Black walnut

Black walnuts demand real patience. Even grafted selections typically take seven to ten years before meaningful nut production, and seed-grown trees can take twelve or more. The nuts have an intensely rich, distinctive flavour quite different from Persian walnuts but are notoriously difficult to crack. Be mindful of the juglone these trees exude from their roots — it inhibits many plants within the drip line, so plan your planting accordingly. Once mature, a single tree can produce huge quantities of nuts for well over a century.