Bit of a gardening novice and could do with some advice on a vertical wall garden I'm creating.

We have a town house with a medium sized garden which is on a steep incline (2m drop from house to back of Garden). To make it useable we've raised it to the house level by creating a decked frame which has a combination of decking and artificial grass on a sub structure shed. This has also meant the walls have had to come up on 3 sides. To get some planting we added a bricked planter accross the rear wall and have some large pots placed around. But I wanted to mask the expanse of walls and spotted some grow up wall planters on clearance at Homebase (£3 each) and ended up purchasing and installing 22 of them in 3 sections (pictures attached):

https://whitesgroup.com.au/garden-up...r-details.html

As you can see from the second picture i'm in the process of installing micro irrigation. On the lookout for a decent water timer for scheduled watering if anyone has any recommendations

So having done the technical/DIY bit which i'm comfortable with, I could really do with some advice on planting and drainage. Given the number of pots, the plants won't be cheap and I dont want to kill them if I can avoid it

For Drainage I'm thinking:

1) Drill 4 extra holes in the bottom of the pots.
2) Superglue geotextile (I have some left over from drive way) over the holes to prevent soil leakage.
3) Add around 1-2cm of gravel to the base of the pots to provide a drainage resevoir
4) Another layer of Geotextile to prevent soil getting into the drainage layer
5) Add some Westland water saving gel to the soil to provide reservoir for the plants whilst preventing soil from becoming waterlogged.

Each pot clips into the one below. So whilst they unhook quite easily, they have to be removed top to bottom. Given the number of pots it will get quite annoying doing this 2 or 3 times a year. Therefore for plants ideally we'd like predominantly evergreens.

My wife really likes the idea of herbs/etc. We visited our Garden Centre and she picked out (haven't bought yet):

1) Ajuga Catlins Giant
2) Lithodora
3) Rosmarinus officianalis prostratus
4) Seneco "Angel Wings" - probably not suitable for these pots, but would love something similar
5) Thymus Serpillum
6) Heuchera Carnival Electra
7) Hebe Magic Summer
8) Lavender

Please be gentle if these are bad choices and not suitable for this type of pot/installation We took a pot in with us and and asked what would be viable to plant in them and then shortlisted what we liked. With a mixture of upright plants for the centres and those that will cascade down for the edges. The idea being to mask the actually planters as much as possible (I sprayed them to match the wall as closely as possible to help).

We have a beautiful red mini acer which looks stunning against the blue walls. So any suggestions for something that sort of colour would be very welcome. Unfortunately we couldnt find anything in the garden centre.

If you've got this far thank you for baring with me, I will stop here. Any and all advice greatly appreciated