Monkshood (Aconitum)

This graceful plant with distinctive, deep-blue hood-shaped flowers (hence the common name) and glossy dissected leaves takes center stage in the late-summer garden. Aconitum prefers cool summer nights and warm days with low humidity, but it's hardy from Zones 3 to 7. Mature plants are 2 to 3 feet tall and nearly as wide. plant monkshood in rich, well-drained soil in full sun or light shade. Set plants 3 to 3 feet apart with root crowns just below the surface. The plants multiply slowly and survive for many years.

Monkshood flowers for about a month in late summer and fall. It doesn't need staking but requires deadheading to renew bloom.

Insider's secret If grown in damp soil, monkshood will rot, so choose a well-drained spot. Don't plant it where children play: It's deadly poisonous if eaten.