Growing Dendrobium Orchids in New Zealand
Dendrobium orchids are common in shops and easy to spot. Many are spray types (often from Dendrobium phalaenopsis hybrids). They grow on trees in nature, so they like air around the roots and a free-draining potting mix.
Light for Dendrobium Orchids
Dendrobium orchids need bright light for good growth and flowers. A bright east or west window suits many New Zealand homes. A lightly shaded north window can work too, but direct hot sun can burn leaves. The plant should sit upright and not need much staking, leaves should be medium green not dark green.
Temperature for Dendrobium Orchids
A clear day and night change helps flowering. Aim for nights around 16–18°C and days around 27–32°C. Short warm spells up to about 35–38°C can be okay if humidity and airflow are higher. Try to avoid nights below 10°C, cold can cause leaf drop.
Water for Dendrobium Orchids
During active growth (usually spring to early autumn in New Zealand, about September to April) keep the potting mix evenly moist. When the new cane finishes growing, watering should change. Let the mix dry more between watering, then water again. The mix should not stay wet for days.
Humidity for Dendrobium Orchids
Dendrobium orchids do best at about 50–60% humidity. In a home, a pebble tray with water under the pot helps (the pot should not sit in water). Good airflow matters, still damp air can cause problems.
Fertiliser for Dendrobium Orchids
Feed once a week all year using either Superthrive Grow 7-9-5 or Superthrive Orchid-Pro 7-8-6. Use 1 mL to 1.5 mL per litre of water. In winter, the feed may be less often than weekly, it depends on how long the potting mix takes to dry out.
Potting for Dendrobium Orchids
Repot about every two to three years, before the mix breaks down. Use a pot that is a bit small for the plant, Dendrobium orchids often grow better that way. Pack the mix firm enough to hold the canes, but keep air gaps and drainage.
In New Zealand, Kiwi Orchid Bark and Bio Leaf Premium Orchid Potting Mix can be purchased from Bio Leaf. See Bio Leaf Premium Orchid Potting Mix and Kiwi Orchid Bark.
Insect Control
Common pests on a Dendrobium orchid are scale, mealybug, aphids, and spider mite. Check under leaves and along canes. Wipe pests off early, and isolate the plant if pests shows up. Treat again after 7–10 days to catch new hatch.
Disease Control
Most disease starts when the mix stays wet and air is low. Keep airflow moving and avoid water sitting in the crown or leaf joints overnight. If a cane or leaf turns soft or black, cut it off with clean tools and keep the plant drier for a while.
Learn More About Dendrobium Orchids
If they would like to learn more about growing orchids, think about coming to the next NZOS meeting. Meetings are a good place to see well-grown Dendrobium orchids, ask questions, and learn simple growing habits that work in New Zealand.
Return to the Orchid Culture Page