CactiGuide.

http://www.cactiguide.com/forum/viewtop ... 4&start=15

Afraid the pictures have disappeared from this part as it was evidently a Japanese link.

http://www.cactiguide.com/forum/viewtop ... 22&t=34104

[SandraS]

I am new here but have recently bought a Hildewinter which is grafted and was wondering what to do with it. A small half cyclinder of Hildewintera stem was grafted onto a sion. The flat surface onto the top of the sion. It has since pruduced a 4 inch sturdy stem from a bud which has flowered. ( I am not sure how to add a picture) I had decided to leave well alone until Spring but what should I do then? Any advice would be much appreciated. Sandra