Rumex hydrolapathum
water dock
Overview
Rumex hydrolapathum is a tall, robust waterside perennial growing 5-7 feet (1.5-2.1 m) high from a stout rootstock. The large lanceolate basal leaves are 1-3 feet (30-90 cm) long, mid-green, tapering at both ends, and turn red and bronze as the season ends. In summer it sends up branched flowering stems carrying dense whorls of small greenish flowers that ripen to reddish-brown, three-winged fruits. It grows at the margins of rivers, ponds, ditches, canals, and fens, rooted in wet mud or shallow water and tolerating seasonal flooding. The size and reddish autumn color make it a structural plant for large pond edges and bog gardens, though its bulk and free seeding limit it in small spaces. The foliage contains oxalic acid and can cause digestive upset if eaten in quantity by people or animals. It is the main larval food plant of certain wetland moths. Top growth dies down in winter and the plant resprouts from the crown in spring, reaching full size within a few seasons.
Native Range
Rumex hydrolapathum is native to Europe and western Asia, where it grows along the margins of rivers, ponds, canals, ditches, and fens. It favors wet, fertile, muddy ground and shallow standing water at low elevations.Suggested Uses
Grown as a structural marginal plant at the edges of large ponds, lakes, and streams and in bog gardens. It supports wildlife as a larval host plant and a seed source for birds. Its size and vigorous self-seeding make it less suited to small ponds or containers.How to Identify
Appearance
Size & Dimensions
Height5' - 7'
Width/Spread2' - 3'
Reaches mature size in approximately 3 years
Bloom Information
Branched stems carry whorls of small greenish, wind-pollinated flowers from June to August. The flowers ripen to clusters of reddish-brown, three-winged fruits through late summer. The dried seed heads persist into autumn and winter.
Detailed Descriptions
Flower Description
Greenish turning reddish-brownFoliage Description
Mid-green, reddening in autumnGrowing Conditions
Sun Requirements
Requires 6-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight