TankBud

Willow hygro

Hygrophila salicifolia

Also known as Willow leaf hygro, Blue hygro, Hygro blue, Hygrophila ringens

FreshwaterStemCuttingsSide shoots

Willow hygro (Hygrophila salicifolia)
Aquarium Plants Factory · Used with permission

Care at a glance

Light
Medium light
CO2
CO₂ beneficial
Temperature
64–86°F
18–30°C
Max height
23.6 in
60 cm
Growth rate
Fast
Placement
Background
Type
Stem
pH
5.5–8.0
Hardness
2–25 dGH
Spread
5.9 in (15 cm)
Nutrient uptake
Root + water column
Growth region
Submersed or emersed
Difficulty
Easy
Family
Acanthaceae
Origin
Tropical Asian wetlands

Overview

Willow hygro is an undemanding, fast-growing background stem for medium to large tanks. It fills out the rear of a layout or a Dutch-style street.

Did you know

Willow hygro is a strong nutrient sponge, like other Hygrophila. It pulls nitrates from the water fast enough to help starve out algae in a newly planted tank.

Caring for willow hygro

Strip the lower leaves and push the stems into the substrate a little apart. Willow hygro adapts to water from very soft to hard and takes 64 to 86°F (18 to 30°C).

It grows well in medium light without CO2. Added CO2 and a good supply of macro and micro fertilizer speed it up and improve its color. It draws nutrients from both the water and the substrate, so root tabs and a liquid fertilizer both help.

It grows fast. Top the stems and replant the cuttings, which root quickly, and cut side shoots free once they have a few leaves. Trim the stems before they reach the surface. Once a stem grows out of the water it starts to flower, and the submersed growth below it thins out.

Good to know

Willow hygro is a member of the Acanthaceae and is sometimes sold under the name Hygrophila stricta. Its narrow, lanceolate, willow-like leaves give it the common name. Leaf color shifts from medium-light green toward reddish or bluish tones under stronger light.

In the wild

Willow hygro is found in tropical wetlands across Asia, in marshes, ditches and the margins of slow streams. It lives both submersed and emersed. In shallow or open water it readily grows above the surface and bears small light-purple flowers.

Common questions

Does willow hygro 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 willow hygro need CO2?

No, but it helps. Willow hygro can grow without injected CO2, and added CO2 makes it grow faster.

How much light does willow hygro need?

Willow hygro wants medium light. A light sold for planted tanks covers it.

Does willow hygro need root tabs?

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

How do you propagate willow hygro?

Willow hygro propagates by cuttings and side shoots. Cut off the top of a stem and replant it, and the stump left behind grows new shoots. Cut a side shoot off once it has a few leaves and plant it on its own.

How tall does willow hygro grow?

Willow hygro grows to about 23.6 in (60 cm) tall. It grows fast, so expect to trim it often.

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