Trellising and Pruning
In order for your dragon fruit plants to reach full production, you must provide them with a support structure. This will allow the branches to hang down, stimulating budding and fruiting while allowing for ease of harvest. This page will cover the basic requirements for dragon fruit trellises, and the two main types: single pole trellises, and fence trellises. For other aspects of growing dragon fruit, such as basic care, propagation, and pollination, see the drop-down menu above.
Basic requirements - Strength and durability
When mature, dragon fruit plants can weight upwards of 200 kilograms, which means trellises must be able to support this sort of weight. Further, dragon fruit typically live for about 30 years, and so the materials used must be durable enough to last this time. If you are using exposed metal, make sure it is galvanised or zinc plated, as this will reduce corrosion. If you are using wood, go for rot-resistant options such as hardwood or pressure treated wood, and think about how you could use other materials such as concrete at the base, where there will be excess moisture.
Basic Requirements - Size
While this won’t affect productivity too much, having the right size trellis will make it easier to prune, harvest and pollinate your dragon fruit plants. I would recommend a maximum trellis height of 6 feet above the ground, as dragon fruit typically grow at least a foot higher than their trellis, making it hard to reach for most people. Further, tall trellises can be more susceptible to wind damage, and can more easily become lopsided due to leverage.
Basic Requirements - Spacing
Similar to size, this is another usability issue. If you have more than one trellis, spacing them too close together will eventually lead to maintenance issues as it will be difficult to move between the trellises when the plants mature. If you are using the single-post method, it is recommended to leave three meters between each post, although this can be reduced if you are planting in rows. Other possibilities include alternating between one high post and one low post, using a fence trellis in between posts, or just having one long fence trellis.
Maintenance (all trellis types)
Once your plant begins to branch out, continue to prune out any shoots in the bottom two-thirds of the trellis, as this will suck energy away from where you will most likely get buds and fruit. When your plant matures, you will also need to start to remove some of the shoots from the top, or otherwise they will become overcrowded. A good rule of thumb is to keep every third shoot, with a maximum of three per branch. Keep the ones with the most room to grow.
Single Pole Trellises – An overview
This is the typical style of dragon fruit trellis seen in dragon fruit farms across Asia, allowing the formation of the beautiful “umbrella canopy” reminiscent of weeping mulberry trees. In order for this to happen, a sturdy pole needs to be constructed with some sort of top support. These poles can fit up to four plants around their diameter which branch out in all directions, allowing for good plant density (more than four plants will create too much competition for nutrients). These branches eventually bend down under their own weight, which creates the canopy. When this happens, tiny cracks start to form in the bending branches, stimulating budding and fruiting.
Single Pole Trellises – How to get the “umbrella canopy”
The most important thing when using this trellis is to train ONE stem from each plant up the pole, tying it at regular intervals to provide extra support. This often stimulates aerial roots which further secure the plant to the pole. If the plant puts out more shoots, remove them right away, as you want all of the plant’s energy into producing a thick, healthy trunk which can support the canopy. When your plants reach the top of the trellis you need to start bending the branches over the top support so they will hang down under their own weight. This is easiest done at dusk when the plant has softened from a day out in the sun. If the branches don’t bend easily or just seem to want to grow upwards, make a 45-degree cut (so water runs off) in line with the top of the trellis. This will induce new shoots near the area of the cut, and hence cause the plant to branch out.
Single Pole Trellises – Making the pole
The central pole is usually made from concrete, wood, or PVC pipe. Concrete is probably the best option as it is by far the strongest and most durable. However, you will most likely need to make a form (which can be reused), increasing the cost and time to construct. Concrete poles are also very heavy making them harder to handle and less suitable if you want to grow dragon fruit in pots and move them around. If you are using wood, make sure it is a hard wood or pressure treated wood as these are more resistant to rotting. I personally don’t like the idea of treated pine when growing food, but I know people who have had success with this. You can also add a concrete base to the wood to limit exposure to water. Another option is PVC pipe, which may not be as strong, but it certainly doesn’t break down too quickly. You can always pour concrete down its centre to increase the strength without having to make a separate form. I currently use 100mm PVC pipe in a variant of the Spicy Exotics trellis design.
Single Pole Trellises – Making the top support
There are endless ways to create an effective top support for a single pole trellis, but many designs will use a variant of the following:
1. Car tyre/bike wheel rim fixed to protruding rebar. This can be achieved by inserting two
pieces of rebar, or any other bar such as threaded bar which can be bolted, one on top of the other, through the pole of
choice, creating an x-shape that will be very sturdy. Then simply fix the circle of choice to the bar either through holes, bolts, or similar, creating a nice circular canopy when mature.
2. Wire mesh fixed to protruding rebar in a similar manner to above. This is what Spicy Exotics use in combination with a PVC pole. They also attach some flexible tubing in a
circle around the top to prevent the plants from rubbing
against the
metal, as it can be sharp and heats up in the sun.
3. Rebar protruding from the top of the pole. This is commonly used in Thailand where branches are bent over each other,
and little other support is used. The metal is used to guide and tie the dragon fruit branches (see how).
4. Wooden top support. This is only really suitable with a wooden pole and is probably not the best method as over-time it will rot. However, it can be a great starting place as it is very easy and quick to construct. Typically
square in shape.
The following are links to some great single pole dragon fruit
trellis designs:
Spicy Exotics' PVC Trellis
Grafting Dragon Fruit's Protected Wooden Trellis
Sackboymahalo's Concrete Tyre Trellis
My Sweet Home Garden's Cinder Block Trellis
Fence Trellises – An overview
Growing dragon fruit over a fence is perhaps the easiest way to effectively grow them. Many farms use this method to grow dragon fruit in neat rows, allowing a decent density (lower than single pole trellises, however). Once mature, you will have branches sprawling over the fence, and this bending will stimulate budding and fruiting. However, because of the sheer weight of these plants, you may need to bang some star pickets in to prevent the fence from falling over.
Fence Trellises – Training Your Plants
Training your plants on a fence trellis will be much the same as the single post method (start with ONE stem only!), however, depending on your fence, it may be more difficult to tie them up. If this is the case, consider banging some stakes in, as dragon fruit plants grow faster when they are supported. This will also limit wind damage, especially in the early days. You can either train them on the same side of the fence as they are growing, as I have done in the picture, or train them over the fence. Both methods will work, but the second is not always possible as in my case.
Fence Trellises - Construction
Of course, if you already have a fence, this will be a much easier task. However, it is important there are no sharp edges where your dragon fruit plants will be growing.
And as I said before, consider adding some extra supports to limit the risk of the fence falling over, as this would be rather damaging to your plants (not to mention the relationship with your neighbours!). But, if you are constructing your
fence trellis from scratch, here are some ideas:
1. Metal posts and wire mesh. This method has proven successful for many growers, such as Self-Sufficient Me. It is commonly used in combination with the single
pole method, where it can be installed between each
pole. It is a good idea to run some plastic tubing over the top of it for the safety of the plants.
2. Star pickets and wire. While this is not the strongest trellis option, you could always combine it with a pre-existing fence as I have done in the picture. If you want it to stand alone, put some extra supports on either side of the
trellis to prevent it from
caving in,
and consider fixing a sturdy pole across the top. If you can, get plastic-coated wire (such as washing line), to weave between the holes. This will give you something to tie the stems to as you train them up the trellis, and to protect the plant
from the wire.
3. Wooden rows. This is the method commonly used by farms and is not my favourite because of the risk of rot. However, if you choose the right wood, it will be rather easy to construct and will last a reasonable amount of time. Once
again, wood
can be a good starting place.