Something is wrong with my Euphorbia tirucalli.

Hello,

This is my first post here and I'm hoping someone could shed some light regarding my Euphorbia tirucalli. I bought this plant at a local Garden centre during Summer and it looked very healthy to begin with.

However as the weather has been gradually getting colder I noticed thread like webs stringing in between the stems, perhaps three or four. So my first thought was spider mites, I used diluted Neem oil and sprayed it all over the plant. Now after a couple of weeks it is starting to develop black spots after researching I thought it could be photo-toxicity because of it being in direct sunlight and the Neem oil coating the plant.

I've moved the plant out of my living room away from my other plants just in case it is fungus. So now it is situated in my office.

Any advice to care for the plant is much appreciated.

 

Not much you can do after the fact. I had a similar experience with my Hatiora salicornioides which had been sprayed with insecticidal soap and exposed to sunlight shortly afterward. The growth shriveled somewhat (without any black spots), likely from phytotoxicity, but eventually recovered. There are signs of new growth in the photos so the plant will likely recover given time.

Plant phytotoxicity in the greenhouse