Gratiola viscidula

Species description

Care, breeding and tankmates

Plant profile

Placement

Foreground

Its unique, robust appearance makes it an ideal midground plant. It can be shaped into dense bushes that look almost like miniature aquatic conifers. Plant it tightly in groups for the best visual impact.

Botanical form

Stem

Characterized by stiff, short, thorn-like leaves arranged tightly along a thick, rigid stem. It has a very structured, almost geometric appearance. The plant is incredibly sturdy and feels much tougher than typical aquatic stems.

Growth

Slow

Has a relatively slow to moderate growth rate, which makes it easy to maintain once shaped. It doesn't require the constant trimming that many other stem plants do. Higher light and CO2 will modestly increase its growth speed.

Substrate

Medium

Gratiola viscidula develops a short, sturdy root system that anchors firmly in both aquasoils and fine inert gravels. A substrate depth of 4 to 5 centimeters is ideal, allowing its dense, geometric stems to remain upright even during regular trimming. While it can derive a significant portion of its nutrients directly from the water column, a lightly enriched substrate helps maintain the distinctive, rigid structure of its short internodes.

Column fertilization

Recommended

Responds well to regular liquid fertilization, particularly for maintaining its intense green color. Micronutrient dosing is crucial for proper leaf formation. It absorbs nutrients steadily from the water column without being a massive nutrient hog.

Root fertilization

None

Greatly benefits from a nutrient-rich substrate like aquasoil. Strong root development is essential for supporting its thick stems. If using sand or gravel, root tabs are highly recommended to ensure long-term vitality.

Trimming

Occasional

Tolerates aggressive trimming very well and responds by branching densely. You can sculpt it into rounded bushes using scissors, similar to hedge trimming. Replant the sturdy tops to create new, healthy stands.

Propagation

Cuttings

Propagated by simply cutting the stem and replanting the top. The remaining bottom portion will quickly develop multiple new side shoots. Its stiff stems make it very easy to push into the substrate without damage.

Sensitivity

Moderate

Extremely robust and resistant to most common plant issues. It is less prone to melting or lower leaf loss than finer-leaved stems. However, it can be susceptible to black beard algae if flow is poor or organics are high.

Layout role

Midground, Foreground, group

Provides a highly unique, spiky texture that contrasts beautifully with softer plants. It is perfect for creating dense, structured midground focal points. Its 'pine tree' look is often utilized in diorama-style aquascapes.