The history of the gravestone of Sylvia Plath is tumultuous. On 30 April 1963, just over two months after Plath's death, Aurelia Schober Plath, the poet's mother, received a letter from Hilda Farrar, an aunt of Ted Hughes'. Mrs. Plath routinely annotated her letters with thoughts about the correspondent, ideas for replies, and, as well, comments intended solely for her eyes. Her notations were made in something resembling cycles: both upon receipt and as well through re-readings over the years. Many were made, also, as she prepared her daughter's correspondence for publication in Letters Home (1975), and when she surveyed her daughters' papers—and part of her own archive—for sale to the Lilly Library (1977). In the letter cited above, Hilda wrote: "Billie [Ted Hughes' father] and I went to look at Sylvia's grave last week and he tidied it up as best he could. It appears it is unwise to put up a headstone for some months until the ground has had time...
Sylvia Plath Info Blog by Peter K. Steinberg. The blog of A celebration, this is.