'Tenzan' is a very small and extremely dense flat-topped cushion, wider than tall, with short, prickly, robust and tight dark-green foliage that turns bronze-red in winter. 'Tenzan' is prone to burning in the hot sun so provide light shade . Typical rate of growth in most areas is less than 1/2 inch a year, resulting in a tiny bun, 6 inches wide and somewhat shorter after 10 years in the garden.