Paeonia tenuifolia aka Fern Leaf Peony

Paeonia tenuifolia is a perennial known as fernleaf peony. It belongs to the peony family, Paeoniaceae. Its native range runs from Serbia to southwest Siberia and the Caucasus. It grows in temperate regions and is not native to Britain. Soft stems form a low mound or clump each year. The plant loses its leaves and dies back for winter.

Plants often reach 1–2 feet (0.3–0.61 metres) tall. Missouri Botanical Garden lists a spread of 1.5 feet (0.46 metres). RHS gives broader height and spread ranges, reaching 3.3 feet (1 metre). Green leaves divide into very fine, narrow segments. These give the mound a light, fern-like look. The foliage can stay attractive through summer and early fall. Long-lived clumps can remain in place for many years. They do not need routine division.

Single, deep red flowers rise above the fine leaves. Yellow stamens fill the centre of each bloom. Missouri Botanical Garden reports flowers about three inches across. Chicago Botanic Garden gives a much larger figure, eight inches. Flowers appear in late spring and early summer. Missouri records May bloom, while Chicago lists May to June. Each plant flowers for about seven to ten days. The blooms attract butterflies and provide a strong colour contrast with the leaves.

Grow this peony in full sun or partial shade. It needs rich, fertile soil that drains well. Keep the soil moist rather than soggy. RHS lists sand, loam, clay and chalk as suitable soils. It accepts acid, neutral and alkaline conditions. A sheltered site suits it. RHS rates its hardiness H6. Missouri lists USDA zones 4–8; Chicago lists 3–7. Use it in borders, beds, groups or as a specimen. Its low form also suits edging and short herbaceous hedges.

Remove faded flowers, then cut back dying foliage. Divide plants in autumn or early spring when needed. Deer and rabbits tend to leave this plant alone. Pests include leaf and bud eelworms and swift moth larvae. Diseases include viruses, honey fungus, leaf blotch and several wilts. Blights can also occur. Shade, planting depth, frost or recent disturbance may prevent bloom. Ants on buds cause no harm. RHS warns that it can irritate dogs’ and cats’ skin.