I would like to raise the level of soil in a section of my garden by about 1 m (roughly 3 feet). I have a problem though, the bed is already surrounded by a wall but there are existing plants which I'd like to keep if possible. I know its simple enough to move the herbaceous plants like my Zantedeschia's and I will be removing almost all of the existing shrubs, but there are 3 established woody vines (a Zimbabwe creeper, Iceberg rose and Distictis 'Mrs Rivers')which are way too large to move. Is it possible to cover their stems with a meter of soil from the current soil level without killing them or would you recommend against it?

Thanks in advance for any ideas!