Jade Vine - discoloured rusty leaves - please help

len-juz-99 · August 2020

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Image: https://us.v-cdn.net/6030279/uploads/editor/34/hryqcf8xwg8t.png

Jade Vine - discoloured rusty leaves

Hi, would anyone know, why does my one year old plant of Jade Vine / Strongylodon macrobotrys have discoloured rusty leaves. It has been growing happily inside and since about two months it is outside (green house with filtered light) and was doing very well, till recently when it started to shed some of its old leaves, first creating brown-rust like spots on them. It has lots of new shoots so seems to be regrowing well.
Would anyone know, what is my plant missing?
Thank you.

PS: please ignore that very yellow plant behind my jade vine plant in the picture - it is our tomato plant - done for this year - outside of my greenhouse