Description of Nymphaea 'Arethusa'

Nymphaea 'Arethusa' is a hardy water lily often listed as a medium-sized plant with relatively small pads and flowers compared with the big pond cultivars. It grows from a rhizome and forms a neat patch of floating leaves, then flowers through summer once the water warms. The cultivar name Arethusa is the key name used in pond plant catalogues. Reliable, detailed measurements from independent sources are limited, so it is best to focus on its use as a tidy, medium lily rather than chasing a single fixed number.

Appearance

Suppliers commonly describe Arethusa as a medium lily with pads around 12–15 cm across and flowers around 10 cm across. The flowers are usually presented as a decorative, star to cup-shaped bloom that sits close to the surface in calm water. Leaf colour is typically green, with younger growth sometimes showing darker tones before it settles. Because both leaves and flowers are smaller, the plant often looks balanced in a container pond, where large cultivars can feel oversized and heavy.

Care Guide

Grow Arethusa in full sun in still water. Plant it in a wide basket with loam based compost and a gravel cap. Start the pot on a shallow shelf so the first pads reach the surface quickly, then lower it in stages. For a medium lily with smaller foliage, aim for a medium depth once it is established, adjusting so pads sit flat on the surface and buds can rise without effort. Feeding matters even for small-flowered lilies, so push aquatic fertiliser tablets into the compost through summer. Remove old pads and spent flowers to reduce debris. Over winter, keep the rhizome below the ice line and leave it in place until spring growth restarts.

Suitability for Garden Ponds

Arethusa suits small ponds, tubs, and patio water gardens where you want a proper water lily without a huge leaf raft. The pads still shade the water and provide cover for wildlife, but you are less likely to lose all your open water to foliage. It also works on a shelf in a larger pond as a smaller companion lily, provided you keep enough space between plants so each has room to flower. A wide basket helps Nymphaea 'Arethusa' spread evenly and stops the rhizome circling in a tight pot. If you want to repot Nymphaea 'Arethusa', do it in late spring when new shoots are moving and the water is warming. In ponds with fish, a firm gravel cap keeps compost in place around Nymphaea 'Arethusa' and helps the plant settle.