Like most grasses, it grows best in acid soils, ideally pH values of between 3.5 and 5, however, it can continue to live under more extreme conditions, sometimes to as low as 2.

Molinia caerulea is a perennial herbaceous bunchgrass (tussock-forming), growing up to 120 cm (47 in) tall (taller when sheltered by gorse and heather), with many closely packed stems.

The leaves are coarse, green, taper to a point, long, flat and sometimes slightly hairy on top.

Purple moor grass and rush pastures is a United Kingdom Biodiversity Action Plan habitat, on account of its rarity.

[7] Numerous cultivars have been selected, of which the following have gained the Royal Horticultural Society's Award of Garden Merit:[8]