Hebe chathamica is a low-growing, rambling, evergreen, bushy shrub. The light green, thick, broad, spear-shaped leaves are 0.8–1.2 in (2–3 cm) long, and tend to lie in one plane. The flowers open lilac, then fade to white; summer. A hardy hebe in the UK.
Found on coastal cliffs exposed to salt spray, also in crevices, on ledges, and on salt marshes where it can form dense mats, in the Chatham Islands, 500 miles (800 km) east of New Zealand. Hebe chathamica is somewhat similar to Hebe barkeri and Hebe dieffenbachii, also from the Chatham Islands.