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Ludwigia peploides

floating primrose-willow

Onagraceae Warmer Americas

Attracts Pollinators Container Friendly

Native to North America

SunFull Sun – Part Shade

WaterHigh

HardinessZones 8–11

Overview

Ludwigia peploides is a sprawling aquatic perennial that roots in mud at the water edge and sends floating and creeping stems out over the surface, forming dense mats. The glossy, oval to spoon-shaped leaves are 1-4 in (2.5-10 cm) long and clustered along the stems, with inflated white spongy floats sometimes present at the nodes. From late spring through fall it produces bright yellow five-petaled flowers about 0.8-1.5 in (2-4 cm) across, held just above the water on short stalks. It grows in ponds, ditches, slow streams, lake margins, and seasonal wetlands. Native to the warmer Americas, it is listed as an invasive weed in parts of Europe, Australia, and the western United States, where its mats choke waterways and crowd out other plants. The stems root at the nodes and fragment easily, so pieces spread to new sites. The flowers draw bees and the cover shelters aquatic insects.

Native Range

Native to the warmer parts of the Americas, including the southern and western United States, Mexico, and South America. It grows in ponds, ditches, canals, slow rivers, lake edges, and seasonal wetlands, and has spread as an invasive weed in many other regions.

Suggested Uses

In its native range it is sometimes grown at pond margins for its yellow flowers and surface cover. Because it spreads aggressively, it is rarely planted and is removed from many waterways. Where grown, it is confined to contained ponds away from natural water.

How to Identify

Identify by the floating and creeping stems forming mats, the glossy spoon-shaped leaves clustered along them, and the bright yellow five-petaled flowers raised just above the water. White spongy floats may sit at the stem nodes. The five separate petals and floating habit set it apart from native pond plants.

Appearance

Size & Dimensions

Height2" - 6"

Width/Spread3' - 10'

Reaches mature size in approximately 1 years

Colors

Flower Colors

yellow

Foliage Colors

green

Fall Foliage Colors

yellow

Bloom Information

Bloom Period

~20 weeks

Spring Summer Fall

Bright yellow flowers open from late spring through fall, roughly May to October in warm climates, opening a few at a time over a long season. Each flower lasts about a day. Bloom is heaviest in summer when the mats are most active.

Detailed Descriptions

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 6-12 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 8.0(Neutral)

357912

Soil Types

loam clay silt

Drainagewet

Water & Climate

Water Needs

High

Frost Tolerance

tender

Time to Maturity

1-2 years

Care & Maintenance

Care Guide

Ludwigia peploides grows in full sun in still or slow water and saturated mud, rooting at the margin and spreading over the surface, and tolerates a pH of 6.0-8.0. It needs constant moisture or shallow standing water and dies back where water dries completely for long periods. Growth is rapid in warm weather, and mats can double quickly. It is regulated or banned as an invasive aquatic weed in several regions, where planting it is restricted. Pulling stem fragments out fully matters because pieces re-root. Few pests limit it in cultivation.

Pruning

Rake or pull mats regularly through the growing season to keep them from covering the water, taking out all stem fragments since they re-root. Cutting back stems before seed set slows the spread. Removed material kept away from waterways prevents fragments from re-rooting.

Pruning Schedule

summer