Trifolium repens 'Purpurascens Quadrifolium'
my friend's garden is being taken over by Trifolium repens 'Purpurascens Quadrifolium' (sometimes known as the purple 4-leaf version of Irish Shamrock). It seems to have rooted itself fairly deeply. Is there any other way of getting shot of it short of digging deep to remove it and putting down thick black weed suppressant plastic? She does want to be able to re-plant once she has eradicated it.