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Cuscuta californica

California dodder

Convolvulaceae Western United States (California)

Attracts Pollinators

Native to North America

SunFull Sun

WaterLow

Overview

Cuscuta californica is a parasitic annual vine in the morning-glory family, made up of slender, leafless, yellow to orange thread-like stems that twine over and through other plants. It has no functional roots or leaves once established and almost no chlorophyll, so it cannot feed itself; instead it pierces the stems of host plants with small suckers called haustoria and draws water and nutrients directly from them. A seedling germinates in soil, sends up a thin stem that circles until it touches a host, attaches, and then loses its connection to the ground. In summer it produces dense clusters of tiny white to cream bell-shaped flowers about 0.1 inch (2-3 mm) across, followed by small capsules of seed. Heavy infestations form tangled orange mats that can weaken or kill host plants and reduce flowering. It parasitizes a wide range of native shrubs and herbs, especially in chaparral and coastal scrub, and grows in California and the western United States. Because it spreads by seed and by stem fragments, it is hard to remove once it takes hold. It grows wherever suitable hosts and full sun occur, and dies back with its hosts at season end.

Native Range

Native to California and the western United States, extending into adjacent regions, where it grows as a stem parasite on native shrubs and herbs in chaparral, coastal sage scrub, grasslands, and disturbed open ground.

Suggested Uses

This species is not grown ornamentally and has no garden use; it is a parasitic weed of wild and cultivated plants. It appears in natural areas and disturbed ground on its host plants. Information on it is mainly for identification and management rather than planting.

How to Identify

Identified by tangled masses of thin, leafless, yellow to orange stems wrapped around other plants, with no roots or leaves of its own. Small clusters of tiny white bell-shaped flowers appear in summer. The orange threads attach to host stems by small suckers.

Appearance

Size & Dimensions

Height1' - 6'

Width/Spread1' - 3'

Colors

Flower Colors

white

Foliage Colors

yellow

orange

Bloom Information

Bloom Period

~12 weeks

Summer

Flowers in summer, roughly June to September, producing dense clusters of minute white to cream flowers along the parasitic stems. Flowering is followed by small seed capsules. The plant completes its cycle within a single growing season.

Growing Conditions

Sun Requirements

SunFull Sun

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 sand rocky

Drainageaverage

Water & Climate

Water Needs

Low

Care & Maintenance

Care Guide

This is a parasitic plant rather than a garden subject, and it is not cultivated. It germinates in soil, then attaches to a host plant and lives off it for the rest of the season. Where it appears as a pest, removing and destroying infested stems before the plant sets seed limits its spread, since both seed and stem pieces can start new infestations. It depends entirely on living hosts and dies when they die or at the end of the season. It favors full sun and open stands of susceptible plants. No care encourages it in the garden.

Pruning

Management rather than pruning applies to this parasite: infested host stems are cut out and destroyed before seed forms. Repeated removal over a season reduces reinfestation. Clearing affected plants entirely is sometimes needed to break the cycle.