Critical assessment of Dearle's work underwent a significant change during the final decades of the twentieth century, recognizing Dearle's mature work as having a unique artistic vision of its own. Morris's reputation overshadowed Dearle's work throughout Dearle's career: Dearle exhibited early patterns under Morris's name and Dearle designs continue to be sold as Morris patterns. Dearle always remained close to Morris's esthetic, yet from the 1890s onward Dearle incorporated a distinctive set of Persian and Turkish influences.
Henry Dearle began his career as an assistant in Morris & Co.'s retail showroom in Oxford Street in 1878, and then transferred to the company's glass painting workshop, where he worked mornings and studied design in the afternoons. Morris recognized Dearle's talents as a draftsman, and took him on as his tapestry apprentice. Morris had finished his first solo effort at tapestry in September 1879, and shortly thereafter Morris and Dearle set up a tapestry loom at Queen Square. Dearle executed Morris and Co.'s first figural tapestry from a design by Walter Crane in 1883. Dearle was soon responsible for the training of all tapestry apprentices in the workshop and partnered with Morris on designing details such as fabric patterns and floral backgrounds for tapestries based on figure drawings or cartoons by Burne-Jones (some of them repurposed from stained glass cartoons) and animal figures by Philip Webb.
In the late 1880s, Dearle began designing repeating patterns for wallpapers and textiles, and it is likely that his designs for large-scale embroideries also date from around this time.
From 1890, Dearle was head designer for the firm, handling interior design commissions and supervising the tapestry, weaving, and fabric-printing departments at Merton Abbey He was appointed Art Director of Morris & Co. following Morris's death in 1896. Dearle managed the company's textile works at Merton Abbey until his death in 1932.
Fabric and wallpaper designs attributed to Henry Dearle include Cherwell (registered 1887), Trent (1888), Persian Brocatel (c. 1890), Daffodil (c. 1891), Compton (1896), Tulip (1895-1900), Artichoke (1897), and Persian or New Persian (1905).
Dearle also designed embroidery panels for screens and portieres in the Art Needlework style under the tutelage of May Morris, including Anemone (1895-90), and the well-known Owl and Pigeon (or Partridge) (c. 1895). Examples of the latter two designs worked on "Oak" silk damask grounds by Mrs. Battye are in the Victoria and Albert Museum.
As late as 1981, the catalog of an exhibit of Morris & Co. textiles dismissed Dearle's style as "rarely more than a pastiche of his master's", citing as a source Lewis F. Day's assessment of 1905.. But by 1989, textile historians had begun recognizing Dearle's talents as a designer. Linda Parry, a curator of textiles at the Victoria and Albert Museum, has suggested that the incorporation of Near and Middle Eastern designs in Morris & Co. textiles from the late 1880s may show the influence of Dearle's taste. Parry identifies Dearle's mature artistic voice from the 1890s in designs such as Seaweed wallpaper, Tulip woven fabric and Eden printed cotton , the latter reflecting Dearle's interest in Turkish and Persian textiles in the South Kensington Museum (now the Victoria and Albert)..