Barrett remained in New Plymouth as the settlement grew, establishing a commercially unsuccessful whaling station and serving as an unofficial harbour master, helping immigrants ashore as ships arrived. He also became a gardener and farmer. He drove the first cattle and sheep to Taranaki from Wellington and introduced a wide variety of new crops and vegetables. He missed the landing of the first settlers, who arrived on the "William Bryan" in March 1841, because he was about 10 km inland, searching for peach trees he had earlier planted.