Camphor tree grows natively in China and Japan where it is used for oils and timber. In 1875 camphor tree was introduced into Florida and established in plantations for camphor production, although it was not profitable for growers.
In Florida, camphor tree is able to rapidly displace native trees and infest forests and other natural areas. This invasive species displaces native plants due to its fast growth habit and the ability to produce large amounts of seed. This seed is readily eaten and spread by birds. Nurseries and garden centers sell camphor tree as a popular ornamental plant which aids in its dispersal in landscaped areas. Camphor tree is not on the Federal or State Noxious Weed List; however it is listed as a Category I species on the Florida Exotic Pest Plant Council (FLEPPC) list of invasive species. FLEPPC considers Category I plants invasive exotic species that displace or disrupt native plant communities, alter the ecology of the environment, or hybridize with native species.
A quick and easy method of identifying camphor is by crushing the leaves or peeling a twig or bark. This will release oils and the scent of camphor. Camphor is an evergreen tree with oval to elliptical leaves, arranged alternately on the stem. Slender twigs are initially green but change to reddish brown. Buds are sharply pointed, roughly 1/2 inch in length. Camphor tree bark is variable, from scaly to irregularly furrowed with flat topped ridges. The camphor tree habit ranges from small to medium (25 to 40 feet tall), but some specimens have attained over 100 feet. Leaf margins are entire, but can be wavy with a shiny, dark green color. Fragrant flowers are greenish white to pale yellow, borne on panicles about 3 inches long. The fruit is dark blue to black, fleshy and approximately 1 to 1.5 cm in diameter. These are produced in large quantities during the winter and spring months in central and north Florida.
Camphor tree can be found throughout Florida, Georgia, and western Texas. Habitats conducive for camphor tree establishment are dry, disturbed areas, such as roadsides. Camphor tree will also invade natural areas. The Florida jujube, Ziziphus celatus, is an endangered native species in Polk County that is being pushed out by camphor tree. Because camphor tree is available in garden centers and nurseries, home-owners are able to purchase plants, ensuring its survival and spread. This species is also spread by wildlife such as birds and other animals that eat the fruit, spreading the seed to different areas.
Preventing the spread and establishment of camphor tree is the first step in a successful management plan. Since the fruit is the primary means of spread, controlling trees before maturation and fruit development is critical. Given this, large trees with heavy fruit potential should be eliminated first. However, since birds vector the seeds, constant monitoring will be necessary to keep this species in check.
Weeds such as camphor tree generally invade open or disturbed areas – following a burn, clearing mowing, etc., so these areas are particularly vulnerable to invasion. Therefore, a healthy ecosystem with good species diversity will help to deter infestation. Given this, disturbed areas should be monitored more frequently and extensively.
Mechanical control is particularly effective on seedling trees when smaller equipment can be used to remove/destroy the plants. Mowing will kill seedling trees and continuous mowing will eventually kill resprouting shoots from a cut-stump treatment. Discing or other mechanical tillage will kill small plants but may encourage subsequent re-infestation due to disturbance. Burning may also provide good control of camphor tree, but repsrouting will likely occur on larger trees. Physical removal of seedlings and young trees is also another tactic, although this may be labor intensive. Care should be taken when removing small trees.
There is limited research and data on biological control of camphor tree.
Chemical control can be separated into cut-stump, basal bark, and foliar treatments. Foliar treatments will work well on young trees, less than 10 feet tall. A dilution of triclopyr (Garlon 3A at 2 to 3% solution or Garlon 4 at 0.5 to 2% solution) in water can be an effective control when applied as a foliar application. Be sure to include a non-ionic surfactant at 0.25% (10 mLs or 2 teaspoons per gallon of spray solution). A 2 to 3% solution of glyphosate (Roundup, etc.) can also be effective, but resprays may be necessary. These herbicides are systemic (move throughout plant tissue) so care must be exercised to minimize off-target damage.
For larger trees, triclopyr (Garlon 4, 30% in oil) is the product of choice. Basal bark treatments are effective for trees up to 6 inches in diameter with smooth bark. Be sure to spray around the entire tree, up 12 inches from the base. For larger trees with thick bark, a frill treatment is recommended. For this application, cut into the bark and peel it back to form a cup. Herbicide can then be poured into the pocket created by the frill. The number of frills per tree depends on tree diameter and herbicide used (see page xx for specific recommendations). Cut-stump treatments are effective on trees of all sizes. Use a 50% solution of triclopyr (Garlon 4) and be sure to coat the entire cambium layer (outer ring of the trunk). This should be applied within 2 minutes of cutting and remove all sawdust and debris from the trunk before applying.
Langeland, K.A. and K. Craddock Burks. 1998. Identification and Biology of Non-Native Plants in Florida's Natural Areas. IFAS Publication SP 257. University of Florida, Gainesville. 165 pp.
University of Florida, IFAS Extension, Circular 1529, Invasive Species Management Plans for Florida, 2008 by
Greg MacDonald, Associate Professor Jay Ferrell, Assistant Professor and Extension Weed Specialist
Brent Sellers, Assistant Professor and Extension Weed Specialist
Ken Langeland, Professor and Extension Weed Specialist Agronomy Department, Gainesville and Range Cattle REC, Ona
Tina Duperron-Bond, DPM – Osceola County
Eileen Ketterer-Guest, former Graduate Research Assistant
For more information and pictures about camphor tree contained in the Langeland/Burks book, Identification & Biology of Non-Native Plants in Florida's Natural Areas, download this Acrobat .PDF file.
One camphor-eradication effort is underway in part of the Ocala National Forest. Here, Bob Dyksterhouse of the Florida Conservation Lodge Foundation's Ocklawaha Prairie Project, points out the girdling and herbicide treatment that was necessary to kill this 100-year-old tree. The FCLF processes dead camphor trees into mulch for use as landscaping material.
The Center for Aquatic and Invasive Plants and the St. Johns River Water Management District are jointly surveying the spread of, as well as determining the cost of eliminating, camphor trees from District-owned lands, where it is quickly invading some of Florida's few remaining virgin forests and wetlands.
Financial support for this web page provided by the St. Johns River Water Management District (FL).
1. Identification and Biology of Nonnative Plants in Florida’s Natural Areas – Second Edition, by K.A. Langeland, H.M. Cherry, et al. University of Florida-IFAS Publication # SP 257. 2008.
2. Strangers in Paradise, Impact and Management of Nonindigenous Species in Florida, Chapter 2: Florida’s Invasion by Nonindigenous Plants: History, Screening, and Regulation, by D.R. Gordon and K.P. Thomas, pp. 21-37. Island Press, Washington, DC, 1997.
3. Invasive and Non-native Plants You Should Know - Recognition Cards, by A. Richard and V. Ramey. University of Florida-IFAS Publication # SP 431. 2007.