Sackville-West and Nicolson found Sissinghurst in April 1930, after Dorothy Wellesley, their near neighbour and a former lover of Sackville-West's, saw the estate for sale.
They had become increasingly concerned about encroaching development near their property Long Barn, near Sevenoaks, Kent.
Their offer on Sissinghurst was accepted on 6 May and the castle and the farm around it were bought for £12,375, using only Sackville-West's money rather than Nicolson's.
The property was 450 acres (1.8 km²) in total.
The house had no electricity, running water, or drains, and the garden was in disarray.
Anne Scott-James notes their "planting inheritance" as "a grove of nut-trees, some apple trees, a quince [and] a tangle of old roses".
The physical assets on the site were "four buildings of beautiful mellow brick, part of a moat [and] various fine walls".
Clearing the ground took almost three years, but by 1939 the garden was largely complete, with the exception of the White Garden.
Nicolson was responsible for the design and layout, while Sackville-West, at the head of her team of gardeners, undertook the planting.
Simon Jenkins, the architectural writer, describes Nicolson's design as "post-Picturesque, a garden not as an imitation of nature but as imitation of a house", and suggests his thinking was much influenced by Lawrence Johnston's garden at Hidcote.
Sackville-West's approach was plant-centred, within the constraints of her husband's plan, "profusion, even extravagance and exuberance, within confines of the utmost linear severity".

The buildings scattered around the site were converted to become an unconventional home.
Part of the long brick gatehouse range from Sir John Baker's construction of c.1533 became the library, or Big Room; the tower gatehouse dating from Richard Baker's rebuilding in 1560–1570 became Sackville-West's sitting room, study, and sanctuary.
The Priest's House was home to their sons Ben and Nigel, and held the family dining room, while the South Cottage housed their bedrooms and Nicolson's writing room.

The garden was first opened to the paying public for two days in mid-1938.
 Thereafter, the opening hours were gradually increased.
Despite her love of privacy, Sackville-West came to enjoy greatly her encounters with the visitors, known as "shillingses" on account of the entrance fees they deposited in a bowl at the gate.
She described her relationship with them in a 1939 article in the New Statesman: "between them and myself a particular form of courtesy survives, a gardener's courtesy".
Nicolson was less welcoming.
Sackville-West's Observer articles raised awareness of the garden; Scott-James records photographic articles in Gardening Illustrated, Vogue, and Picture Post, and notes consequently that "increasingly paying visitors poured into Sissinghurst, coming in thousands in the course of a summer".
Sackville-West and Nicolson found Sissinghurst in April 1930, after Dorothy Wellesley, their near neighbour and a former lover of Sackville-West's, saw the estate for sale. They had become increasingly concerned about encroaching development near their property Long Barn, near Sevenoaks, Kent. Their offer on Sissinghurst was accepted on 6 May and the castle and the farm around it were bought for £12,375, using only Sackville-West's money rather than Nicolson's. The property was 450 acres (1.8 km²) in total. The house had no electricity, running water, or drains, and the garden was in disarray. Anne Scott-James notes their "planting inheritance" as "a grove of nut-trees, some apple trees, a quince [and] a tangle of old roses". The physical assets on the site were "four buildings of beautiful mellow brick, part of a moat [and] various fine walls". Clearing the ground took almost three years, but by 1939 the garden was largely complete, with the exception of the White Garden. Nicolson was responsible for the design and layout, while Sackville-West, at the head of her team of gardeners, undertook the planting. Simon Jenkins, the architectural writer, describes Nicolson's design as "post-Picturesque, a garden not as an imitation of nature but as imitation of a house", and suggests his thinking was much influenced by Lawrence Johnston's garden at Hidcote. Sackville-West's approach was plant-centred, within the constraints of her husband's plan, "profusion, even extravagance and exuberance, within confines of the utmost linear severity".
The buildings scattered around the site were converted to become an unconventional home. Part of the long brick gatehouse range from Sir John Baker's construction of c.1533 became the library, or Big Room; the tower gatehouse dating from Richard Baker's rebuilding in 1560–1570 became Sackville-West's sitting room, study, and sanctuary. The Priest's House was home to their sons Ben and Nigel, and held the family dining room, while the South Cottage housed their bedrooms and Nicolson's writing room.
The garden was first opened to the paying public for two days in mid-1938.  Thereafter, the opening hours were gradually increased. Despite her love of privacy, Sackville-West came to enjoy greatly her encounters with the visitors, known as "shillingses" on account of the entrance fees they deposited in a bowl at the gate. She described her relationship with them in a 1939 article in the New Statesman: "between them and myself a particular form of courtesy survives, a gardener's courtesy". Nicolson was less welcoming. Sackville-West's Observer articles raised awareness of the garden; Scott-James records photographic articles in Gardening Illustrated, Vogue, and Picture Post, and notes consequently that "increasingly paying visitors poured into Sissinghurst, coming in thousands in the course of a summer".
Sissinghurst Castle Garden