Sometimes we come across questions about our water lilies or our water gardens that could use some guidance from the experts. Here are some everyday water gardening questions and solutions.
What is eating my water lilies?
The holes could be from terrestrial snails, aquatic snails, fungus or moths. In the following we will address the moth problem.
Especially in the warmer summer months in Hawai’i, you may find moth larvae eating holes in your lily pads. If this is the case, you could have a China Mark Moth or borer at work if you notice holes in your lilies and bumps in your stems.
What to do if you have China Mark Moth?
You can prune severely until the problem disappears. You may notice ‘jigsaw’ shaped cutouts of leaves being used as a cover or ‘sandwich’ for the larvae. This is how the China Mark Moth got the name ‘Sandwich Man’ or ‘Taco Man’. Squish the larvae and feed them to your fish.
Luckily, China Mark Moth is easy to control in water container gardens when you are aware of what to look for and take to pruning leaves and squishing larvae when they appear (see photo).
If the problem persists: Next steps
If pruning or squishing the larvae does not take care of it, spray BT (bacillus thuringiensis) as a foliar spray at dusk, until the problem is under control, preferably on a dry night (it often rains in the night here in Hawai’i, so just do your best). BT is a natural bacteria that kills the larva but is safe for pets and fish. As with many sprays, it is best applied at the end of the day since the caterpillars and larvae of the China Mark Moth are active at night.
Terrestrial snails?
If you have land snails munching on your leaves, wrap the bottom of your water garden with copper tape, to discourage snail foraging.
Aquatic snails?
If you suspect your water snails are eating your water lily pads, check out this post on snails.
Water Gardening is easier overall than regular gardening and keeping your water lilies happy is worth it! Don’t forget to stop and smell the sweet and crisp fragrance of a water lily bloom.
