Plant Profile: Water Hawthorn

Common Name: Water Hawthorn or Cape Pondweed

Latin Name: Aponogeton distachyus

Hardiness: Hardy to at least zone 5. Probably colder as long as the tubers do not freeze.

Light: Sun to part shade.

Size: Can cover an area 2 to 3 feet across.

Notes: Water Hawthorn is a wonderful addition to the water garden and deserves to be used more often. It grows from a small bulb and the floating leaves are long and narrow. This deep-water marginal is native to South Africa and will grow in water 6 inches to 2 feet deep.

The real value in the water hawthorn is its growth cycle. This plant thrives in cool weather and goes completely dormant in the hot summer months. Water hawthorn will show off its small, white, vanilla scented flowers in late winter or early spring, take a rest during summer, and then pick up where it left off in the fall and bloom until the pond freezes over. It is a great companion for water lilies since they perform best during warm weather.

Water hawthorn is very easy to care for. Plant the bulbs an inch or so deep in heavy clay top soil. Fertilize monthly when in active growth. Once the plant begins to slow down as the weather gets warmer, stop fertilizing until you see new growth in the fall.

Water hawthorn is a prolific seeder and you may find baby plants springing up in your other water plants.

It is a good idea to make sure your pots are well labeled so you don’t accidentally mistake a dormant water hawthorn for a dead plant and throw it out!

Water hawthorn will tolerate slowly moving water.

Winter Care: Winterize water hawthorn the same as you would a hardy water lily. Once the plant is killed by frost, drop the pot to the deepest part of the pond so the tubers do not freeze.

Propagation: Division or seed