Introduction

A short time ago, in a small area of Long Island pine barrens that was thinned to control the southern pine beetle, native plants thrived and began to fill the gap. Young pitch pine (Pinus rigida), red maple (Acer rubrum), oaks (Quercus spp.), and other native species were establishing themselves in the thinned area. Native species included various members of the Ericaceae family, such as spotted wintergreen (Chimaphila maculata), wintergreen (Gaultheria procumbens), common lowbush blueberry (Vaccinium angustifolium), highbush blueberry (Vaccinium corymbosum), maple leaf viburnum (Viburnum acerifolium), and southern arrowwood (Viburnum dentatum). The pitch pine-oak forest was restoring itself through natural regeneration, with every plant species being native—except for one: tea viburnum (Viburnum setigerum). This invasive species was aggressively crowding out the native plants, threatening the forest’s natural balance.

Identification and Biology

Tea viburnum is a deciduous shrub that grows 8 to 12 feet tall and 6 to 8 feet wide, forming a loose vase shape. It often loses the bottom third of its leaves, giving it a leggy appearance.

The white flowers, arranged in flat-topped clusters (cymes) up to 2 inches wide, bloom in April-May. The flowers are followed by abundant yellow-orange fruits that mature in October to bright red. Berry production is often so prolific that the flexible stems arch downward from the weight.

Tea viburnum has simple, deciduous leaves with an opposite leaf arrangement. This means that the leaves grow in pairs on either side of the stem, directly across from each other. The branches also tend to be arranged oppositely. Leaves are 3 to 6 inches long with a wide, lanceolate leaf shape, pubescent leaf veins and petiole, and blue-green leaf color. The pointed, slightly toothed leaves turn a muted purplish-red in the fall.

The bark is gray and fissuring, with stout, glabrous stems marked by lenticels. It features two types of imbricate buds, both vegetative and reproductive, which are green with red edges.

Tea viburnum prefers well-drained, mildly acidic soil and thrives in full sun to partial shade.

Damage and Concern

Originally native to East Asia, tea viburnum has been introduced to various parts of the world, including the United States, where it can spread aggressively and outcompete native plants. Plants can shade native seedlings and small saplings.

According to EDD MapS, tea viburnum was observed as possibly being invasive in Maryland, northern Virginia, northern New Jersey, southeastern New York State, southwestern Connecticut, and Long Island. 

There have been more than 50 observations of tea viburnum on Long Island to date. Most of New York State has no reports of tea viburnum. The species is not ranked on the New York State Invasive Species Tiers List (https://www.nynhp.org/invasives/species-tiers-table/). Given the high number of observations in the LIISMA region, tea viburnum would likely be ranked as a Tier 3 or Tier 4 here. Tier 3 refers to highly invasive species with medium abundance in the region, with a management goal of containment. Tier 4 refers to a highly invasive species with great abundance in the region, with a management goal of local control.

Other invasive plants that threaten pitch pine-oak forest include Thunberg’s barberry (Berberis thunbergii), multiflora rose (Rosa multiflora), common buckthorn (Rhamnus cathartica), glossy buckthorn (Frangula alnus), and linden arrow-wood, also known as linden viburnum (Viburnum dilatatum).

Management

Tea viburnum can be controlled using a combination of methods, similar to the control of linden viburnum.

Manual control: Cut and remove plants, including roots. Remove any fruiting bodies to prevent seed dispersal. Repeated cutting or treatment with herbicide on cut stumps may be necessary.

Herbicide control: Apply herbicide directly to freshly cut stumps. Always follow herbicide labels, state and local regulations, and best management practices to minimize harm to surrounding vegetation and wildlife.

Early Detection and Rapid Response (EDRR): Regular monitoring of conservation areas can help catch new infestations before they become established and widespread. Your reports matter to us —report this invasive species to iMapinvasives or iNaturalist as soon as you detect it.

Restoration: After invasive plant control, restoring the area with native plants can help prevent invasive species from re-establishing. However, this may not be necessary or preferred if natural regeneration would be effective.

Engagement and Outreach: Educating and training natural resource professionals, community scientists, and landowners can aid in prevention and early detection.

Monitoring & Reporting

Categorized as a somewhat widespread Tier 3 or 4 species, the regional goal for tea viburnum is containment and local control. Its extent within LIISMA is fairly well understood and documented, with many sightings documented throughout the region. Widespread invasive species such as tea-viburnum are primarily a concern when found within relatively uninvaded habitat or within one of the LIISMA ISPZs, or Invasive Species Prevention Zones. If you see this plant or any other invasive species in a priority conservation area, report it on iNaturalist or iMapInvasives. 

iNaturalist is an app and website that can help you record your own observations, identify species, collaborate with others, and access the observational data collected by iNaturalist users. Already using iNaturalist? Join a LIISMA iNaturalist Project to have your invasive species observations automatically uploaded to our projects! Here are some of our projects you can join: Invasive Species in Priority Areas, EDRR Species, LIFERS, Tier 1 Invasive Species, and more!

Want to dive deeper? Check out iMapInvasives to map invasive species like a pro!