I have two Oleanders on my terrace. Since yesterday I noticed that on both the plants the leaves started going yellow (not the new ones). At first I thought it was part of their life cycle (for example, bamboo), but I am not so sure that's the reason.
Sasha
overwatering or lack of fertilizer, i would say.
I would guess either overwatering, or maybe they're getting too rootbound in those planters. They're not a particularly "hungry" plant in my experience so I think needing fertilizer is a little less likely (although definitely something to investigate if it's not a watering or pot-related issue)
