Port St. Lucie
We had a wonderful speaker on Tuesday, April 9th who shared some wonderful tips for success with your Dendrobiums. I am pleased to present the following:
Tips from Roy’s presentation 4/9/2019
Best growers have several things in common.
The media pH is between 5 to 7.
Media is low in salt deposits.
Pest and disease absent.
Humidity near 70-80%
Avoid extremes of temperature and moisture. Thick leaved Orchids need a 10 – 30 degree differential in night and day temperatures. The stomatas will never open without the differential. Crassulacean Acid Metabolism CAM .
Nutrition is in balance with light, temperature, plant type
Dendrobium simple test for pH
One year in pot
Media: bark, perlite, peat
pH buffered with fine dolomite
without dolomite, pH is below 4.0 in three months
65 AG 65 mesh/inch screen
½ teaspoon per 4” pot
City water with low alkalinity and 40” of rainfall per year
How is your water? It may be the most important nutrient that we do not monitor for its content. Total dissolved minerals, pH, and alkalinity are strange factors to consider. They are critical for the end result
as we try to grow the perfect Orchid.
Best article: What’s in Your Water? By Jack and Cari Peters, Orchids Magazine, May, 2012.
Choices: Peters 20-10-20, Cal-Mag 15-5-15, Peters 10-30-20
Michigan State 13-3-15, Peters 20-20-20
Weakly weekly. What does it mean.
Nitrogen: Urea, ammonia, nitrates
Phosphorus 2% to 40%
Potassium 1% to 20%
Flower Boosting Summary
Roots and environment perfect. pH must be 5 – 6.
humidity 70-80% low salts in media
Give as much light as plants will tolerate with lots of aeration.
Use high calcium fertilizer one month before spike formation.
Use at rate of half teaspoon per gallon per week. With 1/8 teaspoon micro nutrient package.
Extra phosphorus does not help.
See “Without High Phosphorus” by Jan Szyren, Orchids, June, 2003.
Low nitrogen helps. Ammonia and urea will favor vegetative
growth at the expense of flowers. Nitrates ok.
Roy’s Secret Potion
On mature plants. Just before the spikes appear. Apply calcium type fertilizer llike Peter’s Cal Mag Special, at ½ teaspoon per gallon with a micronutrient package like Miller’s Microplex, at 1/8 teaspoon per gallon. Weekly until spikes and flowers appear. Maximum 3 months.
If it does not work. We need to run diagnostics. Something needs to be fixed.