Japanese Cress care guide
Japanese Cress (Cardamine lyrata) — medium light, 15-22 °C, pH 6-7.5, no CO2.
Compiled by Aquairi from published sources · Published · Updated
Overview
Japanese Cress (Cardamine lyrata) is a round-leaved plant of the family Brassicaceae, grown as an aquarium plant. A delicate stem plant with round, scalloped leaves that prefers cooler water temperatures. Grows quickly and produces adventitious roots along its stems, giving it a natural, wild appearance. Ideal for cool-water and subtropical setups.
Taxonomy
- Family: Brassicaceae
- Genus: Cardamine
- Scientific name: Cardamine lyrata
- Common synonyms: Chinese Ivy, Cardamine lyrata
Habitat
Cardamine lyrata originates from East Asia, where it grows in freshwater marshes, ditches and slow-moving streams, frequently emersed on seasonally flooded ground.
Growth requirements
- Lighting: medium
- CO2: not required
- Temperature: 15-22 °C (59-72 °F)
- pH: 6-7.5
- GH: 3-12 °dGH
- Substrate: nutrient-rich aquasoil
- Maximum height: 30 cm
- Growth rate: fast
- Nutrient demand: medium
- Recommended placement: midground
- Typical trim interval: 10 days
Placement
In aquascapes this plant suits the midground.
Propagation
Propagation is by stem cuttings replanted into the substrate; daughter plants are separated once they have formed several leaves and visible roots.
Common issues
Pale or stunted new growth usually signals a nutrient or iron deficiency, while algae on older leaves often follows light that exceeds the available nutrients or CO2; correcting fertilisation and trimming affected parts resolves most cases.
Propagating Cardamine lyrata 'Japan' from Cuttings
Overview
Cardamine lyrata 'Japan' is a compact Japanese form of Cardamine lyrata, an aquatic member of the mustard family (Brassicaceae) native to the marshes of eastern China, Siberia, Korea and Japan. It is also known as Japanese cress and Chinese ivy. The 'Japan' selection carries smaller, rounder leaves on a climbing stem and is grown vegetatively to keep that compact habit.
The species grows rapidly under good conditions and forms an attractive, bushy plant. Because it propagates easily by cuttings, the cultivar is multiplied entirely from stem pieces rather than seed.
Propagation Method (Cuttings)
Cardamine lyrata propagates easily by cuttings. The stem roots from its nodes, so a cut section replanted in the substrate readily develops new roots and continues growing, while the base sends out side shoots.
Step-by-Step
- Select a healthy stem with several leaf nodes.
- Cut the top 5-10 cm just below a node, where rooting is strongest.
- Strip the lowest leaves to expose one or two bare nodes.
- Push the bare nodes gently into the substrate so they can root.
- Keep the base planted; it will branch into new shoots over time.
Conditions for Healthy Growth
As an aquarium ornamental, Cardamine lyrata needs a supply of cool, slow-moving water and strong light. It suits coldwater and subtropical scapes and tolerates a wide hardness range. High levels of carbon dioxide speed growth, though CO2 is not strictly required.
- Lighting: medium to strong; brighter light keeps the form compact.
- Water: cool and slow-moving; temperature 15-26 C and not exceeding about 28 C.
- CO2: optional; added CO2 speeds growth.
- Substrate: any; pH 6-7.8; GH 4-16.
- Difficulty: beginner-friendly.
Trimming & Maintenance
Trim about every two weeks to keep the bushy form and prevent the climbing stems from sprawling. Each trim provides ready cuttings. The plant can grow emersed as well as submersed, and its emersed growth is robust; for the aquarium it is kept submersed. In open ponds keep water below roughly 28 C.
Common Challenges
- Leggy, stretched stems under weak light.
- Decline in water that stays too warm above about 28 C.
- Sprawling growth if not trimmed regularly.
- Slow establishment if cuttings have no intact node to root from.
Propagating Cardamine lyrata: Node-Rooting Cuttings
Overview
Cardamine lyrata is a fast-growing stem plant with round, scalloped leaves that demands cool, slow-moving water and strong light, and cannot survive above roughly 28C. It produces adventitious roots along its stems, giving a natural, bushy look, and is a popular choice for cool-water and subtropical aquariums.
Propagation Method
It propagates easily by cuttings. Because the stems readily form roots at their nodes, a cut section will root quickly whether planted or left to float, so cuttings are the only method you need.
Step-by-Step
- Select a long, healthy stem, ideally one already showing fine roots at its nodes.
- Cut a section several centimetres long with clean scissors, just below a node.
- Remove the lowest pair of leaves to expose a clean node.
- Plant the cutting in nutrient-rich substrate, or simply let it float so it roots at the nodes.
- Once a floating cutting has rooted, plant it where you want a new bushy clump.
Conditions for Healthy Growth
Give it cool, slow-moving water and strong light for the best, bushiest growth; keep temperatures below about 28C, ideally in the 15-22C range. CO2 demand is moderate and added CO2 accelerates development, but it grows quickly in nutrient-rich substrate even at modest levels.
Trimming & Maintenance
Because it grows fast, trim frequently, roughly every ten days, topping stems before they reach the surface. Every top you remove is a ready-made cutting, so trimming and propagation happen in the same step.
Common Challenges
Warm water is the main killer: above roughly 28C the plant declines and dies, so it is unsuitable for tropical tanks. Weak light or stagnant warmth leads to leggy, sparse stems rather than a bushy habit.