Spiked water milfoil
Myriophyllum spicatum · Haloragaceae
The gardener's calendar
Ideal time to plant spiked water milfoil: set it out when the soil is neither frozen nor waterlogged, and water generously as it establishes.
ID card
- Family
- Haloragaceae
- Type
- Submerged aquatic plant
- Foliage
- Deciduous (disappears in winter depending on conditions)
- Growth
- Very fast
- Hardiness
- Not hardy (frost-sensitive)
- Origin
- Europe, Asia, North Africa
- Water depth
- 0.5 to 3 meters
- Flowering
- June to September (emergent red/pink flowers)
Care
Immersion and water circulation
Spiked water milfoil thrives in soft, slightly chalky to neutral water. Ensure regular water circulation to avoid stagnant water where it can become silted. In an aquarium or small pond, a partial water change each week is beneficial. For natural ponds, the plant adapts to various depths but prefers areas where water remains oxygenated.
Light and sunlight
This aquatic plant needs 3 to 4 hours of direct light daily for optimal growth. In an outdoor pond, partial sun exposure is ideal. In an aquarium, LED lighting for 8 to 10 hours per day is sufficient. Insufficient light will slow its growth and weaken its finely divided foliage.
Trimming and regular maintenance
Pruning is necessary to contain its extremely rapid growth, especially in warm water (above 20°C). Regularly pinching the shoot tips encourages a bushier, denser form. Remove dead or discolored stems that accumulate at the bottom. Frequent trimming also prevents the pond or aquarium from becoming overgrown.
Moderate nutrient supply
Spiked water milfoil draws its nutrients from the water and substrate. Liquid fertilizer can be beneficial in nutrient-poor aquariums, particularly iron and micronutrients. In a natural pond with rich sediment, external fertilizer is generally unnecessary. Avoid over-fertilizing, which promotes filamentous algae.
Substrate and anchoring
This plant prefers a loose, nutrient-rich substrate: fine sand, peat, or gravel. It roots easily and also stabilizes suspended particles. A substrate depth of 5 to 10 cm is sufficient for its fine roots to anchor. Floating without substrate is possible but reduces its vigor and stability.
Resistance and prevention
Spiked water milfoil is generally resistant to fungal diseases. In a closed aquarium, watch for stem rot if water is too low in oxygen or heavily laden with organic waste. Good water circulation and regular cleaning prevent these issues. Maintaining biological balance (aquatic fauna) limits algae proliferation that competes with the plant.
Did you know?
Spiked water milfoil has become an invasive species in several regions outside its native range, particularly in North America, where it forms dense beds that obstruct navigation and smother native biodiversity. Its exceptional regenerative ability from small fragments makes it difficult to eradicate once established. Use this plant with caution and never release it into temperate natural waters.
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
- Myriophyllum alterniflorumMyriophyllum alterniflorum
- 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.