This grower is sure of this plant identification.
Goat's beard spiraea
Aruncus dioicus (Goat's beard spiraea). This is a clump-forming perennial species. It will produce large fern-like leaves that are easy to grow. The flowers are small white and will bloom in the summer.
Under shrubs, border, mixed bed. Summer interest.
Hardy Perennial plants - divisions, cuttings, seeds etc. Prefer robust, easy to care for perennials which can cope with heavier soil or damp conditions.