Description

There are four invasive privet species found in Massachusetts. Border Privet, California Privet, Chinese Privet, and European Privet. Privet is a species of flowering plant in the olive family (Oleaceae). In general, these plants are a woody, perenniala plant whose growth dies down annually but whose roots or other underground parts survive, semi-deciduousa shrub or tree which sheds its leaves annually shrub that can grow up to 10 ft in height. It has elliptic or oblong oval leaves measuring 1-2 inches long and 1/3 inch wide. Tip of the leaf can be pointed or blunt. Upper surface is dark green while the lower surface is hairy. It has unpleasantly scented flowers which have nodding panicles measuring 3/4 to 1 1/2 inches long at the tip of branches. Flowers begin appearing in June. Its fruit is berry-like (drupes) that are black to blue-black with a whitish blush at the tip of branches. They are round or nearly round in shape and measure 1/4 inch in length. Fruits appear in September and persist on branches into winter.

Habitat

All four privet species featured here have been reported to be invasive in New England. They thrive in floodplains, fields, disturbed forests, and forest edges.

History and Introduction

There are no species of privet native to the U.S. Privets have been introduced to the U.S. since the 1800s and some species even earlier. They are commonly used as hedges in yards, gardens and other landscapes from which they have escaped and are now well established in the wild.

Threats

Privet may invade roadsides, in old fields and in other disturbed habitats. It can also invade natural areas such as floodplain forests and woodlands. It may displace shrubs in regenerating communities and remain persistent in these areas. Ligustrum ovalifolium can form dense thickets that outcompete many kinds of native vegetation. The shady thickets make conditions unsuitable for native seedlings. Phenolic compounds in the leaves protect plants from leaf-feeding insects which include native herbivorous species.

Dispersal Methods

Spreads by birds that consume fruits and excrete seeds undamaged in new locations; can spread locally through root sprouting.

Control

Do not plant privets. Small plants can be dug out, pulled out by hand or with the help of a mattock or heavy Weed Wrench® type tool. Larger plants can be cut repeatedly or treated with a systemic herbicide. Herbicide can be sprayed on foliage or applied to bark or cut stems and stumps. No biological controls are available for any of these species. Known pests that affect privets include a foliage-feeding insect native to Europe (Macrophya punctumalbum), a fungal leaf spot (Pseudocercospora ligustri) and a common root crown bacteria (Agrobacterium tume-faciens).