Orange ball buddleja (Buddleja globosa) not thriving

I took a cutting of an orange ball buddleja about two years ago. It didn't do much until I planted it up into a largish container (25L maybe?) in peat free compost this spring. Since then it's grown a lot, from probably about 20cm to 120cm but over the last few months many of the leaves have yellowed and grow seems to have stopped. It's had the odd bit of plant food and has been watered in dry spells.
Is this just the plant slowing down a bit for the winter or should I water more, feed more, doing something else?
Thanks!

 

Hi Andy,
If it was me I wouldn't feed it anymore, you have to remember that Buddleias grow in strange ( ? ) places such as brick walls where they receive hardly any nourishment. Looking at the new growth I would say it's ok as it looks healthy.
I would just leave it now till the spring and let it wind down naturally for the winter.

 

Thanks guys. Unfortunately I haven't anywhere else to put it so I've top dressed the pot with fresh compost and I'll see how it goes next year. Hopefully it won't die before I move to somewhere where I can put it in the ground!

 

If it's outgrown the pot it would benefit from root pruning, then potting into fresh compost and preferably in a bigger pot.