Hebe subalpina is a bushy, erect, evergreen shrub, growing to 40 in (1 m) or more high. The glossy green spear-shaped leaves are 0.8–1 in (2–2.6 cm) long. The flowers are white; summer. A hebe that is hardy and free flowering in the UK.
It is commonly found at about 3,300 ft (1,000 m) in subalpine scrub in the high rainfall areas of the mountains of Westland, Fiordland and Canterbury, South Island, New Zealand. The name of this hebe has in the past been misapplied to Hebe rakaiensis.