Potamogeton gayi

Also known as Gay's pondweed

FreshwaterStemRunnersCuttings

Potamogeton gayi (Potamogeton gayi) — Buce Plant · Used with permission

Care at a glance

Light: Medium light
CO2: CO₂ beneficial
Temperature: 64–82°F; 18–28°C
Max height: 23.6 in; 60 cm

Growth rate: Fast
Placement: Background
Type: Stem
pH: 6.0–8.0
Hardness: 0–30 dGH
Nutrient uptake: Root + water column
Growth region: Submersed
Difficulty: Easy
Family: Potamogetonaceae
Origin: Southern South America (southern Brazil, Argentina)

Overview

Potamogeton gayi is a robust, easy pondweed for the background. It suits breeding tanks and low-tech setups.

Did you know

Unlike almost every other aquarium regular, Potamogeton gayi cannot grow above water at all.

Caring for Potamogeton gayi

Strip the lower leaves and plant the stems a little apart in the background. Potamogeton gayi spreads by underground runners and will wander. Keep it a hand's width away from slow carpets, and pull stray shoots when you thin it.

It grows in soft or hard water and needs no CO2, though injection speeds it up. Medium light suits it, and stronger light colors it toward orange-brown. Root tabs and a liquid fertilizer feed both its roots and its leaves.

It grows fast into a dense stand. Trim tall stems and replant the tops, or cut a runner plant free once it has roots. Coming from a cool subtropical climate, it does fine in an unheated indoor tank. Its range is 64 to 82°F (18 to 28°C).

Good to know

Potamogeton gayi is a pondweed in the family Potamogetonaceae. It is named for Claude Gay, the French botanist who documented the flora of Chile. Its soft, translucent, linear leaves are 4 to 12 cm long but only a few millimeters wide. They sit in two alternate rows along the stem.

In the wild

Potamogeton gayi is native to still and flowing waters of subtropical southern South America, in southern Brazil and Argentina. Winters there are distinctly cool. Thin rhizomes creep through the bottom and send up vertical leafy stems that can reach a meter in the wild.

Common questions

Does Potamogeton gayi need to be planted in the substrate?

Yes. Strip the leaves from the lower part of each stem, then push the stems into the substrate one at a time, a little apart.

Does Potamogeton gayi need CO2?

No, but it helps. Potamogeton gayi can grow without injected CO2, and added CO2 makes it grow faster.

How much light does Potamogeton gayi need?

Potamogeton gayi wants medium light. A light sold for planted tanks covers it.

Does Potamogeton gayi need root tabs?

They help. Potamogeton gayi takes nutrients through both its roots and its leaves. Root tabs near its roots and a liquid fertilizer cover both.

How do you propagate Potamogeton gayi?

Potamogeton gayi propagates by runners and cuttings. New plants grow along its runners. Cut one free once it has roots and plant it. Cut off the top of a stem and replant it, and the stump left behind grows new shoots.