During late winter to early spring, it produces large, goblet-shaped flowers that are pure white in color. These flowers can reach a width of up to 30cm. Magnolia ‘Sir Harold Hillier’ itself has a broad, conical shape and typically begins to flower around three years after it has been planted. Magnolia ‘Sir Harold Hillier’ is deciduous, not native to New Zealand, and a hybrid between Magnolia campbellii ‘Alba’ and possibly Magnolia denudata. ‘Sir Harold Hillier’ was selected by Nigel Holman before 2000 in Cornwall, England.