Question
QUESTION: Dear Mr. King,

I have had two Phalaenopsis(?) orchids living on a south-facing windowsill for nearly two years. During the winter I typically leave the window completely uncovered and allow full light, but in the summer I pull the blinds and keep them partially open. The plants have both seemed quite happy, have flowered several times and one has developed a flowere stalk that has very prettily split into three separate stems. Everything was great until yesterday evening when I came home from a short trip. Apparently my husband thought we needed a little fresh air in our appartment as the weather has been really hot and we don't have airconditioning. It seems he opened the window and expsosed my poor plants to full direct sunlight and temperatures well exceeding 90 degrees for at least two days... All without any extra watering!

Needless to say my plants look traumatized and I am afraid one cannot be saved. All the top leaves on one, and about 30 % on the other, have turned a sickening whitish yellow with little white dots covering the sick portions (the spots were not there last night). The leaves are also mushy and appear rotted underneath.

Obviously I've pulled the blinds again and have moved the orchids away from the window, and given them a good watering, but what else can I do? Should I cut off the mushy leaves? Your advice would be very appreciated! Thanks!

ANSWER: Jennifer, you didn't mention how long it has been since you repotted these plants.  An annual repotting following each flowering is best.  If you haven't repotted, it may be that what you can't see is worse than what you can.  While there's little doubt that the light and heat damaged some of the leaves, these will naturally be shed by the plant.  However, it sounds as if you still have some unaffected leaves that are in good condition.  I recommend that you get some fir-bark based orchid potting mix and soak it while you unpot your plants.  Rinse off your plant roots and remove any that are mushy or stringy.  Healthy roots are firm and turn green when wet.  You may remove  the unsightly leaves if you wish.  Then repot into a clean pot with the fresh wet orchid potting mix and let drain overnight.  With whatever healthy roots and leaves remain, the plant should recover nicely following repotting and, within a month or two, should start producing new roots and leaves in time for the annual flowering next year.

---------- FOLLOW-UP ----------

QUESTION: Thanks so much for your fast reply! I last repotted both plants about 8 or 9 months ago. I am using a pine-bark medium (though I'm not sure whether it is specifically fir bark). The plants are still flowering (since about early March) but the more damaged of the two appears to be nearing the end of its flowering cycle (there is one bloom left, a late-comer and has only been open for about 2 weeks). The not-so-damaged plant has lots of healthy-looking flowers on a branched stem. Given their damage, would it be wise to re-pot immediately to be sure nothing else is going on with the roots, or better to wait until the last of the flowers have dropped? Prior to the damage caused by the plants sitting in harsh sunlight over the past couple of days, I had not seen any indications of root problems on the visible portions (leaves were bright green and there has always been healthy new leaf-growth without any discoloration, wrinkling, pitting, etc. between flowerings), so I doubt there were major problems with rotting/dried out roots before. Could the roots could have been damaged by the excess heat? Thanks so much for your help! It is encouraging to hear that the little guys will probably make it!

Answer
Jennifer, thanks for the additional information. Since you repotted in the past 9 months, I would wait until the flowering has finished and repot at that time.  From your description, it is likely that the roots are okay, but you can check that out after flowering.