Hard Cane Type
by Roy Andrade
Disclaimer: This information is for general information purposes only. Opinions expressed by authors and speakers are theirs alone, and not those of HOS. HOS does not endorse specific plant care products, including but not limited to pesticides.
Sufficient light is important for healthy orchid growth. Try to provide bright light in the range of 50% to 60% sunlight. Pay attention to the color of the orchid leaves. Light to medium green is good light condition. Dark green leaves mean not enough light. Adjust light conditions gradually. Plants take a week or so to get acclimated. Do not place them in direct sunlight or the leaves will burn. I grow my dendrobiums in 50% to 60% shade and some are in full sun. Move plants in the winter months. Summer time is way too hot to survive a sudden move.
Most dendrobium like warm to hot temperatures in the range of 75 to 90° F and night temperatures in the range of 65 to 75° F. You should provide good air circulation to help keep plants from overheating if temperatures approach 90 degrees.
Over watering is the number one killer of most orchids. Do not over water. Watering can vary, depending on the type of media used. They should be watered in the morning and allowed to dry before night. I water every two to three days and water in the morning between 6am and 8am. Always look at the root system; nice white roots with green tips are healthy happy roots.
Dendrobium like humidity in the range of 60% to 80%. They grow just fine on any side of the island.
You should fertilize on a regular basis during the active growing period. Fertilize at 50-100% strength. Use whatever fertilizer you have. Feed weakly weekly. I fertilize my dendrobiums every week, and alternate use of a 13-2-13 and a 15-5-15 product. Every fourth week, I feed with 10-30-20; I also use a hydroponic supplement.
Nutricote is also a good fertilizer to use. It’s small pellet type and should only be added once every 6 months to a year, depending on what type you buy. Be sure to read the labels and follow directions. You can also use a good balanced fertilizer. Equal parts of each component (examples, 10-10-10, 13-13-13, 20-20-20). During the winter months fertilizer should be reduced to every two to three weeks at 1/4 tsp. per gallon. Dolomite is good to add to orchids when transplanted or divided. It gives orchids a source of calcium and it helps to adjust the pH of the media. Helps raise the pH. Most fertilizers are low in pH, around 3.5 to 4.5 when diluted with water. The pH will come up to 6.5. If your media is old and decomposing, the pH will be low or acidic. Always wash your hands after handling any chemicals.
Mixes will vary depending on where you live and how you water. Always try to select or make a mix of media that will not stay soggy. Dendrobium don’t like to have wet feet. A good mix that gives good aeration will give you happy roots. Medium to large bark mixed with perlite or a little peat moss is good. Blue rock is also a good choice if plants are a bit large. The rocks will get hot if the orchid is out in bright sun. I use medium bark #7 mix with expanded clay balls [clay pebbles, or LECA, are hydroponic media]. For large, top-heavy dendrobium, I use blue rock with a little bit of bark on top to prevent the rocks from getting hot. Stick to what works for you in your growing area.
Select a pot that will fit the root system. Dendrobium like to have the pot on the tight side. Good drainage is the key to look for in pot selection. Be sure to pot the orchid firmly in the media. Select a pot that will give room for two years of growth. Clay pots and cement pots are good but heavy. Plastic pots are light and are fairly cheap.
Check plants for signs of pests and treat with the correct product to prevent the spread of insects that will cause damage or kill the orchid. You should follow the mixing instructions on the container. Wear protective clothing and a proper mask. Treat the infected plant or plants and spray the area around them. Check and re-spray 3-5 days after first treatment. Monitor then treat another time 10 days later. Be sure to keep records on when you spray for insects. There are many good products out [for the hobbyist and home gardener] so read labels to be sure it will kill the pest you have.
Other products that I use are neem oil, horticulture oil and insecticidal soaps. Remember to read labels and follow directions. Wash your hands after handling products. Use gloves if possible.
Always practice good record keeping so you remember when and what you did with your orchids. Be sure to place the tag back into the correct plant. Write the date on the pot when you transplant or divide your orchid. The back side of the tag is also a good place for the info. Always keep a good clean work area for transplanting your orchids.
Dendrobium culture sheet courtesy of Roy Andrade, Ewa Orchid Society & HOS. Slightly revised to remove named brands.