Helping Pond Frogs Survive Winter in a Lined Pond

Overwintering Frogs: Skimmer Boxes, Heaters & Habitat

Frogs in a lined pond (no soil) attempt to hibernate in the skimmer box. Annual losses suggest the setup fails to provide stable, oxygenated winter refuge.

Why They Choose the Skimmer

• Warmer (pump motor heat).
• Water movement = oxygen.
• Protection from freezing solid.

Better Winter Refuge Design

1. Submerged Heater in Skimmer: 50–100W aquarium heater with thermostat set to 40°F. Keeps water liquid, oxygenated.
2. Deep Zone with Leaf Litter: Add 6–12" of oak/maple leaves in deepest area (if >18" deep). Frogs burrow in mud/leaves.
3. Aerator at Mid-Depth: Air stone 12" off bottom. Adds oxygen without supercooling.
4. Frog Hibernaculum: Bury a perforated 5-gal bucket on its side, filled with leaves/sand, near pond edge. Natural, insulated.

Feeding? Generally No.

Frogs don't eat during hibernation. Metabolism near zero. Feeding pollutes water. Only offer food (crickets, worms) if active in warm spells.

Tadpole Overwintering

Some species (bullfrogs, green frogs) overwinter as tadpoles. They need deep, oxygenated water. Same aerator/heater helps.

Your lined pond lacks natural mud—create artificial refuges. A heated skimmer + leaf litter zone + aerator = high survival.