I just recently got a near blooming sized Disa tripetaloides and it seems to be doing alright. But then again, the temperatures haven't been nearly as hot as it was the past couple summers...yet...
I was also curious to see if anyone's had any experience with summer rainfall Disas like Disa chrysostachya.
I have found them fairly easy, I treat them as bog plants. they stay moist get VERY little fertilizer, we have very good tap water where I am (under 35 ppm TDS) so they just get tap water. I try to keep them cool, but it has gone over 100 a few times this year in the GH already....
I only grow hybrids so not sure about the species...