Neither should need support if they are growing well. The foxglove might benefit from a thin cane for each flower stem if it is one of the large headed hybrids and you get some blustery weather. Buddleja should never need support.

Thanks for your positive imput

Happy Gardening

Stephen,Cheshire.UK

buddelia in a pot ... ???

my recollection is that they can have a rather massive root structure ... but google images fails on showing you ...

ken

https://www.google.com/search?q=Buddleia+roots&biw=945&bih=745&source=lnms&tbm=isch&sa=X&ved=0ahUKEwirn8P6iZbNAhVJb1IKHemDA5kQ_AUIBigB&dpr=0.9

Ken, anything can be grown in a container!! Especially if in a mild winter area like much of the UK. It is just a matter of knowing how to tend to to long term container plantings, like trees and shrubs. And since Stephen grows a number of containerized Japanese maples, I think he has a pretty good grasp of the processes involved :-))