Description

An upright deciduousa shrub or tree which sheds its leaves annually shrub or tree in the Araliaceae family reaching a height of 20 to 40 feet and width of 15 to 30 feet with an irregular, spreading, multi-stemmed form. Coarse, thick stems have sharp prickles and prominent large leaf scars. The stems are covered in spines. Large dark green alternate leaves (2-4 feet long) are bi- or tri-pinnately compound. Leaves are pubescent beneath, with veins running to the ends of the serrations. In fall, leaves turn yellow to reddish purple and may drop early in season. The cream white flowers grow in large panicles and bloom in late summer (July-August). Inflorescence branches from the base. Flowers produce small purple to black berries, taken by birds or dropped early. It suckers from base and spreads.

Habitat

This rapid growing plant prefers sun to partial shade locations. It can grow in a range of soil types but prefers moist, well drained soil. Aralia elata can be found in a variety of different habitat types such as man-made and disturbed habitats, forests, forest edges, shrub land, meadows and fields, shores of rivers or lakes, and landscaping.

History and Introduction

This tropical-looking tree was first introduced to North America in 1830 as an ornamental species from Eastern Asia and Japan through the horticultural trade. Although it likely naturalized shortly after its introduction, the invasive tendencies of Aralia elata in the Mid-Atlantic states were only first observed in the early 2000s.

Threats

The Japanese angelica tree is a large, quick-growing shrub or tree capable of forming dense monotypic standsan area dominated by a single species. Diminishing the diversity of the vegetative communities it invades, this species outcompetes and suppresses native and lower growing plants in both the shrub and herbaceous layer by creating dense shade with its luxuriant foliage. 

Dispersal Methods

As a relatively recent invader in the Northeast, very little is yet known about the reproductive potential of Japanese angelica tree. The species is a prolific producer of viable seed and is capable of vegetative growth as well: a single plant can quickly become a large colony.

Control

As with any other invasive infestation complex, large stands of Japanese angelica tree are best managed via a combination of mechanical and chemical means. Small plants and seedlings can be hand pulled while larger individuals will be best controlled by cut stump treatments towards the end of the growing season. All managed infestations should be monitored for at several years to check for new seedlings and to prevent reinvasion from nearby populations.

If you find that you have a population of the invasive Aralia elata, be sure to cut the flowers off before they turn to fruit. This tree spreads quickly when birds eat the fruit and disperse the seeds.

Mechanical

Hand pulling or digging young plants is effective if performed prior to seed set. Larger individuals must be removed using a weed wrench, however, the species has a tendency to create root sprouts if a significant amount of material is left in the ground.

Chemical

You can paint the top of the cut stem with an herbicide, like triclopyrherbicide used to control both broadleaf and woody plants, to kill the root system. Alternatively, you can wait for the leaves to resprout later in the summer and then spray the leaves with a foliar herbicide, like glyphosatea widely used herbicide that can kill certain weeds and grasses, it works by blocking an enzyme essential for plant growth. Be sure to follow the instructions on the label and be extra cautious when applying herbicide near a wetland.

Disposal

Japanese angelica tree can be chipped and composted unless the plant has already formed viable seed heads, in which case all reproductive parts must be bagged and disposed of.