Lilies are grown both from bulbs and as water-based plants. Both terrestrial and aquatic lilies produce brightly coloured, attractive flowers that make a distinctive addition to any garden. However, white spots on the leaves of a lily plant indicate a problem that may be fatal to the plant. Identify the cause of the white spots so that the right treatment can be applied to the plant.
Aquatic Leaf Beetle
Water lilies are susceptible to damage from aquatic leaf beetles, which are pests that are drawn to these plants; the beetles may even be present on nursery-bred plants without apparent damage until later in the growing season. One symptom of aquatic leaf beetle damage is the presence of stippling, or white, discoloured spots and flecks on the surface of the leaves. Spray the water lilies with an insecticide and remove severely damaged plants from the garden.
Curl stripe is caused by a virus, known as lily symptomless virus. Despite the name, this virus does leave visible marks on the leaves of an Easter lily, in the form of white spots or elongated stripes on the leaves of the flower. Over time, the leaves begin to curl. There is no treatment for lily symptomless virus other than removing and destroying infected plants. Stopping the virus from spreading to healthy plants is important for maintaining the health of the garden.
Cucumber Mosaic Virus
Easter lilies are also susceptible to damage from cucumber mosaic virus, a disease that affects numerous plants. Overall stunting of growth, including the flowers themselves, is symptomatic of cucumber mosaic virus, as is the presence of small white flecks or spots on the leaves. As with lily symptomless virus, there is no chemical control for cucumber mosaic virus. Remove and destroy Easter lilies that show signs of infection to protect the health of the remaining lily plants.
Botrytis blight is a fungal disease that affects lilies grown from bulbs. It starts at the lower leaves, causing orange or brownish spots to form at the edges of leaves. As the disease progresses, the spots grow and merge, developing white or grey mould spots, which produce spores that spread the disease further. Remove severely affected leaves from the lily and apply a fungicide to the garden to help control the disease and stop it from infecting healthy plants.