Nymphaea 'Helvola'

Nymphaea 'Helvola' (syn. N. tetragona 'Helvola') is a dwarf hybrid cultivar that has been a cornerstone of small water gardening for over a century. It produces small but prolific star-shaped flowers in soft lemon-yellow over a long summer season, held just above the water surface on short peduncles. The floating pads are one of its most attractive features — small, rounded, and beautifully marked with olive-green and purplish-brown blotching on a mid-green background.

As one of the smallest water lily cultivars available, 'Helvola' is ideally suited to water features where standard-sized lilies would be overwhelming: half-barrel tub gardens, small formal ponds, patio water bowls, and large open-top aquariums. It is also cold-hardy, surviving mild to moderate European winters when planted at sufficient depth.

Growth is moderate and manageable, rarely exceeding 30–40 cm spread. It performs best in full sun but will flower reasonably well in partial shade — a versatility that adds to its enduring popularity.

Light: Medium-high to full sun; will flower in partial shade but most prolifically in full sun. CO2: Not required. Fertilisation: Small aquatic root tabs in the planting container each spring; repot and refresh substrate annually. Placement: Small ponds, tub gardens, or large open-top aquariums; 15–40 cm water depth ideal. Propagation: Divide rhizome in spring — each piece with a growing tip establishes readily.