temperature for cattleyas

[pokefan_nat]

Once again, I'm here lol. I am trying to regulate my cattleya's day temperatures. I can't grow them outside and sometimes my mom has the AC on 72 F so I bought a plant heat mat that I can change the temperature. I just installed it and I set it to 95 but they say it takes around 5 hours to set itself. I decided to place the mat behind the orchids to see if it would change the air temperature within the small area. I have them on a shelf under a grow light but the grow light is higher than the plants so it doesn't produce heat on them and at the low setting it's kind of intense (Bloom Plus). It also came with a thermometer on the device, so placed it in between the plants by the leaves to see if it would help me understand the temperature for cattleyas. I hear it's around 75 - 80 F. Plus I have a cool humidifier on by the plants. Not sure if that will mess with the results. If anyone has any experience or I need to place it back under the plants, let me know. It's been about 1 hour.

[Roberta]

Which Cattleyas? 72 deg F should be fine for nearly all Catts... most of them can grow much cooler. So it is important to specify the names (so that the ancestry of the hybrids can be looked up) or species name. Then it is possible to get a much better idea of what the plants actually need.

Just as an example, I grow most of my Catts outside (winter night lows into the low 40's F, winter days into the mid-60's or low 70's F), summer night time lows typically in the mid-to-high 60's F, days into the 90's F) Exceptions - C. lueddemaniana needs to be warmer and so gets the greeenhouse, some others that would need to be warmer are C. dowiana, C. violacea... those I don't grow because I don't have room in the GH. Hybrids, depends on which species are in their background. (I don't grow C. dowiana hybrids for the same reason... not enough GH space) So.. the short answer on what temperature, is "It depends..."

[pokefan_nat]

Thank you so much for your extensive reply. I really appreciate it because I was afraid that my day temperature wasn’t going to be the right heating but the orchids that I own are the Rlc. Dick Smith Paradise
(Rlc. Akatsuka x Rlc. Hawaiian Lightning) , Syn. Blc. Hawaii Island Bride
(Ctt. White Bridal x Rlc. Mahina Yahiro), Rlc. Nakornchaisri Red

[Roberta]

All of these are very complex hybrids. But looking at species percentages, here's my best guess

Rl.c Dick Smith 'Paradise' - on the warm side, minimum night temps around 60 deg. F

Ctt. Hawaiian Island Bride - Very complex mix, but should be fine down to 50-55 deg F at night, maybe even a little lower.

Rlc. Nakornchaisri Red - on the warm side (it's half C. dowiana) - minimum night temps around 60 deg. F.

So.... all will be fine with night lows in the mid to low 60's F, daytime highs no particular limit. In short, don't overthink this... In summer you should be able to easily put them outside if you have the space, winter in the house as you have them set up. In later spring,summer and early fall, if you can provide a space with filtered sun (protect from direct sun at mid-day) they'll benefit from the light, temperature range, humidty, and air movement that Mother Nature provides.

[pokefan_nat]

Thank you so much for researching the parentage. I understand then more now that I have this information. When summer hits I’ll try to find a place in the back where I can keep them or put them in a big bush. I do also have a few trees but idk about the squirrels. If all else fails, I’ll look for a shading device I can place them under. I do appreciate the information. Will I need to water them more often like 2 - 3 times a week if they’re outside in pots ?

[Roberta]

Watering depends on humidity, temperature, and media/pot. Catts in general need to pretty much dry out between waterings. So the "when to water" is an exercise in observation. You'll have to see when they're getting to the "nearly dry" stage to figure your watering frequency. (Same is true indoors... can't really gauge it by the calendar)