its flowering.. it cant be all that unhappy ....

yet sometimes.. a near death plant flowers as one last gasp for setting seed ..its last gasp at living thru progeny ...

yours does not look that bad ...

that is a huge plant.. in a small pot... and its a heavy feeder in teh sense of a flowering plant .. not just greenery ...

and you have not repotted nor fertd it in 2 years.. if i read right ...

and failure of media... makes it a water management issue... the media is simply not doing the job it used to .. so its sacrificing leaves ...

i suggest you duplicate this post in the houseplant forum .. and the container forum ... and get some experts on repotting ....help you figure how to do that ...

but i would NOT repot during flowering... unless you just want them to all abort ..

ken

ps: all evergreen plants.. eventually shed the oldest leaves ... and yours looks like it is doing that.. just a bit more than normal ...

pps: dont do oleander in MI ... is this a tree ... if so... growing trees in little pots can be very challenging ... others can address that ...

Embothrium, I just double checked, and it is not sitting in water, although the grow pot had a little moisture on the bottom presumably left over from watering 2-3 days ago, and the soil is still damp. It's been partly cloudy and around 60 degrees the past few days here.

Ken, that's right, it has not been re potted or fertilized in 2 years, which might sound crazy. There aren't any roots showing at the bottom of the pot, so it seemed to me (perhaps erroneously) that it was fine in that size of pot. Fertilizing is another issue, I have read that oleander rarely needs fertilizer, but maybe for one in a pot it's a different story. I've just started learning about how to care for plants, and it seems there is a lot to learn! I will re-post this question in the forums you mentioned.

If I do re-pot, would a bagged cactus mix be suitable? I have 2 big bags of it in my shed from last season left over from other plants. I also have perlite and peat moss.

If bottom half of soil column has been chronically soggy for some time that could explain a lack of roots in that portion. Rhododendrons for instance are so touchy about this you can knock an otherwise happy looking one out of a pot to plant it and have the bottom half of the soil drop away like a loaf, the plant never having had anything to do with it.

Keep in mind too that for a containerized plant like this one, that container is its entire universe. I'd suspect some worn-out potting medium is at least a part of the issue here. In any case, it's time to pot it up one size anyway. But don't make the mistake of going to a much larger pot size. That way lies root rot. All the volume of medium in a container can be thought of as reservoir for water. Larger pot=more water held. for a smallish plant, that can result in the medium always staying a little bit too wet. I'm not sure what you have going here but those are a couple areas to consider.

Stress flowering is the response of a starving woody plant trying to maintain the species by flowering and setting seed.

Commercial growers put liners in 3 gallon pots and so on all the time, without having them rot off.