What's eating my alisma plantago-aquatica?

Common water-plantain is primarily threatened by waterfowl that uproot shallow-planted crowns, and by water-lily aphids on emergent flower stalks in summer. Slugs and snails attack emerging leaves at the pond margin. In garden ponds, waterfowl are the most reliably destructive pest.

Crowns dug up or shoots stripped at the waterline, especially in newly planted ponds. Plant in heavy baskets topped with gravel; use wire-mesh protection for the first season until roots anchor firmly.

Dense colonies on flower stems and leaf undersides; sticky honeydew and distorted flowerheads. Hose colonies off emergent stems into the water; do not apply insecticides directly to pond water.

Irregular holes in newly emerging leaves and soft stem bases at the water's edge. Use iron-phosphate slug pellets away from pond edges; hand-remove snails found on foliage.