Miltoniopsis temp control
 

I have two miltoniopsis, which are a couple years into my growing environment. They have been gradually getting more brown spots on the leaves, though they continue to bloom each year. Research here has made me think that my growing environment is too warm - indeed, Seattle's summers have become more warm more often, and this 1920s building holds heat.

If my diagnosis is believable, is there anything to do beyond finding them a new home or running the AC all the time (which I won't do)? I really like my Henry Jackson "Wild Thing" but in a rented studio etc. my ability to change conditions is limited and that might be the final answer!

Perhaps just using a fan in the hot part of the day for better air movement will be something to try if you haven't already? It would certainly be less expensive than relying on the AC. You don't actually mention how warm it gets in your growing environment, so it's hard to know if it's just temperature alone that may be causing the spotting on the leaves.

Find a recent post "To repot or not store bought Miltoniopsis" as these responses are relevant.

Do you have a basement?

Unlikely in Seattle.

I have 450 square feet on the 3rd floor :biggrin:

What if you tried a pot-in-pot method? Get a larger unglazed terracotta pot, put your plant in the middle (still inside its current pot) and fill the void with damp sphagnum moss. Then plunk the bottom of the terracotta pot into a shallow dish of water, so the pot and moss stay damp.

Hopefully others will chime in, but you may be able to benefit a little from the evaporative cooling around the roots, while keeping your plants potted in whatever medium you choose.

I use frozen small cold packs, (for kids lunches) and put 3 in a cool box, against the sides.Add plant but do not let it touch the cold packs. I have a tall cooler and close the lid through the night. Temp stays around 12 Celcius. Refreeze packs every day. The packs last a long time, cost only a few dollars at Walmart.

I lightly spray my Miltoniopsis leaves with Physan 20, whenever I see spotting. Seems to keep all that away. Of course, my environment is not very humid, so that helps as well.