Myriophyllum alterniflorum
Myriophyllum alterniflorum · Haloragaceae
The gardener's calendar
Ideal time to plant myriophyllum alterniflorum: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Scientific name
- Myriophyllum alterniflorum
- Family
- Haloragaceae
- Plant type
- Submerged aquatic
- Foliage
- Persistent, very finely divided
- Growth
- Fast
- Hardiness
- Very hardy (zones 3 to 9)
- Origin
- Temperate and subarctic zones of the North
- Natural habitat
- Lakes, peatlands and oligotrophic watercourses
Care
Submersion and water circulation
Your alternate-flowered watermilfoil must remain completely submerged in clear, soft, slightly acidic water. Ensure gentle but regular water circulation to prevent stagnation and sediment buildup. In an aquarium, an appropriate filtration system and weekly partial water changes promote growth. This plant tolerates cold, oligotrophic waters (nutrient-poor) very well.
Light exposure
Watermilfoil prefers moderate to good light (10 to 12 hours per day). It adapts to partial shade conditions but grows faster with suitable lighting. In an aquarium, LED lighting of 8 to 10 hours daily is sufficient to maintain balanced growth. Avoid prolonged direct intense light that could encourage algae.
Maintenance and pruning
Trim the upper stems regularly to encourage bushy, dense development. Remove dead or diseased parts as soon as you notice them. In an aquarium, this plant tolerates pruning well and propagates easily by planting stem cuttings in the substrate or letting them float.
Nutrition
Alternate-flowered watermilfoil typically obtains its nutrients through its roots in the substrate. Occasional liquid fertilizer or fertilizer tablets can boost growth, especially in nutrient-poor aquariums. However, in natural oligotrophic environments, the plant thrives without external nutrient supplementation.
Substrate
Plant this species in slightly acidic, sandy or silty substrate with moderate organic matter content. A mix of fine sand and peat promotes rooting in an aquarium. Avoid overly rich substrates that would encourage algae; neutral to slightly acidic water (pH 6.0 to 7.0) is optimal.
Common problems
This plant is generally very disease-resistant. The main issues encountered are algae proliferation due to overnutrition or excess light, and rot in stagnant or warm water. Regularly check that water doesn't stagnate and remove organic debris. Well-oxygenated water and proper hygiene prevent most problems.
Did you know?
Alternate-flowered watermilfoil is a circumpolar species, naturally present in peatlands and cold lakes of Canada, Scandinavia and Russia. Its name alterniflorum refers to the particular arrangement of its tiny flowers in emergent spikes, while the plant itself remains entirely submerged. In aquarium keeping, it is highly valued by Scandinavian enthusiasts for its robustness and delicate aesthetic in cold environments.
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
- Spiked water milfoilMyriophyllum spicatum
- Gonocarpus tetragynusGonocarpus tetragynus
- Parrot featherMyriophyllum aquaticum
- Siberian water milfoilMyriophyllum sibiricum
- Gonocarpus teucrioidesGonocarpus teucrioides
- Gonocarpus micranthusGonocarpus micranthus
Tips generated and checked by Viridia — adapt them to your local climate.