It is a semiaquatic plant that prefers to grow in about 40 cm (16 in) of water in a variety of wetland habitats.

[6] A cultivar (or perhaps a traditional variety) called 'Grandiflorus', the large-flowered greater spearwort, has 6 cm flowers and is favored by gardeners.

[7] Greater spearwort is a stoloniferous perennial plant with stems up to about 120 cm long, which can start horizonal in mud but then become erect and hollow as they rise out of the water.

The aerial stems are sometime branched and often slightly hairy, with short, eglandular, appressed hairs.

[12] Greater spearwort occurs in a wide variety of wetland habitats, including marshes, ditches, ponds, canals, reservoirs, gravel pits and quarries.