Groenlandia densa
Groenlandia densa · Potamogetonaceae
The gardener's calendar
Ideal time to plant groenlandia densa: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Common name
- Curly Pondweed
- Family
- Potamogetonaceae
- Type
- Submerged aquatic plant
- Foliage
- Persistent, fine and serrated
- Adult size
- 10 to 30 cm in height
- Growth
- Fast
- Hardiness
- Very hardy (down to −20 °C)
- Origin
- Europe, North Africa and Asia
Care
Immersion and water circulation
Curly pondweed must remain fully submerged in fresh or slightly brackish water. Maintain a water depth of 30 to 100 cm depending on use (pond, aquarium, pool). Gentle water circulation promotes growth and limits debris buildup on the fine leaves.
Light
This plant thrives under moderate to intense light. In an aquarium, 8 to 10 hours of daily light is sufficient. It tolerates partially shaded areas, but grows more vigorously with regular light, ideally 6,000 to 8,000 lumens.
Substrate and rooting
Curly pondweed roots in nutrient-rich substrate: sand, fine gravel or a peat and sand mix. A substrate enriched with nutrients (iron, micronutrients) accelerates establishment and strengthens leaf color.
Fertilisation
In natural environments or unenriched ponds, light fertilisation can stimulate growth. Apply liquid aquatic plant fertiliser every 2 to 3 weeks, or use slow-release pellets. Avoid excess nitrogen, which would promote parasitic algae.
Trimming and maintenance
Regularly pinch stems to encourage compact, bushy growth. Remove yellowed or damaged leaves to maintain vitality. This plant naturally becomes denser and does not require drastic pruning.
Health and prevention
Curly pondweed is not very susceptible to disease if water remains clean and well-oxygenated. Watch for algae proliferation (sign of nutritional imbalance). Excess decomposing organic matter can promote harmful anaerobic conditions.
Did you know?
Curly pondweed is a champion of phytoremediation in temperate wetlands: it absorbs excess nutrients from polluted waters and produces abundant oxygen, making it a valuable ecological ally for restoring ponds and small lakes. This is why it is often used in natural freshwater depollution projects.
Where to buy it
Best planted in spring or autumn, away from frost and heatwaves. Pick a plant with healthy foliage and roots that are not exposed. Best time: March, April, May, September, October.
Add this plant to my garden →Plants from the same family
- Stuckenia pectinataStuckenia pectinata
- Potamogeton perfoliatusPotamogeton perfoliatus
- Zannichellia palustrisZannichellia palustris
- Bog pondweedPotamogeton polygonifolius
- Potamogeton pusillusPotamogeton pusillus
- Potamogeton berchtoldiiPotamogeton berchtoldii
Tips generated and checked by Viridia — adapt them to your local climate.