Winterizing Your Pond: A Step-by-Step Guide for Healthy Spring Returns

Closing the pond season is bittersweet—but thorough winterizing protects your liner, fish, and investment. Here's the essential checklist for freeze-prone regions.

1. Bottom Clean-Out

Remove all leaves, sludge, decaying matter. Pond vacuum (large) or hand net (small). Decomposing organics = toxic gases under ice.

2. Plant Management

Annuals (water lettuce, hyacinth, parrot's feather): Compost—nearly impossible to overwinter. Remove before freeze.

Tropicals (canna, elephant ear): Lift tubers, clean, store in peat moss cool/dark.

Hardy Perennials (water lily, iris, rush): Trim to 1–3" above crown. Lower pots to deepest zone (below freeze line). Remove string algae.

Water Lilies: Cut leaves to 1" above crown. Lower if depth allows—leave deepest area for fish.

3. Fish Care

Health Check: Inspect for ulcers, odd coloration. Treat issues now—compromised fish rarely survive winter.

Feeding: Stop when water consistently <50°F. Fish metabolism slows; they'll hover near bottom. Use a $3 pond thermometer.

Predator Protection: With surface plants gone, add hiding spots: prop pots for caves, install koi castles.

4. Equipment Decisions

Pump/Waterfall: Zones 7–10: may run all winter (keeps ice open). Risk: ice damming diverts water out of pond. Monitor daily.

Shutdown: Pull pump if freeze likely. Store per manufacturer (older pumps in water, newer dry).

Gas Exchange (Critical if Fish Present): Maintain one ice hole. Options:

• Aquarium airstone + pump (5" below surface)
• Floating de-icer (100–1500W; buy backup—they fail)
• Cattle trough heater
• Child's bouncy ball (traps warm air)

Never chop ice—shock kills fish. Emergency: pour boiling water to open hole.

5. Winter Vigilance

Check every 2–3 days: ice hole, water level, equipment. Plan next year's upgrades while you watch.

Editor's note: Originally published November 6, 2008. All photos by Susanne Talbert.