Cattleya jenmanii and light intensity
Both PeteM and I created Slippertalk chains in the last several years about our plants from this cross (‘Canaima’s Lipstick’ HCC x ‘Kathleen’ AM). Here is a picture of the fourth blooming of my plant, followed by information about the light intensity this plant has received.
I use an Apogee MQ500 full spectrum meter to measure the peak photon flux density (PPFD) within the photosynthetically active radiation (PAR) spectrum of light. PPFD is measured as micromoles of photons/m2/sec (won’t mention the units again). Daily light integral (DLI, moles of photons/day) is obtained by multiplying the PPFD by the total number of seconds the plant is illuminated per day.
I have grown indoors under LED lights for the last 12 years. My mature unifoliate Cattleyas are currently under Spider Farmer SF600 fixtures at a height that produces about 350 PPFD at the top of the leaves during summer but I raise the fixtures to reduce the intensity to 250 for my cooler winter period. I also vary the day length for my fixtures from 12.5 in summer to 11.5 during the winter. This variation in PPFD and daylength produces a DLI range from 14 in the summer to 10 in the winter. I haven’t read anyone recommending a higher DLI for Cattleyas. This intensity does not cause leaf burning but red/purple leaf coloration does occur on some plants with darker lavender flowers.
In contrast, my younger and shorter Cattleyas, including this jenmanii, have been under LEDone panels (2’ x 2’) for several years. The panel is set to 29 W output and has three different color correction settings labeled 3,500 K, 4,000K, and 5,000K (I use the 4,000 setting). I don’t measure any variation in PPFD with the different color settings, but there is a difference in flower coloration to my eye. One inch below the lighting surface of the LEDone panel I measure 200 PPFD.
The jenmanii shown in this post spent the last year getting 175 PPFD at the top of the leaves (DLI varying from 7-8 through the year). It has grown and flowered acceptably, and I have had other shorter Cattleyas bloom under the same light intensity. I suspect that many orchids can grow and bloom acceptably outside their optimal ranges for light, temperature, moisture, and nutrition.
Both PeteM and I created Slippertalk chains in the last several years about our plants from this cross (‘Canaima’s Lipstick’ HCC x ‘Kathleen’ AM). Here is a picture of the fourth blooming of my plant, followed by information about the light intensity this plant has received.
I use an Apogee MQ500 full spectrum meter to measure the peak photon flux density (PPFD) within the photosynthetically active radiation (PAR) spectrum of light. PPFD is measured as micromoles of photons/m2/sec (won’t mention the units again). Daily light integral (DLI, moles of photons/day) is obtained by multiplying the PPFD by the total number of seconds the plant is illuminated per day.
I have grown indoors under LED lights for the last 12 years. My mature unifoliate Cattleyas are currently under Spider Farmer SF600 fixtures at a height that produces about 350 PPFD at the top of the leaves during summer but I raise the fixtures to reduce the intensity to 250 for my cooler winter period. I also vary the day length for my fixtures from 12.5 in summer to 11.5 during the winter. This variation in PPFD and daylength produces a DLI range from 14 in the summer to 10 in the winter. I haven’t read anyone recommending a higher DLI for Cattleyas. This intensity does not cause leaf burning but red/purple leaf coloration does occur on some plants with darker lavender flowers.
In contrast, my younger and shorter Cattleyas, including this jenmanii, have been under LEDone panels (2’ x 2’) for several years. The panel is set to 29 W output and has three different color correction settings labeled 3,500 K, 4,000K, and 5,000K (I use the 4,000 setting). I don’t measure any variation in PPFD with the different color settings, but there is a difference in flower coloration to my eye. One inch below the lighting surface of the LEDone panel I measure 200 PPFD.
The jenmanii shown in this post spent the last year getting 175 PPFD at the top of the leaves (DLI varying from 7-8 through the year). It has grown and flowered acceptably, and I have had other shorter Cattleyas bloom under the same light intensity. I suspect that many orchids can grow and bloom acceptably outside their optimal ranges for light, temperature, moisture, and nutrition.
