Failing Mature Euphorbia Trigona-Floppy arms, discolored

Hi,

When I purchased it from a small local, nursery they referred to it as "The Good Luck Plant", without out ANY mention of the risks of the "African Milk" thank goodness my kids are older. I found the name on the pot.

I bought the plant a little over two months ago (Sept 2014) I do not know how long they had it at the nursery. They had it against the building, under the large eves, in an enclosed courtyard, with heavy screen/netting as a roof and watered it weekly.

It was about 5 feet tall, in a 20 inch round pot, bright/dark green stalks covered in leaves, all standing straight up at attention - SUPER LUSH.

I bought it for my great room (indoors). This room has tons of floor to ceiling windows and my plant went in front of a 18ft tall - 5 feet wide north facing window. This is a great room with floor to ceiling windows across the room along entire east and southern walls. Nursery said it would be "fine" in this location.

About a month in, I noticed the ends of the arms were lighter green, nothing notable just... lighter. I didn't know if it was new growth, normal adjustment... or a real problem. I asked two people at a large, local nursery and they said it was "probably fine". Noting that they had all of their Euphorbia Trigona's tied together to stay up and they clearly had spider mites...I thought maybe they were not the best resource...

So I emailed the botanical garden knowing they had volunteers that may be able to assist me. They tried to help me and said, they believe it was not getting enough light and it should be moved outside. So, I moved it outside, close to an outside wall but fairly out in the open. It was getting morning light. It started drooping terribly that day... Maybe the stress of being moved? Although now tons of arms we floppy and arced or just laying on top of itself. The edges looked worse, now turning whitish with brown stain looking spots and a little red mottled in. YIKES! (I still have no idea if it was fine in my great room and I should have just let it settle in).

In a desperate act, I moved it into my outdoor courtyard, 3-wall-enclosure (no roof). Additionally, to provide more "protection" I placed it up next to my front door... Then I decided to cut off the floppy arms (disease/dead/ fine)... whatever it was. I ended up cutting almost every arm, at least 75% of the plant down to 3 feet tall. It is still outside in front of my door, facing north, but getting a lot of filtered light throughout the day and reflection off pavement. I have a large, mature (18-20 year-old) garden in this same area with flowering plants, yucca's, agaves, etc. it was here when I moved in 2 years ago.

I live north of Scottsdale, in the foothills (Tonto Forest Area). We tend to run about 5-8 degrees cooler than Phoenix along with more wind. It has been known to snow here 1-3 times each winter, not a lot of accumulation, but it sticks for a bit and in the summer hit 118 on the really hot days. I believe we are considered 9b zone.

I thought it was stunning & bought it... now I just want to help it live.

I am not sure how to do the following:

1- Do I leave it outside or bring it back inside?
2- If I leave it outside, should I move it somewhere else?
3- If I leave it outside, despite that it is a mature plant (guessing by how big it was and number of "arms") do I cover it with a frost cloth?
4-How often should I water? More or less since it is outside?
5- I think it has spider mites too, I am unsure if I should treat it or just let it calm down?
6- If I treat it for spider mites, if that is what the little tiny white spots are (some webbing too) it arrived with this, whatever it is.
7- Should I plant the cuttings or are they diseased?

If I moved it indoors, it would have to go back to original great room window, as I do not have any other locations available -

Any help and or suggestions would be welcome :) Thank you!

Without a picture it sounds like the plant got sunburned pretty bad, and went south in other ways thereafter. Moving an indoor succulent right out into the sun is a risky maneuver, best to find it a place in bright shade first then maybe a week or two later move it into morning sun. And so on. Unless the wall faced north, the plant almost certainly got a little fried. I have killed a number of plants and had to learn the importance of gradual accommodation the hard way.

These Euphorbias are pretty common and therefore relatively easy given the right conditions. I would not imagine they make great house plants, but I've never tried. I have a couple that I started from stubby little 4" cuttings 2-3 years ago, now they're maybe 4 times that size. They can handle a pretty wide range of light levels, but tend to do better with some protection. About half a day of sun is good here. Probably less in Arizona.

Plants in the ground can handle more exposure, are more drought resistant, and tend to have better biological resistance to pests. Containers that get exposed to the sun tend to turn into casseroles and cook the roots; this is less of an issue in the ground.

Definitely start the cuttings if you think they have potential. As long as you put them in a mix with good drainage (lots of rock) they should be pretty easy to get going. Just be aware that they may skip a season while they are deciding what to do. Start the cuttings in relatively small pots, that way you can water them without worrying too much about rot. Once you see new growth you can pot them up into a larger container as necessary.

Water when dry or almost dry. More sun = more water. Indoor location = less water. Winter (short days) = less water. Cold temps = less water. To give you some idea of the factors in play.