Rumex longifolius aka Dooryard Dock

Rumex longifolius is a perennial in the dock family, Polygonaceae. Its common names include northern dock and smooth-fruited dock. Rumex domesticus is a synonym for the same plant. It comes from temperate parts of Europe and Asia. Its range spans northern Europe, Russia, China, and Japan. The RHS lists it as native to Britain and Ireland. In the wild, it grows beside rivers and in ditches. It also grows in damp grassland.

This dock reaches about 4 feet [1.2 metres] in height. It flowers in June and July. Each flower has both male and female organs. Wind carries the pollen between flowers. Its damp habitats help explain its need for moist soil. Suggested garden settings include meadows and bog gardens. These settings should still provide drainage around its roots.

It grows in sun or partial shade. It accepts sandy soil, loam, and clay. For best growth, give it deep, fertile soil with humus. A fairly heavy soil that holds moisture suits it well. The soil should drain well rather than stay waterlogged. It tolerates mildly acid, neutral, and mildly alkaline conditions. Sow seed outdoors in its growing site during spring. Spring is also the time to divide established plants.

The leaves and seeds have recorded food uses. Cook the young leaves as they emerge from the ground. They have served as a vegetable and an antiscorbutic food. Ground seeds can go into gruel or bread flour. Plants For A Future gives its edibility one out of five. Its oxalic acid content calls for care with food use. Large servings can interfere with calcium and other nutrient uptake. Cooking lowers the oxalic acid content. People with kidney stones or gout should take extra care. The source also cautions people with arthritis, rheumatism, or hyperacidity.

Plants For A Future also records traditional medicinal uses. These involve the whole plant, with emphasis on the root. Reported uses include astringent, digestive, and tonic preparations. Its medicinal rating is one out of five. These records describe traditional uses, not proof of effective treatment. The source gives it a low rating for other uses. However, its dye note concerns related species, not this dock.