How big are the pots? How big are the buddleias? Although buddleias can be found growing out of chimney pots on empty buildings, they do have a need for a deep root run. They won't be happy if their roots are going round and round in a pot with nowhere else to go. Can you take them out of their posts and have a look to see if their roots are squashed?
Check the roots for vine weevil grubs - white body, brown head. There is another buddleias thread with a similar problem - check it out.
Cut back on the watering, they like to be dry.
They grow so quickly, they outgrow pot and food. Some I grew from cuttings taken last autumn have already filled a 2L pot and looking for more. Starvation would be my guess
hi, hope you dont mind me butting in on this post, my dwarf buddlies, are in pots, i planted them last year, they where lovely, but this year the flowers are tiny, and dont look very happy, any ideas anyone, thanks
starvation, even the dwarfs are fast growers
hi nutcutlet, what do you mean by starvation? thanks verdun, i will make a note of the above, i just wanted something in my large pots to encourage beas and butterflies
lynne, i meant that stage when the roots ha ve filed the pot and the remaining compost can't retain enough water for the plant to take up any plant food provided
thanks for all your advice, verdun, your agastache sounds lovely, but i have got nowhere to overwinter, and my planters are heavy stone. thanks again everyone