Chamaecyparis lawsoniana 'Blom' is a narrowly upright, columnar selection of Lawson cypress with dense branching, and plates of dark, powder-blue foliage. Structure-wise, plants resemble blue flames in the garden. After 10 years of growth, a mature specimen will measure 6 to 10 feet (2 - 3 m) tall and 20 - 24 inches (50 - 60 cm) wide, an annual growth rate of 8 to 12 inches (20 - 30 cm).
This cultivar originated as a branch sport found in the late 1920's, on a specimen of C. lawsoniana 'Alumii',by A. Blom Nursery, Boskoop, The Netherlands.