4-6m high screening any ideas ?

Hi I have a lengthy retaining wall which at some points reaches 6m high. I am looking to disguise this with planting climbers initially and some shrubs and grasses or bamboo? Its an exposed coastal site , usually no frost but sometimes a salt wind , as plants have previously been burnt by salty sea winds. I first thought about pathenessisus? (sorry about the spelling) but these sadly are deciduous. Something self clinging would be good. The ground is very poor, manly clay mixed with slithers of rock. also looking for a ground cover to stablise the soil above. any ideas please. Does anyone know how high photinia , red robin grows in these parts please?

 

Hallo Graham,
to Gardeners Corner. Shame your garden is a bit exposed, there's a great rose named after you but it might not perform well. Can you take a picture of your garden to help with recommendations? Others will be along with helpful ideas a bit later on,
Jenny namaste

 

Welcome to GC, Graham

 

Graham - Jenny mentioned there was a rose of your name there is also a honeysuckle with the same name 'Graham Thomas periclymenum' (fast growing) and honeysuckles are good for planting in coastal regions. I would suggest whatever you plant I would think of attaching some wooden supports to the walls (with you being in a coastal area).

 

Ivy,Virginia Creeper,will support themselves ,mix in some honeysuckle and clematis they need support but will cling to the others and get some cover from them, you could get some nice colours going there.

 

I would look at rambler roses such as Kiftsgate and Rambling Rector. They can easily clothe a frame of that height but I wouldn't fancy having to prune them, they are mighty, vicious beasts ! I also don't know how they stand up to an exposed site though I think they'd be fine once they got going. Also, they are deciduous.
At David Austen roses near Wolverhampton they used to have these rose types on huge frames surrounding the car park if you want to see them in action.

I don't think I've ever seen photinia higher than 2m. It would be good to look round the neighbourhood and see how well it does in similar situations, I don't know if the delicate new red growth would stand up to a salt wind.

You could also see if Clematis montana would grow in your situation.