Help! Is my Nandina Obsession dying? With pictures

[Poorlyplants]

Any advice would be gratefully received, planted in a container last spring and it has been thriving ever since, that is until yesterday morning when I noticed a large leaf fall, it looked as though it had been cut on one side, when I lightly brush the plant loads more leaves just fall off, I have kept in watered, hopefully not too much though, it’s by a wall which does not get much sun but is very sheltered. Looking closely at the leaves they have a strange brown edge. Is my plant dying or can I save it?

My guess is it's too wet! It likes well drained soil.
And you can see at the base of the pot that the decking is getting very damp there, and there's a bit of algae. If there definitely a hole in the pot? Could you raise it up on pot feet?

Maybe stick your hand in and see how wet it is, maybe you need to repot in drier soil and water it less.

I'd of said too wet as well because that does tend to cause yellowing/browning. I tend to put my pots on feet (you can get ones that stick underneath so you can't see them).

Thank you both, yes there are definitely holes in the pot, I used a digital metre to read the wetness of the soil and it appeared to be in the mid range but you could be right that I am over watering as I am always worried they will dry out as the rain does not get to it where it’s positioned, so I will let it dry out a bit and get some feet for the base and I think re planting is a good idea. Just hope I can save it!

Was there a heavy frost?

No particularly heavy frost that I am aware of, they are in a very sheltered spot against the house so relatively protected, but literally one day it looked full of health and the next day a massive leaf fall and it looks very sorry for itself, I have a couple more in containers in the same spot and their leaves have started to drop all of a sudden as well