Kaffir Lime TreeA Kaffir lime tree is a unique and exotic addition to any garden or outdoor space in the UK. These evergreen trees are relatively easy to grow and require full sun exposure and well drained soil with a pH between 5. 5 and 6. 5. They are also sensitive to frost and require protection in colder climates. Kaffir lime trees are native to Southeast Asia and are often used in Thai and Southeast Asian cuisine. They are prized for their fragrant leaves, which