Sorry, what do you mean by training plants? Do you mean something you can train up the wall? Will you be making a bed along the front of the wall? I can't think of any climbing plants that would suit such a low wall but a row of ferns along the base might look nice. Its such an attractive little wall it seems a pity to cover it up! However if you plant some Euonymus fortunii at the base of the wall some of the shoots will grow upwards like a climber. But unless you make a bed whatever you plant apart from ferns will get swamped by grasses you won't be able to mow round it properly. It looks as though there is standing water - is the ground very wet even in this very dry summer?

I think Rosie means trailing plants but I could be totally wrong :)

yes sorry trailing plants to tumble over the wall!!

Very little to be honest Rosie, try vincca… and ivy. Even they will need watering to start with until they are established. Could you not plant things to grow up the wall?

I dont know if this plant would be successful in your conditions but it is unstoppable in my raised beds.It is called Carpobrotus Rossi,aka "Pigface"(see my photos)I got it from a market last year in two 5"pots and it has just taken off.It is so easy to grow.If a piece breaks off I stick it in a pot and and it roots easily.The chap I bought it from said it was the same type that grows down over coastal areas so I suppose harsh conditions are no problem.Google it and see what it says,good luck,kerryvw.

Given that Carpobrotus rossii is a succulent I doubt it would do very well in the extremely dry conditions there would be around the roots of the conifer hedge. Not sure how well it would trail over the wall to be honest either.

Do you removing the lawn on front and creating a border there? The wall that you have added looks very good. It really works well with the hedge.

Moongrow,It does very well in the dry conditions of the raised bed which I never water ,it also has very prolific trailing properties which, if you had experience of instead of assumptions would have known.I try to give HELPFUL advice on subjects that I have had an experience of .You should try it sometime ,instead of giving your negative,"personal disliking ", responses Like Ah,Astro turf...Shingle..if he wants that he should live next to a beach...and many more I bet.People have a perfect right to do whatever they want in their own gardens and the sooner you realise this ,the better,If this response warrants me being taken off the site,so be it,kerryvw.

I agree people do have a perfect right to do what they want Kerry. My comment was simply that my reading up of the plant indicated it might not survive well in dry conditions… You may never water your raised bed but is it full of tree roots meaning the soil will not only be dry as dust but there will be no nutriment in it either. If you'd been part of GoY as long as I have you would discover I have given an awful lot of clear positive advice. Sometimes though what the person is asking is not feasible. Hence the suggestion to create a bed in front of the rather super stone wall and plant things that can go up it.

Kerry i have sent you a PM.

I do agree, getting anything to grow under conifers that size is difficult and I can't think of any trailing plants at all for a north aspect - the vinca might survive but it wouldn't be lush to say the least.

Kerry the plant you suggest grows natuurally on sand dunes in Australia, where it is very sunny. This little strip of ground in addition to being dry is north facing and therefore sunless. I don't suppose you have made your raised beds in deep shade.

That was part of my concern Stera. the deep shade… vinca seems to cope with, just about, anything as do some of the ivies but this is a challenge. I can think of plants that will cope with poor soil and plants that will cope with shade but, not both!

I have cordylines and conifers in both beds one of which is in permanent shade.Both of you have only read of these plants while I actually have them and I know what conditions I am growing them in.Listen,I am not saying that this is the answer to the problem, only that it could be ,which ,if I am not mistaken,is the whole point of this site.steragram,have left a reply in your PMs kerryvw.

Getting back to Rosie's problem... A 12ft high wall of leylandii (sorry - can't bring myself to call something that solid a hedge) will be sucking almost every last gasp out of the ground. It's not clear how much space there is in front of the leylandii as to whether there is any overshadowing from buildings or if there is a good clear space - it may be north facing but doesn't necessarily mean no light.
Little ferns growing in the stone wall would be nice and some of the small native geraniums - I'd take a look at what grows in the walls of any narrow country lanes round and about where you live.
As a 'proof-in-the-pudding' - I planted a 2" pot of viola cornuta alba a few weeks ago in my tiny back yard (surrounded on all sides by terraced houses and high walls). Planted in a sink garden in about 4" of soil, it has already spread to almost a foot and this weekend had about 30 flowers on it. I also have a vinca 'Gertrude Jekyll' growing in very poor soil which is just about holding its own.

Kerry I do not wish to make this a personal slagging off contest but I assure you we have a long conifer hedge in our garden and know exactly the problems it causes. Not sure where the cordylines come in though! I am now going to stop following this question as I these comments do not serve Rosie.