A single branch died 3 weeks ago. 2 weeks ago another one (I just cut it off then) Now this week the whole plant has died. I have no idea why?
Within a radius of 8 meters a lot of very beautyfull plants (also picture) ! Big and healthy. Help!!!
Can it spread?
Oh no, that looks like you have fusarium.
It's a fungus that often comes in when you overwater or the plant stays in too damp soil.
It can spread, so I would spray bio sulphur or copper soap on the stems and then chop and remove the plant.
Might be some kind of fungal infection of the roots or possibly caterpillars eating your plants stems from the inside, you can check her for that (Eurasian hemp borer "Grapholita delineana")
Good luck!