Wednesday, July 7, 2010
How to: Propagate Dragonfruit by cuttings
The dragonfruit (aka Pitaya) comes from a variety of species, the most common being the Hylocereus undatus (red pitaya). These cacti are considered to be epiphytic meaning that they can survive on the nutrients and moisture in the air yet they usually still have roots anchoring them to soil. Of all the tropical plants that I am currently growing, the Pitaya is by far the most tolerant to excessive temperatures and brief periods of drought making this a great candidate for desert greenhouse growers like myself. Due to the dragonfruit's long and often unpredictable germination periods propagation by cutting is a no brainer.
Before you start: It is best to do this in warm/moist summer months as this speeds the propagation. Also, don't cut off too much from the parent plant as this will put stress on the plant that may jeopardize its health.
1: Start with a long segment of cactus that can easily be cut into 3-5 sections. Be sure that it is at least a foot long. Try to look for segments that are relatively new but not still growing. I just use scissors to cut the segments into sections that are 3-6 inches long.
2: (optional) Apply a fungicide to the cut ends of each section and place them somewhere relatively dry. This helps deter infections and mold. Note that this step doesn't have to be done but helps with the odds of survival.
3: The next step is to "cure" the cuttings. This allows the cut parts of the cactus to dry out and seal the wound. This is most important in preventing disease and mold from killing the cuttings. I know from experience that cuttings can survive without being cured but it is still a good idea. Cure time should be anywhere from 1-5 days (just wait until the cut ends heal over and turn a little white).
4: Place each cut section in a light soil mix. I suggest mixing some vermiculite and perlite with an average potting soil. Be weary of orientation, each section should be placed in the same direction it was on the plant (don't place them upside down). Each section needs to be planted about 1-2 inches into the soil.
5: Water daily unless the soil is still moist, allow for it to dry out a little. The first thing you might see are roots growing out of the section, this is a good sign of success. These aerial roots will gather nutrients and water from the air, as well as anchor the plant to the soil.
If the propagation was successful a new shoot will emerge. This usually takes between a week to a few months depending on the time of year. Use fertilizer sparingly until they are a year old. Also remember to shield these plants from freezing temperatures.
Within a year the dragonfruit should have numerous shoots coming from the original cutting. These can be heavy and they often go astray so using a trellis or a stake is a good idea to keep the plant upright. In as early as two years you can expect beautiful flowers and delicious dragonfruits. In favorable conditions, a dragonfruit plant grown from a cutting will flower and bear fruit within a couple of years. These night blooming flowers can be elusive to spot during full bloom, but if successfully pollinated the flower will wilt and fall off leaving a developing fruit on the vine. The fruit will become ripe in about a month after pollination.