Grafting Cactus Seedlings
Pereskiopsis is often used as a rootstock for grafting cactus seedlings. It is a commonly used method, but this article is not about that (there’s lots of videos on YouTube) . It’s about an alternative method which I came up with after writing the previous article about grafting cacti.
If you haven’t read it already, follow this link Grafting Cacti Part 2 as it will give some perspective about slab grafts.
In the previous article I proposed that slab grafts offered a better union between the scion and rootstock simply because if exposed more of the vascular ring of the scion which allowed you to position it better on the rootstock and hence get better contact between the two.
This is debatable of course, so I thought why not put it to the test with a tiny cactus seedling.
So here is the candidate. It’s a “Roseii 2 x Peruvianus Sausage” seedling. It’s about 2.5 cm high.
So, step 1 is to prepare your rootstock. For this graft I used a small Psycho0 rooted cutting I’d grown from an areole graft a couple of years previous.
In fact, you’ll also need 2 rootstocks, as this seedling is about to become 2 scions.
Next use a very sharp, thin bladed knife to cut the top off the cactus seedling to use as the scion. Then slice it along it’s length. The idea is slice it right along the length of the vascular ring and in effect turn the seedling into 2 slabs. Similar to the scion on a slab graft.
Be accurate though, as you may only get one chance at this as it will most likely be too small to trim up later.
Also make sure you have your rootstock and ties ready. As it is basically, slice the scion in half, attach it straight to the rootstock and then tie it down.
Here are the grafts. In this instance I wasn’t quite sure what I was going to use to secure the scion. I thought my rubber band method may have applied too much pressure to the small scions and squashed them. In the end I used some stretchy, fabric garden twine I got from Bunnings.
I left the garden twine on for about a week. In the end the scion attached itself just nicely to the rootstock. The photos below were 7 days after the graft.
They then went outside into a small greenhouse and the rootstocks got watered with a Seasol solution.
Then a few weeks later.
Plus on the other one, unexpectedly, the tip started to grow.
As you can see, when the scion got sliced a small part of the tip remained on one of the halves and now it’s regenerated.
So why use this method for grafting cactus seedlings?
It’s probably not a method you’re going to use on a whole batch of seedlings. But if you have a few unique seedlings which are very different or superior to the rest, it could be a good way to accelerate their growth. Seedlings also have quite a small diameter vascular ring. This is a good way of virtually increasing the size of the vascular ring to get much better contact with a larger rootstock. Plus, now you have 2 clones of the same seedling. Bonus!!!!
Some Considerations using this method
Firstly, the garden twine I used only applied a minimal amount of pressure. At first I was skeptical it would be enough pressure to keep complete contact between the scion and rootstock. In hindsight, I probably should have used another tie at 90 degrees and next time I think I will. In this case though I got away using just the one tie. The seedling was quite hydrated though. So maybe this helped.
Also, as I mentioned earlier, make sure the rootstocks and ties are ready before you cut the scion.
You might also notice from the photo of the 2 scions above. The scion on the right only has a sliver of vascular ring. So if you find you don’t slice it correctly and all of the vascular is on just one of the scions, I’d still go ahead and try grafting the scion without. There are still connections between the vascular rings and areoles. So it possibly will still take and hopefully pup. Just like of the scion on an areole graft.
Anyway, I’ll update this again in a few months. It’ll be interesting to see how quickly the scions grow. At the moment they are in a well lit greenhouse which gets a few hours of winter sun per day. Once the weather warms and the sun gets higher in the sky I will need to be careful not to give them too much. But it will probably depend on how big the scions are at the time.
So if you try this in the warmer months I’d keep them completely out of the sun as even the smallest amount of sun could be enough to burn them completely.
Best of luck if you give it a try! I’d love to hear how you go.
UPDATE 10/12/2023
Here are some other seedling grafts I’ve done since.
Here is the whole of the rootstock. The other tip graft is a Super Pedro which was grafted earlier in the year. It’s growing nicely and will possible eventually become a rootstock itself. As the other schick pups get larger, they will also be used as rootstock.
I’m also tempted to just cut the long rootstock with the Pedro and then re-root it. That way the remaining cactus can put more energy into the Terscheckii.
Therefore, considering the subsequent grafts, I think that possibly using the stretchy garden twine might be a better option than the rubber bands for securing the scion. Stockings may also be a good option as well.
Rubber bands are a great option for larger scions but possibly not for seedlings!
UPDATE 28/04/2024
We’re well into autumn now in Melbourne. The weather’s getting cold so it’s probably a good time to do an update on how these seedling grafts have faired.
Pilosocereus Pachycladus. The tiny pup has grown nicely but slowly. As you can see the other half of the seedling hasn’t shown any signs of growth at all.
Probably a victim of the rubber bands providing too much pressure . . . once again!
This Terscheckii and it’s other half are still attached to the rootstock but haven’t grown at all. Once again, likely a victim of too much pressure being applied by the rubber bands.
Terscheckii tip graft. This one is going great and has achieved the most amount of growth. It’s the one grafted to quite a large schickendantzii. The rootstock is quite a large clump, in a large pot with a big rootball.
I think if you are going to graft slow growing scions like a Terscheckii, then use the largest, fasted growing rootstock you have.
Finally the original subject of the experiment!
In Summary
Some points worth noting.
- For a really small seedling, be careful not to apply too much pressure to the scion.
- Make sure the scion and rootstock are well hydrated before grafting. This will assist in achieving a good contact when bought together ie helps them to stick!
- I’d consider placing them somewhere which is dry (low humidity) and cool, with a minimum daily temperature variation while the graft heals. I left the original graft inside during winter and both grafts took really well. I think hot weather (even in the shade) can sometimes dry the rootstock too quickly, causing it to pull away from the scion before contact is fully established.
FOOTNOTE
If you’re going to try this method using small seedlings like the Roseii 2 x, then maybe use some seedlings you’re winning to sacrifice, until you’re confident you can get it to work. You don’t want to risk something special and have it not work out.
Alternatively, if you can wait until they are a little larger, then your chances of success will increase. I suppose my original graft was one I wanted to try, just to see what was possible!
