Overwintering Pond Plants: Watercress & Yellow Floating Heart

Zone 7, shallow pond, light frost damage. Can you save watercress and yellow floating heart?

Watercress (Nasturtium officinale)

• Edible! Harvest remaining leaves for salads/sandwiches.
• It’s an annual/biennial—will not reliably return from roots in a frozen shallow pond.
• Replant next spring from seed or grocery-store cuttings.

Yellow Floating Heart (Nymphoides peltata)

• Invasive Alert: Listed as noxious in many U.S. states. It spreads aggressively via runners and fragments.
• Do Not Overwinter. Remove entirely. Compost away from waterways.
• Replace with native alternatives: Nymphoides aquatica (banana lily) or Hydrocleys nymphoides (water poppy)—check local regulations.

General Zone 7 Plant Preservation

For hardy marginals (iris, pickerelweed, rushes):

1. Cut back to 2–3 inches above crown.
2. Option A: Leave in pond at deepest point (if >18 inches).
3. Option B: Move pots to garage/shed, keep damp, dark, above freezing. No fertilizer.

Tropicals (canna, taro, water hyacinth) must come indoors or be treated as annuals.