It looks like a nutritional deficiency to me.

Thanks AntMary ...Let hear more from others.

Sey

Note how it appears to be focused along the veins and leaf tips? Plus you say even new growth is showing the problem, right? Then assuming there are no sucking pests on the underside of the leaves that are sucking nutrients out of the leaves along the veins - which is the first thing I would think of - and if there are no sign of spores indicating mildew is the cause of the spots - the second thing I would think of - then that leaves nutritional issues.

Dave

Thanks Dave,

I have not noticed any spores nor pests . This plant has been within a few feet from other one, which are not affected. I wanted to ditch it at some point but since it is not spreading anything (likely a physiological problem ?) I kept it.

On The Nutrition:: My thinking has been that it is nutritional too BUT ...

I have been feeding and watering this plant the same way as with the rest of my potted plants, same potting mix, same fertilizer as all my plants ( containing Ca, Mg..)

Other possibilty is some sort of soil borne disease, that is withing the plant (roots) and it is not spreading. So there is an inability to uptake the nutrients.

Just a guess. Not Sure what it is !!!

Sey

Sey, that looks like a plant that's over fertilized. I've done just that myself and had leaves yellow up and then dry up. The rest of the plant was fine and the symptoms finally stopped after the ferts were reduced to nothing for a good while.

I vote for jbann's suggestion, subject to the likely pest provisos digdirt first suspected. It's hard to control container fertilization enough to be sure all is equal, and some varieties react at lower thresholds, much lower.

Cheers

PC