Aquatic Plant Diseases
Plant diseases are caused by various infections and as most grow in water it is difficult to treat them without polluting the pond. It is better to remove the plant and treat it out of the pond. If this is not possible, destroy the diseased plant and replace it with a new one. Most diseases are caused through damage to the plant under the water or through a soil-borne infection; make sure that soils are sterilized before planting.
Bog plants are susceptible to rot when the water level rises too high in the soil; although they need a lot of moisture, once the air is removed there is a danger of root rot.
Fungal attacks should be treated with a fungicide suitable for pond surrounds, and the maker s instructions should be followed. It is often better to paint the plant with the treatment than to use a spray, to lower any risk of the fungicide drifting into the pond. Any diseased leaves should be removed and burnt to lessen the risk of disease spreading to neighbouring growth, and dead leaves should be removed in autumn.