Ground elder is a fecker Stig, when I moved in here 5 years back, this garden was overgrown to feck and choc full of ground elder. I simply used Roundup where I could BUT you can't spray it around plants you want to keep or it'll do the lot in. the old boy down the road said simply pour the Roundup in a tin can and using a soft inch brush, paint the leaves...! I thought feck that it'll take ages but it never, it was fast enough as your only doing it round plants you want to keep. Works a treat! Keep the tin and brush out the way and use it when ness!
Cracking garden by the way, love that loo