Gratiola Viscidula care guide
Gratiola Viscidula (Gratiola viscidula) — high light, 18-26 °C, pH 5.5-7, CO2 recommended.
Compiled by Aquairi from published sources · Published · Updated
Overview
Gratiola Viscidula (Gratiola viscidula) is an aquatic plant of the family Plantaginaceae, listed in the Aquairi knowledge base as an intermediate-level species. It is typically grown under high light with pressurised CO2 injection on nutrient-rich aquasoil. A compact low-growing stem plant with fine needle-like leaves that form dense cushion-like mats. Under high light, the tips turn reddish, creating a striking gradient effect. Works excellently as a foreground or low midground plant.
Taxonomy
- Family: Plantaginaceae
- Genus: Gratiola
- Scientific name: Gratiola viscidula
- Common synonyms: Sticky Hedge Hyssop
Habitat
Gratiola is a widely distributed genus of small marsh plants (Plantaginaceae) of wet meadows, pond margins and ditches across North America, Europe and Asia. Compact submersed forms are used in foreground aquascapes. In the Aquairi knowledge base, populations associated with this form are recorded from North America.
Growth requirements
- Lighting: high
- CO2: recommended
- Temperature: 18-26 °C (64-79 °F)
- pH: 5.5-7
- GH: 2-10 °dGH
- Substrate: nutrient-rich aquasoil
- Maximum height: 8 cm
- Growth rate: slow
- Recommended placement: foreground
Placement
Foreground or low-midground stem; densely planted portions form a cushion-like low mat, with red tips developing under intense light. In the Aquairi knowledge base this form is recommended for the foreground under high light with pressurised CO2 injection, using nutrient-rich aquasoil.
Propagation
Propagated by cuttings and lateral side shoots; horizontal stems root at every node and quickly extend the carpet. Documented propagation techniques for this entry include: stem cuttings.
Common issues
Low light and shading lead to vertical stretching and loss of compactness; bright light and regular trimming maintain the dense low form.
Propagating Gratiola viscidula by Cuttings
Overview
Gratiola viscidula is a North American stem plant relatively new to the aquarium hobby. Its submersed form has a distinctive, somewhat thorny look, with each stem about 1-2 cm wide. It willingly branches and spreads, forming a very dense fore- to midground cushion that can reach 10+ cm tall but is easily kept low and almost carpeting with regular trimming.
Growth is slow, and under good illumination the bushy tips tighten up. Because the plant branches readily, cuttings are the natural and reliable way to multiply it.
Propagation Method (Cuttings)
Gratiola viscidula is propagated by topping: you cut the upper portion of a healthy stem and replant it, while the remaining base pushes out new side shoots. Over successive trims this turns a few stems into a thick, self-renewing patch.
Step-by-Step
- Select a healthy, upright stem and snip off the top 5-8 cm with sharp scissors.
- Strip the leaves from the lowest 2-3 cm of the cutting to expose bare nodes.
- Plant the bare section 2-3 cm deep into nutrient-rich substrate, spacing cuttings so they fill in into a cushion.
- Leave the trimmed base in place — it will branch into several new side shoots.
- Maintain good light and CO2 so the replanted tops root within roughly one to two weeks.
Conditions for Healthy Growth
Provide medium-to-good light and a medium CO2 level (around 6-14 mg/L) to keep growth compact and the cushion dense; weak light makes the bushy form loose and leggy. A nutrient-rich substrate supports its fibrous roots. Although primarily grown submersed in aquariums, it can also be cultivated emersed, which is a robust way to bulk up stock before flooding.
Trimming & Maintenance
Trim roughly every three weeks. Each trim both controls height and doubles as propagation, since every removed top can be replanted and every cut base branches. Regular trimming is what keeps the plant low and almost carpeting rather than tall and open.
Common Challenges
Its slow growth means patience is required — a dense carpet builds over many trim cycles, not overnight. Insufficient light is the most common reason for a thin, stretched stand. Keep the spreading habit in check near smaller neighbours so the cushion does not crowd them out.