Continue to use it as you are doing. On clay soil the organic matter is beneficial as it improves the soil structure. The only thing lost is the nutrients which are easily added back. In fact some folk re-use multi-purpose compost even in pots and other containers for several years by simply mixing in fish, blood and bone or other general purpose fertliizers to replace the nutrients taken up by plants. No need to ever throw away spent compost (unless you have nowhere to use it.)
Nora, I can open that link using Edge, IE11 and Firefox all running in Windows 10 64-bit so whatever the issue is it seems a bit obscure (as these things often are!)
Looks like a campanula of some type. Unfortunately there are lots of them so can't be more specific.
I agree with FG - try a fork first. If the area isn't too compacted all you would need to do is dig it over and lay some topsol on top. If it is loose enough to dig with a fork then it should provide good drainage and 15cm of topsoil would be fine for turfing on top of. If it's too hard to dig with a fork then you'll probably need to hire a mini digger (about £50 upwards a day.)
Laura, click the camera icon at the top right of the reply box to upload an image. I've visited the link you gave above and have done that for you:
I think 4 may be a rowan and 5 looks like a variegated weigela.
Last edited: 15 July 2016 14:05:40
Also look up scale insects, especially brown scale. Link to RHS:
If it's those, the white stuff is their eggs.
Last edited: 15 July 2016 13:23:31
On the contrary B3, heuchera grow very well indeed in my clay soil. It also has the advantage that vine weevils don't like clay soil. However, they LOVE potted heuchera and I have to heep an eye on them when growing on in pots before planting out. Once they are in my soil they are safe from vine weevils.
Musk Mallow(Malva moschata.) Lovely plant and I let it grow more or less where it wants.
Last edited: 14 July 2016 17:36:28
It may also produce lots of fast-growing vertical shoots (often known as 'water shoots') as a response to hard pruning. If this happens, remove most of them (pull them off rather than cutting them) but leave the ones which are growing somewhere where you want an new branch to grow and nip out the tip which will promote side shoots (= more flowers in the future.)