Bulba and I don't feed any of our clematis and wouldn't consider feeding C montana. How are you growing it and is it kept well watered? C montana is a group 1 clematis and should be pruned after flowering. That said ours is a total thug and often gets chopped two or three times in the year and still looks good.

Is it in a pot?

Lol Snoopdog! We have a VERY large potting shed the montana smothers the whole of one side of, including the windows, and clambers up onto and over the roof, forcing its way inside and waving at us when we are potting things up. The wind earlier in the winter pulled it right off the top half of the wiring so out I went with the shears and chopped it back. We'll see what happens in a couple of months time but there was no other solution.

I saw one in Scotland like that years ago, completely covered the side of a house, fantastic !

My next door neighbour has one,and it's taken over ..one year he and his late wife had a big argument about it,as she cut it almost to the bottom after flowering..and he went ballistic..Lol...but the following year ,it was beautiful again..but he hasn't done anything with it since..just a huge tangled mess,and the flowers are in abundance..on the other side of his fence !

I wish mine would grow like that. This will be its 3rd year & it has struggled to get to the top of the fence. However it doesn't get much light,tho' it will if it would only get up there. Daren't cut it back or it will never succeed. Also the new shoots keep getting eaten every time it starts to grow.Vine weevil? I have to spray it as soon as growth restarts.