Lily of the Valley taking over

Hello. We planted a few Lily of the Valley a few years ago in our the border in our front garden and now they have pretty much filled the whole border.
They are so beautiful but I think now there are too many.

What can we do to stop the reproduction or to maybe dig some up and move them to the back? Is that done? if so how and when?
Thank you

 

Forgot to mention. Another problem with the L o t V is that there are long blades of grass growing between them. It's such a pain trying to pull them out.
How does one keep that under control? Is there something that you can use to kill the grass but not the bulbs?
That's another reason I'd like to know if it's possible to dig out the L of t V bulbs so that we can rotavate the earth, get rid of the grass then replant the bulbs.
Adivce very needed
Ta

 

Hi Dingbat, welcome to GC,

Too many Lily of the Valleys-a nice problem to have. Just dig up what you don't want trying to keep the bulk of it together as you pull it out.


The blades of grass can only be hand weeded-herbicides tend not to be too specific on what they kill and will just kill off plant material-I don't use herbicides myself ( fortunately I don't have any of the nightmare weeds) but perhaps Verdone might work-I would wait until you get confirmation of one of us who do use chemicals.