Posted: 03/10/2016 at 15:02
Why did you not spend a bit of effort and dig it out?? Cut those exposed roots and heave it out or get someone with a stump-grinder to remove it.
As an aside; worms you find in the garden soil are not the correct worms to put in a compost heap. You want brandlings, tiger or compost worms which will find their own way to compost heaps.