Help to root a crest.

Hello all,

I recently acquired a Parodia Scopa crest grafted to a hylocereus. Unfortunately the stock was afflicted by some unknown rot and I had to bust it off. This was a few weeks ago and the crest is now very well calloused over. The issue is it has grown into a 'U' shape and any attempt to graft it onto another stock would involve surgery well beyond my current skill set. I would like to put it on its own roots but I have never dealt with a plant grown in this shape.

How do I get it to put down roots?
Do I need to place it on a soil 'mound' so the old graft union point is touching the soil?
Or will it throw roots from any point in contact with the soil?
Is it even possible to get a crest from this species to root after de-grafting?

Any help would be greatly appreciated.

Usually roots will only grow from the vascular bundle of the callous where the plant is cut although sometimes they will grow from the vascular bundle through the body of the plant if you bury it. The main problem is that it takes longer. But also the callous from a graft union that has been snapped off can be quite thick and physically prevent the roots getting through.
As for the best course of action, it depends somewhat how big the plant is. If it is large enough to withstand more drying maybe cut off some of the bits that have grown around to below the graft union and then wait for it to throw roots. Put it somewhere shady out of the wind allow a few days for the cuts to dry and then stand it upright, gravity seems to tell the plant where to throw roots. You can further prevent drying out while the plant is a cutting by wrapping it in glad wrap and leave just the cut surface exposed, or wrap the whole thing once the cut has dried for a week or so. If you are wrapping it be sure it won't sweat. Could be a prob that far north,air holes are an option too. I leave wrapped cuttings in a cool shady place near a window inside my house and they don't mind at all. Sometimes wrapping prevents the cutting stressing too much and makes all the difference to how well it re-established.
If the cutting is small it would be best to just pot it up, and hope for the best. Use some finer growing media around 2mm diameter in a mound under the area you expect roots from, coarser mix will block the way of roots trying to find there way down, then fill around the plant with coarse top dressing gravel around 5-7mm to stabilise it but prevent the plant body contacting damp soil and rotting.
I have successfully grown roots on and established N. scopa pups less than an inch wide so it is do-able.
Good luck!

Thanks crypto. I know its probably not necessary but will a bit of rooting powder help it along? It has been dried out now for a few weeks and is still firm and healthy so it can probably take a few more weeks without sustenance. Should I water it after planting or should I leave the soil relatively dry until I see signs of roots??

I have had the same issue, the crest completely squashed the hylocereus stock.

Managed to remove it from the rotten stock, i cut it in half, dusted with root powder, dried for a week or 2.

They started to root up but i had kept it too wet, they both went moldy and rotten.

I think in your case it would be hard to get the scion grafted point close to the soil/gravel to root up apart from laying it on its side, i think whatever you do make sure it doesn't get to wet.
Try not to water until roots are growing, possibly a very light water.

SneakyCuttlefish wrote:

Hello all,

I recently acquired a Parodia Scopa crest grafted to a hylocereus.
[..]
How do I get it to put down roots?

I hope you have more success than I.  I have now had one for two summers without roots!  Tried everything from shade to sun and nothing works.  I'm tempted to bin it.

Should you get it to root, I am told they are very rot prone (why they come grafted).  It was suggested to use a soil with a minimum of organic material. Good luck.

I had this Gymnocalycium Mihanovichii grafted on hylocereus stock.

Yes the stock went rotten, i ripped it off what was left of the stock, left it for about 3 weeks to dry with root powder, approx 2-3 months later i have roots!!

I think crests are a bit more difficult to root up.

I also have also had my Rebutia Heliosa Crest stock got rotten as well, i think i found it at a good time, i managed to cut and graft 4 parts onto Myrtillocactus, they seem to have taken and am awaiting new growth.

I have never had any success with rebutia crests. They always, without fail, rot straight off the stock every wet season. Come to think of it I have never had much success with rebutia's in general. I'm guessing they are not a very disease resistant species and considering the tropics are full of humidity related diseases, the two probably don't go together very well.

As for the scopa crest I gently peeled off the callous to expose the crispy dry but green skin underneath, applied some root powder and planted it on top of a very sandy soil mix with lots of gypsum, lime, and just a touch of potash. Fingers crossed I get a strike.