Repot it with a different, dryer, potting mix.

kimmq is kimmsr

doubt if you can kill this weed plant ... as in ... grows like a weed ...

just let it dry out ...

it is a deciduous plant ... so it should be losing its leaves .... though it would be nice to know where you are to verify that ...

that said ... dont get all wound up if it does ... its seasonal .. rather than related to this water issue ...

this thing can get as big as a house ... its not going to be happy in a pot forever .... i would think you would be better off planting it .. rather than repotting it.. for the long run ... and if its still holding its leaves .. i would think this is still a good time to plant.. but.. where are you ...

ken

too big for pot

https://www.google.com/search?q=cotinus+coggygria+royal+purple&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiwrrOqqOfQAhWHxVQKHZ-tBF0Q_AUICCgB&biw=908&bih=744&dpr=0.9

I live in Berlin, Germany, and believe me, I wish I had a garden to plant it. But a balcony is all I have.

I was planning to put it in a bigger pot sooner or later, before the end of winter. I know it's going to lose its leaves anyway, but since the other plants in the surroundings are still showing off their amazing flame-like bushes, I didn't want mine to go bald before time comes.

but my point was .... if i wasnt clear ... that losing its leaves should not be correlated to the water issue .... necessarily .. im not sure thats any clearer.. lol ..

also.. you cant compare a potted plant .. to non potted plants in the area .. since the roots can get a lot more chilled in a pot.. faster ... than in-ground plants.. as mother earth cools a lot slower than a pot ...

i just wouldnt worry about the water issue.. let it dry.. and dont put it back in the tray ... trees and shrubs prefer a sip of water.. and near drying before watering again [which of course is complicated by it being in a pot] .... so there should be no need for a water retaining tray ... other than to avoid staining the balcony .. in which case.. turn the tray over as a pedestal... rather than a water retention pond ....

ken

Cotinus can be easily coppiced to be kept to a smaller size and is often included in container plantings for that reason. But I would pot up into a larger size container and I would pay close attention to the soil mix you use, focusing on a very fast draining bark based mix similar to the 5-1-1 discussed in the forums extensively. Cotinus can be prone to root rots that develop are liable to develop rapidly in water-logged soils.