What tall plants to plant in tall troughs

[gardenhelppls]

I have treated myself to some rather nice white terrazzo troughs to create a wall barrier between patio and garden and I want to make them have maximum impact. What can I plant in them which will look wow. I think tall flowers and maybe some smaller vivid purple campanula

Any recommendations? thanks!

How big? Can you get some fruit trees in them?

When planting containers you need a selection of plants not just one, so that one is coming into life when the others are starting to fade.

I like to put tall things, medium things, ground cover and then some trailing plants in. i usually go to the local nursery and see what they have that I like and get that.

They are 35 x 75

Actaea are stunning. Black leaves with white flowers and then amazing seed heads through winter. Also Black Sambuca and Cornus Midwinter fire will give you year round drama.

Tall ornamental grasses and tailing plants such as Bicopa.

How about some canna lilies?