I would love some help with my garden. I have a very uphill garden with two retaining walls. One of which is connected to an enormous rockery. It is very deep and about 20 metres long. The rockery is really all you see when you look out of the living room window due to the incline of the garden so I want it to look good.
I have removed some very old plants from the 1960s which were overgrown and woody. There are gaps all over and I have spent over £500 on plants in the last few days with the idea of filling them. Sadly now I have placed the pots and planted some of them in, I feel completely defeated!!!! There are still gaps everywhere. I cannot see how I will ever fill this space unless I spend a further £2000 or so on plants! I have thought about extending the landing strip of lawn which is between it and the second retaining wall but of course there will be some cost to this as lots of top soil will need to be added. I am not sure if I am better investing in more plants instead! A real dilemma!
I love alpine plants but of course they tend to be small. I also would like everygreen plants if pos so it doesn't look bare in winter.
I have next to no gardening knowledge but have been trying to get inspiration from watching every gardening programme I can but this is overwhelming in terms of size to fill!
Thank you for reading my first ever post

and any help would be so welcome.
PS I have added pics of the rockery