Water Hawthorn is a quite picky plant with a couple of quirks, it can struggle in hot waters... in a semi shaded position where waters rarely go over 70°f it can grow incredibly strong during the cool months, making blooms about six inches in size
Take care to get Water Hawthorn as a young plant with some intact roots. By growing them in clear bottles, I notice the adult plants make amazing long delicate roots that go round and round the pot... When these are ripped off, losing their roots, the corms never seem to do more than struggle... and fizzle out. Moving corms with a lot of root damage cripples them.
When they find a position they like, they grow robust outside of the warm Summer months, a real treat when the hardy waterlilies are fizzling out.
In the Carolinas, they flower throughout Winter, except when freezes burn off the surface foliage... they do like heavy shade through midday towards mid summer
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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.
