Viscum spp.

mistletoe

Europe, Asia, Africa, and Australasia

SunFull Sun – Part Shade

WaterLow

Overview

Viscum spp. is a genus of about 100 species of evergreen hemiparasitic shrubs that grow attached to the branches of trees and other woody plants. The most familiar species, V. album, is the mistletoe of European folklore and the winter holiday trade. Plants form rounded or pendulous bushes 0.3-1 m (1-3 ft) across, branching repeatedly in equal forks, with paired, leathery, yellow-green leaves; a few species are nearly leafless. Rather than rooting in soil, the genus attaches to a host through modified roots called haustoria that penetrate the bark and tap the host water and mineral supply while the green shoots make their own sugars. The small flowers are yellow-green and inconspicuous, with male and female flowers usually on separate plants, and they ripen into sticky one-seeded berries of white, yellow, pink, or red. Birds eat the berries and spread the seeds to new branches, where the sticky coat glues them in place. All parts contain viscotoxins and lectins that are poisonous to people and pets if eaten. Heavy infestations can weaken or deform host trees over time. The genus ranges across Europe, Asia, Africa, and Australasia.

Native Range

The genus is native to Europe, temperate and tropical Asia, Africa, and Australasia, and is absent as a native from the Americas. V. album ranges across Europe and into western and central Asia. Other species occur in African woodlands, Asian forests, and Australian scrub, always growing on the branches of host trees and shrubs.

Suggested Uses

Gathered traditionally for winter and holiday decoration, especially V. album. Of interest in wildlife plantings because the berries feed birds in winter and the clumps shelter insects. Sometimes deliberately established on orchard or amenity trees by enthusiasts, accepting the cost to the host.

How to Identify

Plants appear as rounded evergreen clumps perched on the bare branches of a host tree, most visible in winter when deciduous hosts drop their leaves. The shoots fork repeatedly into equal pairs and carry opposite, thick, narrow yellow-green leaves. Clusters of sticky white, yellow, or red berries and the lack of any connection to the ground distinguish Viscum spp. from foliage growing on the tree itself.

Appearance

Size & Dimensions

Height1' - 3'

Width/Spread1' - 3'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~4 weeks

Winter Spring

The small yellow-green flowers open in late winter and early spring and are easy to overlook. Male and female flowers occur on separate plants, so both must be present near each other for berries to set. Berries ripen the following autumn and winter and can persist on the plant for months.

Detailed Descriptions

Foliage Description

yellow-green

Growing Conditions

Sun Requirements

SunFull Sun SunPartial Shade

Requires 4-8 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

Water & Climate

Water Needs

Low

Time to Maturity

4-5 years to first berries

Care & Maintenance

Care Guide

As a parasite, Viscum spp. is established by pressing ripe seeds onto the bark of a suitable host rather than planting in soil. Apple, poplar, lime, and hawthorn are among the hosts that support V. album, and seeds take hold most readily on young, smooth branches. Germination and attachment are slow, with the first leaves often appearing a year or more after the seed sticks. Once attached, the plant draws water and minerals from the host and needs no separate watering or feeding. Light levels in the host canopy, from full sun to light shade, suit growth. Heavy mistletoe loads can stress the host, so growers limit the number of clumps on any one tree.

Pruning

Unwanted plants are removed by cutting the host branch well below the point of attachment, since the haustoria extend within the wood beyond the visible clump. Cutting only the green shoots leaves the embedded tissue, which resprouts. On valued specimens, clumps are thinned to reduce the drain on the host.