Can I plant this in my pond?

It is strongly discouraged due to its invasive nature and potential to escape into local waterways.

How do I get rid of it?

Mechanical removal is common, but you must ensure every fragment is collected to prevent regrowth.

Plant guide

Eurasian watermilfoil.

Myriophyllum spicatum

Pronounced my-ree-oh-FY-lum spy-KAY-tum

Also known as Eurasian Water Milfoil, Eurasian Water-milfoil, Eurasian Watermilfoil, Eurasian spiked water-milfoil, Spike Water-milfoil, Spike Watermilfoil, Spiked Water Milfoil, Spiked Water-Milfoil

Myriophyllum spicatum — Photo by chiuluan (CC BY) via gbif

This is a submerged aquatic plant that grows in still or slow moving water. It is known for its ability to form dense mats near the surface. Please be aware that it is considered an invasive species in many parts of North America.

At a glance

Care level: Easy
Plant type: Aquatic perennial
Light: Full sun to partial shade
Indoor light: Bright indirect
Water: Every 0 days
Mature size: 3 to 10 feet
Growth rate: Fast
Hardiness: USDA 4 to 9
Bloom time: Mid to late summer

Care

This plant thrives in nutrient rich water and requires plenty of light to grow well. Keep an eye on its spread, as it can quickly overtake an entire aquarium or pond. It is best kept in controlled environments to prevent escape into local waterways.

Watering: This plant must be kept fully submerged in water at all times.
Feeding: Add liquid aquatic fertilizer if the water column lacks sufficient nutrients.
Pruning: Trim back stems regularly to keep the plant from crowding out other species.
Repotting: Divide the root mass if the plant becomes too dense for its container.
Soil: Aquatic substrate
Soil pH: 6.0 to 9.0
Temperature: 0 to 30°C
Humidity: 80 to 100%

Safety

People: There is no known toxicity, but it is not meant for consumption.
Children: Keep children away from stagnant water where this plant grows to avoid drowning risks and waterborne pathogens.
Edibility: This plant is not considered edible and may be contaminated by polluted water.

How to identify it

Feathery whorled leaves
Four leaves per whorl
Long submerged stems
Emergent flower spikes
Reddish stem tips

Height: 0.3 to 3m
Spread: 0.3 to 1m
Leaves: green, deciduous
Flowers: red, yellow, 0.5 to 1cm
Fruit: brown, Autumn

Problems to watch for

Algal blooms · Dense mats of the plant can trap nutrients and promote excessive algae growth.

By symptom

Plant problems by symptom

Check your eurasian watermilfoil from a photo

Pocket Botanist looks at a photo of your plant and tells you what's wrong and what to try first.

Growing it

Propagation: cuttings, fragmentation
When to plant: spring, summer

Avoid planting this with native aquatic species as it will aggressively outcompete them for light and nutrients.

Grows well with

Hornwort · Both are submerged aquatics that provide structural complexity in pond environments.
Water Lily · Water lilies provide shade that can help balance the light levels in a pond.

Similar species

Northern Watermilfoil · It is a native lookalike that is much less aggressive than the invasive species.

Science

Family: Haloragaceae
Genus: Myriophyllum
Order: Saxifragales
Class: Magnoliopsida
Native range: Europe, Asia, and northern Africa.
Conservation: It is considered a noxious weed in many regions and should not be introduced to new water bodies.

It thrives in slow moving or still water by rapidly spreading through stem fragments that root in the sediment.

Value to wildlife: provides cover for small fish, invertebrate habitat
Pollinators: bees
Uses: aquarium plant, pond oxygenator

Through the year

JFMAMJJASOND

Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 6/9
Light: 7/9
Temperature: 5/9
Moisture: 9/9
Nutrients: 7/9

Taxonomy resolved against GBIF.

Questions people ask

Can I plant this in my pond?: It is strongly discouraged due to its invasive nature and potential to escape into local waterways.
How do I get rid of it?: Mechanical removal is common, but you must ensure every fragment is collected to prevent regrowth.

Where the name comes from

The name Myriophyllum comes from the Greek words for myriad and leaf, referring to its finely divided foliage. Spicatum refers to the spike like arrangement of its tiny flowers.

Good to know

It can grow in water up to 10 meters deep.
A single broken stem fragment can grow into a whole new plant.
It was likely introduced to North America via the aquarium trade.

Keep your eurasian watermilfoil growing

This page is a general guide. Save your plant in Pocket Botanist and you get care reminders timed for this plant, plus a care history that shows what worked.

Get the app

This guide was generated with AI on October 19, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.