unknown plant

Is this low growing and spreading ? It looks like Self-heal. Prunella vulgaris. It was once thought to be able to heal wounds and regarded as a medicinal herb.

Thanks again Blodyn- yes it is low growing but hasn't spread much. I don't know where it came from, don't remember buying it.

It's a wild plant and probably came via a bird or something from a hedgerow. It can be a nuisance in my garden but I try to keep some because of wildlife etc.

My garden has been designed first and foremost with wildlife in mind so it can stay.