DENDROBIUM GENERA CARE
By Lois Rasmussen
I have specifically focused on Dendrobium in this article. It’s the one genera that is so diverse and has very specific requirements based on the ‘sections’ I outlined that I thought a simple “go-by” would be helpful to all. All genera (all plants in nature) have periods of growth and rest and it’s safe to say that all orchids slow down when cooler temps prevail. Less growth mean less water and fertilizer needs. There are, however, certain genera of orchids have very specific requirements. All plants in the Catasetum, Habenaria, and other deciduous orchids all need an absolutely DRY rest once the leaves fall. I hope this article will help you decipher the idiosyncrasies of the Dendrobium genera.
October 1st usually brings nighttime temperatures in the 60s. This signals the beginning of slow growth and therefore reduced water and fertilizer requirements. Since our weather is squirrelly, use the night temps to guide your watering and fertilizing schedule. Below is my go-by that I use to help me keep straight on my Dendrobium collection. This is ONLY for dens! The color by each section is how I flag my plants. Different color ID sticks for each section. But….I have a LOT of Dendrobium. It’s generally safe to use Thanksgiving as the date to stop water and fertilizer in those sections that require it but using the night temps is ideal. Remember, the sections that require a dry rest in nature get higher light and heavy dew early in morning. You can mimic that with a spritz of water early in the day in an area protected from rain but offering good light.
You must know the section that your Dendrobium falls under. Google the name on the ID stick. You may have to dig a bit deeper on hybrids to find out what the primary species is in that plant and then search for the section. Baker’s book on Dendrobium species is excellent for those of you who want to study this genera but they do not address sections. AOS.org has a great article on sections, too. Most of my info, however, comes from orchidspecies.com.
Good luck, happy growing and remember to use your more knowledgeable JOS members as a resource. All of us are eager to help!
NOBILE/DENDROBIUM – FOLLOW ED CAVIN’S PPW
I’ll include this at the bottom. Feel free to print this.
PHAL- (BLUE). EVERGREEN,
SUMMER: >60 at night, Full sun, moist, heavy fertilizer.
WINTER: Rest (reduced water;no fertilizer) from late November until new growth appears, 55* dry, bright light
SPATULA/ANTELOPE -(PURPLE). EVERGREEN, hardcane,
SUMMER:>60, Heavy water/fertilizer, filtered bright light.
WINTER: reduce water and fertilizer, med-hi light
SUMMER- 60-90*, med light, med water and fertilizer.
WINTER: >50, med light, reduce water, no fertilizer
SUMMER: Warm, heavy water/fertilizer;
WINTER: >50, cool/dry, no fertilizer
SUMMER: never dry when in growth, heavy fertilizer
WINTER: >50-60*, rest with sl. moist until new growth shows, no fertilizer.
SUMMER: Warm, moist, hi fertilizer.
WINTER-NO water, mist only early am, NO fertilizer, cold, dry rest
WINTER: Dry between, >45*, fertilizer all yr.
WINTER: Dry during cool weather, no fertilizer, high light
PLATYCAULON- (PLATYGASTRIUM). WATER AND FERTILIZER ALL YEAR. >60
SUMMER: WET, WARM
WINTER: >60, DRYER BUT NEVER DRIED OUT, FERTILIZER ALL YEAR, HIGH HUMIDITY
SUMMER: FILTERED LIGHT, MOIST, WARM
WINTER: Drier but do not dry completely, no fertilizer, >50
NOBILE/DENDROBIUM. This is a month to month formula to go the very best Nobile section Dendrobium in our area.