Dendrobium Orchids – Hard Cane
One of the main ingredients for growing good Dendrobiums is plenty of air movement. If you can achieve this you are half way there.
Housing
Your orchid house will require 70% shade cloth with a solar weave or fibreglass roof. A gravel floor dampened down 3 times a day in summer will provide good humidity. All my larger plants (90mm pots) are hung up to stop them from falling over also maximising airflow. During June, July and August cover the south and west walls with solar weave to stop the cold southwest and westerly winds. The reason for the roof come to the fore during winter, it stops the cold rain and drizzle from getting on your plants.
Pests and Diseases
I use Supracide and Cabaryl, these are compatible and will control all sucking and chewing insects. Apply end of October/November when new growths are away, and again early March-just before buds start to open. From mid May to the beginning of spring I use 1 gram of Octave plus 2 grams of Mancozeb per litre of water to control Anthraenose = Colletotrichum/Glomerella which causes terrible leaf drop. This was recommended to me by the DPI after submitting affected leaves. I use this brew about 2 or 3 times during this period. Through the flowering season control flower spotting (Botryitis) by keeping the floor dry and clean and spray with a pool algaecide e.g. Guardex. Spray plants and flowers with non staining Rovril every 3 to 4 weeks depending on weather conditions. I do not recommend spraying plants with Guardex.
Watering
One of the main ingredients for growing good Dendrobiums is plenty of air movement. If you can achieve this you are half way there. In winter water early morning, only on clear sunny days every ten to fourteen days. During September to November water once or twice per week and November to mid March 2 to 3 times per week.
Now that you have grown and flowered you prize Dendrobiums you will want to win first prize on the show bench. Try to train flower spikes by facing them to the north. Always display racemes to their best advantage and make sure you separate multi racemes with a styrene wedge. Phalaenanthe Dendrobiums look best in their natural arching growth habit. If staking is required then stake in this manner. A well-displayed plant will always have a far greater chance of winning.
Fertilizer
Use at manufactures recommended strength. September fortnightly with high Nitrogen. October till end of December weekly with high Nitrogen. January till mid February weekly alternating between high Nitrogen and low Nitrogen. This will harden up the canes and help with flower production. Mid February to mid April weekly low Nitrogen. May through to early September every 3 weeks with low Nitrogen.
Pots and Potting Mix
Medium size bark or bark and charcoal and super course perlite may be used. Pot size Plants straight from community pots should be potted into 50mm tubes using a fine mix. They should stay there for 2 years before being repotting into 75mm – 90mm pots. Repot in early spring keeping pot size to a minimum.
These notes have been used at our Cultural and New Grower’s Meetings. They are from various sources and we thank the authors. All articles are supplied in good faith and the Bribie Island Orchid Society and its members will not be held responsible for any loss or damage.