[mdjlucan]

Anyone know what's causing this

[mumofstig]

The pink varieties often get dark leaves - there's nothing wrong.

[mdjlucan]

I meant the stem is it peeling

[RubyR3d]

I've had garden birds peeling off the soft bark to make their nests. You seem to have a lot of wildlife you're concerned about. Most is good for the garden.

[mumofstig]

It may just be slugs

[chrissie B]

mine has that as well plant is healthy ive got 6 at the moment and would like one of those more durable ones  that get a thicker trunk I find these type very frail in the stem .
chrissie b

[mumofstig]

The longer they grow the thicker the trunk - so have patience 

[chrissie B]

will do , ive got one that has not had any flowers at all its in a good place on the shed and its a lovley green but sadly no flowers , all the rest have .
chrissie b