The death of her father in 1876 was followed by a move back to Surrey, which consolidated her garden design ambition. Her mother built a house on Munstead Heath, near Godalming. Gertrude's success in designing the garden was such that, by 1880, horticultural experts were beating a path to her door, in order to see her work.

Her attitude towards garden design was influenced by Arts and Crafts principles, absorbed from John Ruskin (pictured) and William Morris. A sympathetic relationship between house and surroundings was vital; each individual plant should be studied for culture, habit, foliage and colour to achieve a practical, beautiful and appropriate effect. The garden should reveal unexpected views and pictorial surprises.

In his book The Wild Garden, published in 1870, William Robinson advocated a break from the accepted Victorian garden; he favoured more freedom in planting and a wider choice of plants, to give a picturesque and natural appearance. Gertrude agreed and they became close friends; she collaborated with him on The English Flower Garden, published in 1883 and on the house which he bought in 1884, Gravetye Manor, Sussex.