Convallaria majalis - 2015

I love lily of the valley,but just can't get it to establish in my garden.?

That is some clump, Andrew.

Siris - they have been there for nearly 30 years. I have to reduce them as well.

They do some times take a while to establish initially, then they pop up the other side of paths and slabs etc. Have a yellow variegated leaf one, couldn't find the one plant, then discovered 3 amongst the London Pride.

I've tried putting a physical barrier in the soil to stop them spreading too far, but the odd one still keeps popping up on the other side of it.

Some spreading plants, which I like but would take over I put in a bucket sunk into the ground.

I use a similar method with a plastic flower pot sunk in the ground, having cut the bottom off. Mint grows well like this provided it is divided as soon as it has reached the edges of the sunken pot.