Apparently many churchyards in England have yew trees growing in them. Some of the trees are much older than the churches, and some have obviously been planted there when, or after, the church was built, sometimes near a door, as in the picture below:
The religious/spiritual/ritual/sacred significance of the yew goes back beyond the advent of Christianity in England. Churches were sometimes built on sites that had pre-Christian sacred/spiritual significance, hence the presence of yews already.
The yew continued to signify a connection to those gone before us to the hereafter, and of death, but also of life everlasting - resurrection in Christian terms. So they were often purposely planted on church grounds.
This particular door with its yews is said to be the possible inspiration for the doors of Moria in Tolkien's The Lord of the Rings. It is found at the rear of a church in a small town in the Cotswolds, where Tolkien is said to have gone wandering and sketching. In Tolkien's version, however, the trees flanking the doors are ancient hollies.
An interesting aside, in the Harry Potter books, Voldemort's wand is made of yew wood (it dispenses death, yet its wielder seeks everlasting life), and Harry's wand is made of Holly - anciently thought to be a ward against evil.