How to Grow a Dragon Bone Plant? Causes of Yellow Leaves and Solutions
The scientific name of the dragon bone plant (dragon fruit cactus) is Hylocereus undatus, also known as night-blooming cereus, sword flower, seven-star sword flower, and so on. It is a plant with extremely strong vitality. Many people grow it at home, which not only adds a lot of vitality to the home, but also purifies harmful gases such as formaldehyde, benzene, radon, and ammonia. So what are the growing methods for the dragon bone plant? Why do the leaves turn yellow?
I. Why do the leaves of the dragon bone plant turn yellow?
1. Normal causes
The leaves of the dragon bone plant can turn yellow due to a variety of factors. First, the dragon bone plant will show yellowing leaves when it sheds its leaves. Usually, during the leaf-shedding period of the dragon bone plant, yellowing leaves at this time is a relatively normal phenomenon, and we only need to remove the yellowed leaves.
2. Improper watering
The second phenomenon may be caused by watering the dragon bone plant too much. If watered too much, water will accumulate at the roots of the dragon bone plant, affecting the root system's nutrient absorption and causing the roots to rot, which then leads to yellow leaves. Once this happens, you need to stop watering immediately. The dragon bone plant enters dormancy in winter, when it does not need too much water; watering once every one or two months is fine. In spring, a thorough watering once every half month is enough. In summer, evaporation is relatively high, so watering once a day in the morning and evening is needed, which will prevent yellow leaves from appearing.
3. Unreasonable lighting
The third cause may be a lighting problem. The intensity of light affects the leaf color of the dragon bone plant. In summer, the sunlight is relatively strong, so we usually need to shade it to avoid damage to the leaves from strong light exposure. In winter, the sunlight is relatively weak, so appropriate light exposure is needed at this time to promote better leaf growth of the dragon bone plant; generally, placing it by a window or under a balcony to grow is enough.
4. Improper fertilizing
The fourth cause may be applying too much fertilizer when caring for the dragon bone plant. The fertilizer needs of the dragon bone plant can be met with a small amount; generally, during its vigorous growth period, once a month is enough for it to grow healthily and robustly.
5. Pests and diseases
The last cause is that the leaves of the dragon bone plant may have been attacked by pests and diseases, producing this phenomenon. We can use antibacterial agents for irrigation, which can effectively prevent and control pest and disease infestation.
II. What are the growing methods for the dragon bone plant?
1. Propagation
The dragon bone plant is mostly propagated by cuttings. During the growing season, cut off plump or older stem segments, air-dry them in the shade for 2 to 3 days, then insert them into a sand bed or soil; they will take root in about 1 month. When the roots are 3 to 4 cm long, they can be transplanted into small pots or planted directly in the open ground. This can be done from spring to autumn, but spring and summer are most suitable. Choose thick, plump stem sections 20-30 cm long, cut them off, and place them in a cool, dry place for several days. After drying, insert them into the substrate. Then keep the substrate moist; they will take root after 20-40 days, with an extremely high survival rate. Cuttings should not be taken when the temperature is below 15°C; with high temperature and humidity, the cut surface is prone to rotting, while at low temperatures it is not easy for them to take root.
2. Planting
The dragon bone plant can be planted in the ground in areas with an annual average temperature above 20°C, with a row spacing of 2.5 m x 3 m. A post should be set up where it is planted, and 3-4 seedlings can be planted beside each post. In other areas, it can be grown in pots; the pot should be large, preferably with a diameter of 25-35 cm, with 1-2 seedlings per pot. The dragon bone plant likes fertile, loose, well-drained acidic sandy loam. For potting soil, a culture soil made by mixing 1 part leaf mold and 1 part coarse sand with a small amount of decomposed chicken manure or cow manure can be used.
3. Light
The dragon bone plant likes light and avoids exposure to scorching sun, so shading should be provided from May to September. When grown for flowers and fruit, it should not be kept in shade; insufficient light will cause the plant to grow leggy and affect flowering and fruiting, but strong sunlight around midday should be shaded. From October to the following April, it should be given sufficient sunlight.
4. Temperature
The dragon bone plant likes warmth, and the most suitable temperature for growth is 20-30°C. It is not cold-tolerant; below 1°C, the dragon bone plant will suffer cold damage and turn yellow. Below 5°C, the stem segments are prone to rotting, and the temperature should be maintained above 12°C for overwintering in winter. The dragon bone plant is heat-tolerant and can bloom normally under high summer temperatures.
5. Watering
The dragon bone plant is drought-tolerant and afraid of waterlogging. During the growing period, the potting soil should be kept moist, but not waterlogged, otherwise root rot is easily caused. If root rot is found, immediately take the plant out of the pot, and use a sharp knife to cut off the rotten parts until reaching healthy tissue. Place the dragon bone plant in a cool, dry place for several days, and replant after the wound has dried. In winter, watering should be restricted; the potting soil only needs to be slightly moist.
6. Fertilizing
Before the dragon bone plant grows, sufficient base fertilizer should be applied, and during the growing period, fertilizer should be applied once every half month. Fertilizing in the early growth stage should mainly be nitrogen, while fertilizing at flowering and fruiting should mainly be phosphorus and potassium. For potted plants grown for fruit, it is best to use organic fertilizer, as this can improve the quality of the fruit. In winter, stop fertilizing.
7. Repotting
The dragon bone plant should be repotted once every 1-2 years, and the old roots should be shortened when repotting. If the roots have tumor-like growths of varying sizes with a rough surface, it indicates that they have been harmed by nematodes, and the affected parts should be cut off. After cutting the roots of the dragon bone plant, place it in a cool place, and only plant and water it after the wound has dried. The growing medium should be sterilized.
8. Pruning
When the dragon bone plant is grown for fruit, the plant should be shaped and pruned; generally, 3 branches are kept per plant. If there are 2 plants in one pot, then 5 branches should be kept, and excess branches should be cut off. During the peak flowering and fruiting period, excess flower buds should be thinned, with only 1-2 retained on each branch; the flower thinning time should be controlled within 8 days after bud emergence. After the production season of the dragon bone plant ends, branches hanging down to the ground, overly dense branches, and old fruiting branches should be cut off to facilitate branch renewal and ventilation and light penetration.
9. Pest and disease control
The dragon bone plant is harmed by pests and diseases such as stem rot, gray mold, rot disease, nematode disease, and scale insects. When the plant is frozen or suffers other external injuries, it is prone to rot disease, causing the stem to rot.