Practical Gardening: Grafting Christmas Cactus to Dragon Fruit Plant

Video Tutorial

Watch the video below to help you better understand the rest of the article.

Christmas Cactus and Other Holiday Cacti

The first time I saw a Christmas Cactus, I couldn't believe cacti would grow and develop flowers that way. In a recent project, I was able to graft the moon cactus to the dragon fruit plant. I was amazed how the dragon fruit plant can be used as a versatile grafting stock for cacti.

Just for reference, here are examples of Holiday Cactus in full bloom (stock photos and not mine):

Note:

For the purposes of discussion in this article, any reference to Christmas Cactus would also mean any Holiday cacti like the Thanksgiving and Easter cacti. The author understands that the Holiday cactus presented in the photos of this article is the Thanksgiving Cactus, also known as Crab Cactus or Lobster-Claw Cactus.

Why Graft the Christmas Cactus to the Dragon Fruit Plant

I could think of some reasons why you'd want to graft the Christmas Cactus or any other Holiday Cactus (like the pictured Thanksgiving Cactus above) to the Dragon Fruit plant.

Robust and Vigorous Growth. Holiday Cacti are not common where I live. I realize that they struggle to survive on their own and it's maybe due to the climate. The Dragon Fruit is known for its robustness and pest-resistant characteristics especially in tropical regions. It is commonly used as grafting stock for Moon Cactus.

The Dragonfruit plant is quite hardy and grows anywhere, at least hereabouts. They're popular for their fruits and they're so common now that they're not hard to find. They're easy to propagate and grow. So, if you're looking for a good stock (or rootstock) for propagating the Christmas Cactus, the Dragon Fruit plant is a good candidate.
Attain a Certain Height. The Christmas Cactus generally droops. It grows by producing a series of stem segments that are flat and connected by nodes. They could be put on display with hanging baskets. By grafting them to a taller stock like the Dragon Fruit, you're able to give the Christmas Cactus a 'trunk' to grow on. You'll showcase the Christmas Cactus by grafting it in 2 or 3 layers on the Dragon Fruit trunk.
Different Blooms in One Plant. This is simply one advantage of grafting in general. Wouldn't it be cool to have different colored blooms in one plant? Imagine 3 layers of holiday cacti on a tall dragonfruit stock? How about white blooms on the top layer, pink blooms on the second and red at the bottom? You could actually combine all holiday cacti (Thanksgiving, Christmas and Easter) in one! Not sure how it'll turn out, but it surely would be interesting.

Preparing the Dragon Fruit Plant as Grafting Stock

For this stage, you will need a healthy and preferably mature Dragonfruit plant. One that has plenty of branches to choose from is good enough.

Select branches that are healthy and robust. The branch need not be long as they will be cut into shorter segments later. Choose branches that are reasonably straight and thick.
With a pair of heavy duty pruning shears or sharp cutter, cut the selected branch as shown below.
Divide the branch into shorter pieces around 6 inches long or more. Be sure to clean all cutting implements like cutters and pruning shears with rubbing alcohol. The longer or higher the Dragonfruit stock, the more Christmas Cactus scions you can graft.
Do note the proper orientation of the Dragonfruit cuttings as to which end is the top and which is the bottom for correct planting. Mark with a pen, if necessary.
Let the Dragonfruit cuttings dry for 2 to 3 days. The more sap there is, the longer it may take to dry.
Prepare the soil mix for the Dragonfruit plant rootstock. The soil mix I used is equal parts of: sand, compost, garden soil and rice hull (ipa). You may use other combinations, but the soil mix must be fast draining and loose.
Plant the Dragon Fruit rootstock 1.5 inches deep into the soil mix that is just damp and not soaking wet. Lightly tamp the soil after planting.
Set the planted Dragonfruit cuttings aside for 1 month for them to root. Put them in the shade but where there is bright light. The cuttings should not get wet nor be disturbed by pets or other animals.

Because of the damp soil, there is no need to water the cuttings at all. However, if the weather becomes too hot and the soil dries out, water deeply. Don't water until the soil has dried again.

Preparing the Christmas Cactus Scion

Find a healthy-looking Christmas Cactus. One that has 2 or more stem segments called cladodes, in a leaf-like branch or phylloclade. In the pot below, there are a few Christmas Cacti.
Select a stem segment that is relatively thick and comes from a growing robust plant. For the scion for grafting, you need at least one of these stem segments.
The stem segment will be cut at the node as shown below. Stem segments are sometimes called internodes.
With a thin razor blade, cut one segment of the Christmas Cactus. Make a clean cut at the node or near the base of the stem segment.
After cutting, you will be left with the succeeding stem segment. This may be the only one left in the plant as shown below. Not to worry, the cut in that lone segment in the pot will heal and the remaining plant will produce new segments (or cladodes).
Shown below is the cladode or stem segment of the Christmas Cactus. This will be used as the scion in grafting. You can clearly see the serrations especially the crab or lobster-claw at the apex of the segment. This is typically the feature of the Thanksgiving Cactus.

Grafting the Christmas Cactus Scion to the Dragon Fruit Stock

For this procedure, you would need the following tools and materials: toothpicks or pins, a rubber band, sharp razor blade and a transparent plastic bag. For toothpicks, choose those that have pointed ends. Set the tools and materials on the work table.
You will also need one of the Dragon Fruit cuttings that you have rooted for a month. Get one that is thick and healthy.

Notice that the top cut of the rooted Dragon Fruit cutting has dried and healed. The Dragon Fruit plant has three vertical ribs as shown below.
With a razor blade, make a cut that is perpendicular to the rib. I use a half razor blade as this is easy (for me) to work with and is extremely sharp.
Proceed to make the cut to about half-inch. Depending on the thickness and hardness of the rib, a sawing and slicing motion as you dig into the Dragon Fruit plant may be needed.
Pull out the razor blade and move to make a second cut below the first. The purpose of the second cut is to cut out a wedge piece from the stock. You can either cut below (as shown) or above the first cut.
Cut to about half-inch deep. The end of the cut should be at the point you terminated the first cut. The purpose of these two cuts is to slice off a triangular wedge.
Carefully pull out the blade. The sliced wedge piece should come out on your razor blade as you pull it out. The slit that was made on the stock will be the grafting point of the Christmas Cactus scion.
Get the Christmas Cactus scion you cut earlier. With the sharp razor blade, thinly slice the skin of the stem segment at the base. Slice off enough material that it will fit into the slit at the grafting point of the stock.
This creates a wedge that will be inserted at the grafting point. Be sure scrape the skin on both sides of the base of the Christmas Cactus scion.
This type of grafting technique is called the Side-Veneer grafting. It allows you to graft the scion with lateral cuts on the stock.
With both hands, insert the base of the stem segment into the slit on the stock. Be careful not to bend the peeled base of the base on the way in. There should be maximum contact between the wounds of the scion and stock.
Ideally, the scion doesn't fall off from its grafting point in the stock and should be in place until the graft is fully formed.
To temporarily secure the scion at the grafting point, use grafting supports. One that you can use is a toothpick. An alternative would be sewing metal pins.

You will only be using one pointed end of the toothpick so you could actually break the toothpick in half and use those two halves.
While holding the scion with one hand, hold the toothpick with the other. Pierce the underside of the scion that is near the inside of the slit at the grafting point. Continue pushing the toothpick until it goes through the stock.
The point of the toothpick should enter the stock just enough for it to hold the scion at the grafting point. Avoid thrusting the entire thickness of the toothpick too deeply into the scion. Doing so may create a bigger puncture that may severely damage or tear the scion.
Here's the side view of the newly grafted scion on the stock. Notice that the slit is slanted downwards toward the center of the stock and is not entirely flat or level. By slanting it downard, the scion when inserted is tilted upward and reduces the probability of sliding or falling out.

Grafting Multiple Christmas Cactus Scions on the Dragonfruit Stock

The advantage of the Side-Veneer Grafting technique is the ability to graft several scions at the same time. You can add a scion just below the one you grafted. Or you can add another scion at a different rib on the stock as shown below.
So add the second scion in the same manner as the first one. Preferably, balance the position of the scion inside the slit so it is almost centered in the grafting point.

Below, you'll see the characteristic and distinguishable 'lobster claw' and serrations on the edges of a Thanksgiving Cactus.
Notice how the point of the toothpick goes through the part of the scion which is outside the shaved part (wedge). Toothpicks are just used here as graft supports to ensure the scion is not disturbed.
There may be instances where the first and second cuts overlap as shown below with the left scion. Don't worry too much about these deep overlapping cuts because eventually they will dry and heal.
Shown below are the two scions added thus far. Notice the second is at a lower level than the first and is on a different rib.

Note that you could add scions from different cactus types: Christmas, Thanksgiving and Easter. You could graft several of these on the stock. You have several possibilities when combining different types and different colors on the same stock. You do need to have a taller Dragon Fruit stock to showcase the layers of grafted Christmas cacti you intend to put in.
The third scion will be grafted on the third rib and at a lower level than the first two scions. Notice the thorns or spines on the Dragon Fruit stock have been removed. You can do that by cutting them out with a pair of pruning shears. It makes grafting so much easier and safer.
The third scion below actually has two stem segments or cladodes. Just skip the first segment and cut the node under the second segment. You may have multiple segments on a scion.
As before, cut cleanly at the node below the second segment of the branch (phylloclades) with the razor blade.
Scrape away the skin with the edge of the base being the thinnest part of the wedge. The use of a very thin razor blade like the one below makes the slicing more precise and even.
Finally, add the toothpick or pin as support. You can see the two-segment scion in the completed grafted plant below.

Storing the Newly-Grafted Christmas Cactus

To start the healing process for the cuts and for the grafts to complete and succeed, you need to store away the newly-grafted plant.

Cover the entire plant with a transparent plastic bag as shown below. Ensure the plastic bag is thin, light, and big enough so it can cover the plant and its pot. The plastic bag traps the moisture in the plant that otherwise would be lost due to transpiration. In a way, the bag functions as a propagation humidity chamber.
After putting the plastic bag over the plant, carefully put a rubber band either from above (as shown) or from below at the pot.
Position the rubber band over the plastic bag so it wraps around it. The rubber band closes the opening of the plastic bag. It also secures the plastic bag to the seedling pot so it doesn't get blown away.
Place the the plant in the shade where it is bright, no direct sunlight, and largely undisturbed. Avoid strong winds, pets or other animals that may likely disturb or even topple the plant. At this point, the plant shouldn't be watered especially if the soil is damp to begin with. Keep the plant here for about a week.

Removing the Graft Supports

After a week, take out the plant. Carefully remove the rubber band and then slowly remove the plastic bag that's covering the plant.
As shown below, the stem segments are still green and look fresh. There is no sign of wilting or drooping. This is a good sign that the plant is thriving. The toothpicks also did a good job of securing the scions in place.
Now is the time to remove the graft supports, like the toothpicks. To remove, gently wiggle the toothpick slightly especially if it is deep into the scion. Then twist it a bit so it can dislodge completely. Then slowly pull it out.
You might notice some discoloration that looks like stain on the tip of the toothpick. This is essentially moisture that the wood absorbed after being embedded for a week.
Below, you'll notice that the cuts have dried and are starting to heal. After removing the graft supports, the scions remain in place.

Even tapping or nudging on the scions won't displace them from the grafting point. There is significant success on the graft.
Now you may start the hardening process on the plant. Take the plant out in a place where it will receive only morning sun. It will be good if it will receive this progressively, by first getting filtered light towards mid-morning.
After a week of progressive morning sun exposure, inspect the plant and you will see all the cuts have dried and healed. The scions show signs of vigorous growth.
Looking closely, you'll notice that callous has formed especially on the deep overlapped cuts on the stock. The callousing is an indicator of complete healing and recovery.
Even the puncture hole where the toothpick went through is now dried, healed and barely recognizable.

Watering and Fertilizer

Before watering, check the soil. It should dry out between waterings. But do water deeply. The fast draining soil will take care of removing excess water the plant doesn't need. Avoid standing water or prolonged dampness which can cause root rot.

In general, the Christmas Cactus (Schlumbergera truncata) doesn’t need fertilizer. You may put in an all-purpose liquid fertilizer, but sparingly.

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Grafting Christmas Cactus to Dragon Fruit Plant