Planting problems

[woolshortage]

I have a strip of bed, approx 70cm wide along the side of my lawn. The (ugly) garden fence runs along the other side. This bed has been beautifully planted at one end (approx. 6m of length) by someone that had a clue with things that flower alternately e.g. forsythia, wigelia, magnolia, japonica kerria, pyrocanthus.

My plan was to continue planting along these lines down to the house end of the garden (an additional 7m). I fancy more of the same or similar - maybe buddleia, tall hydrangea. (And I would love a holly bush as I am abroad and you rarely see holly here and it makes me feel nostalgic!)

Here's the problem. At the house end of the fence, but on the other side of the fence is a huge hornbeam which doesn't belong to us. On our land, the lawn is poor quality near the hornbeam as it takes all the moisture away. I was in the garden centre this week asking what I could plant along the bed that would survive with the monstrous hornbeam in close proximity. I was advised nothing would thrive unless I raised the bed up about a foot, so that I would have a solid layer of good soil on top of what is there already due to the roots that will be underneath.

I am wondering how I could raise this bed at least along part of the 7m length. I was in the garden centre yesterday and saw lovely limestone stones and wondered about building a wall around part of the bed to raise it by about a foot in height. But then saw the price of the lovely stones and worked out this would cost me 100s of Euros to just buy the stones and I can't really justify it. Or I could but these hideous cement monstrosities - kind of hollow half moon things that you can plant things into but I really don't like the look of them.

So thank you if you've read this far! My questions are:

1. how can I achieve this raised bed idea without using wood and without it costing mega bucks and without using unsightly half moon things
   
2. am I overestimating my capabilities thinking I might be able to do this myself??
   
3. any other advice or tips?
   
   Thank you! All advice welcome.

[FunkyBoldRibena]

What about pots on the soil itself? Then you can water and feed as and when you want?

[woolshortage]

I did wonder about that if all else fails but it's a windy corner there and I worry about them toppling over. Also wonder if it restricts what I can plant?