Repton's book makes little mention of planting at Uppark, with the driveway plans identifying an area merely as the "flower garden to remain." However, in 1812 he and Sir Harry discussed the idea of a Linnaeus flower clock, an arrangement of plants whose flowers would open and close at particular times of the day from which the time could be roughly established, although difficulty in achieving any precision forced the pair to conclude "therefore we must give it up."
Following a visit to Uppark in 1815, Repton wrote that "in no place have I ever seen such accurate attention to olfactory joy as at Uppark. Every room has its depot of odours for permanent use while every window has its Orange Trees and Tuberoses and admits perfume from the surrounding beds of Mignionette and Heliotrope till the whole is an atmosphere of sweets."
He also remarked how pleased he was that, in contrast to some country estates, Uppark welcomed strangers to enjoy its beautiful surroundings, and that "even the house itself throws open its doors to the inquisitive."
The alterations made during the Repton era are often considered the garden's zenith, leading to the Trust's decision to present Uppark as a product largely of the Regency period.
The twentieth century
Ordnance survey maps reveal how some features were lost over time, such as the truncation of the east half of the circuit path by 1911. Others had been added, for example the seasonal bedding scheme laid out in front of the east pavilion as photographed by Country Life in 1910.