Thalia dealbata

Thalia dealbata is a large aquatic or semi-aquatic perennial that is more or less evergreen and surprises with its appearance and its spikes of purple flowers that appear in summer.  It is a remarkable pond plant, whose silhouette brings a very exotic vertical note and a lot of lushness to the garden. It can reach impressive proportions in fertile soil, and under favourable climates, as its hardiness is sometimes lacking.

Thalia dealbata is a rhizomatous perennial plant of the family Marantaceae, sometimes called Maranta arundinacea or Clinogyne dichotoma. It is a plant native to the southern United States, where it grows in marshes, swamps, or warm and sunny wetlands. This amazing plant spreads thanks to large underground rhizomes. Ultimately, this tall perennial reaching 2 m (7ft) or more is capable of forming beautiful, erect and wide clumps of at least 1 m (3ft). The flowering period is summer, occurring from June-July to September. Tall floral spikes emerge from the clump, composed of long leafy vertical stems, ending in clusters of waxy flowers with shades ranging from white to pink, purple, and blue. The flowers, without peduncles, are directly inserted onto the stem, surrounded by bracts covered in white powder. These highly nectar-rich and honey-producing flowers are followed by the formation of large round seeds, purplish and beautifully speckled. In spring, each shoot produces a long vertical stem, with a few large, thick, ovate leaves, measuring 20 to 60 cm (8 to 24in) in length and 8 to 20 cm (3 to 8in) in width. Their colour is bluish-green, sometimes tinged with pink. Thalia dealbata is evergreen in its country of origin, but frost destroys its leaves in our climates, making it deciduous. The plant reappears in spring, forming its first leaves around May.

This Thalia is an excellent plant for wet or submerged areas, which will easily establish in a large ornamental pond, directly in the mud or in a submerged basket under at least 50 cm (20in) of water. Only strong frosts can overcome this amazing perennial. It possesses a unique exotic charm that deserves to be grown.  Thanks to its spreading habit, it can be used as groundcover, even in fresh rock gardens, ensuring it is given enough space. This perennial requires full sun to fully thrive. It can also be grown in a large container on the patio, with its feet in water, and stored indoors away from the cold in winter.