By Notacluemick
United Kingdom 
I have a small purple flower taking over my lawn.I have been told it is called SELFHELP and CREEPING JENNY!
It is very deep rooted and I have tried Verdun to remove it but after 3 doses over 6 weeks it is still in the lawn. Can anyone help me with this problem?
Thank you in anticipation,
Mick.
8 Jul, 2013
Self heal is the correct name, Prunella vulgaris, and a right nuisance it is too.
To quote
Organic
The most effective organic approach is to weaken the plant by hoeing it wherever it appears in beds or borders, or to dig it out using a fork or trowel. If it establishes itself in the lawn you will have to lift and replace the affected turf in order to deal with it effectively.
Chemical
In lawns, use a weedkiller such as a 2, 4-D-based herbicide to remove self-heal. Apply in cool, moist, calm conditions when there is least risk of accidentally damaging nearby garden plant
8 Jul, 2013