I recently purchased a Zygopetalum mackayi that was grown outside in an area slightly warmer than it is at my home.

When I purchased the zygo it had two healthy spikes. No, after nearly two weeks one of the spikes has completely died and dried (totally brown and brittle). The rest of the plant looks healthy (roots outside the pot are plump and white, leaves blemish free) and the second spike appears to be progressing toward bloom albeit very slowly.

Question: Why did one spike die in such dramatic fashion while one chugs along well?

I suspected temperature, but a quick check of a very complete culture sheet for Z. mackayi shows that in its natural habitat it is exposed to similar (if not lower) temperatures.

Thanks,

Mateo