The Brazilian Pepper Tree, Schinus terebinthifolia, is an evergreen species originally from Argentina, Brazil, and Paraguay. This plant was introduced to the United States in the mid-1800s as an ornamental tree, prized for its vigorous growth and attractive appearance. While initially valued for landscaping, its ability to thrive in subtropical climates, including Arizona, has led to its widespread establishment outside of cultivation. The tree’s adaptability and rapid spread have transformed it from a garden favorite into a significant environmental concern in many regions.
Identifying the Brazilian Pepper Tree
Accurate identification of the Brazilian Pepper Tree is important for effective management. This species grows as a dense shrub or small tree, reaching heights of up to 30 feet. Its leaves are a key identifying feature, arranged alternately along the stem and pinnately compound, consisting of multiple leaflets. Each leaf has an odd number of leaflets, commonly seven to nine, which are glossy light green, 1 to 2 inches long, and finely toothed. When crushed, the leaves release a distinctive turpentine-like scent.
Small, white flowers appear in clusters from late summer through fall. These flowers are followed by abundant bright red berries. These glossy, spherical drupes ripen in winter and often persist on the tree. The bark of mature trees can appear shaggy, peeling in vertical strips. Distinguishing it from native plants with red berries requires careful observation of these leaf and bark characteristics.
Ecological and Health Impacts in Arizona
The presence of Brazilian Pepper Trees in Arizona poses ecological and health challenges. This aggressive plant forms dense thickets that outcompete and displace native vegetation, reducing local biodiversity. Its rapid growth and ability to colonize disturbed sites, including riparian areas, can disrupt natural ecosystems and impact water resources. The dense monocultures formed by this tree can also alter natural fire regimes, increasing fuel loads and fire intensity.
Beyond environmental degradation, the Brazilian Pepper Tree can affect human health. As a member of the cashew or sumac family (Anacardiaceae), it contains compounds that can cause allergic reactions. Contact with the sap from the bark, leaves, or fruits can lead to dermatitis, characterized by severe itching and skin inflammation. The odors from its flowers can also induce respiratory issues and allergic reactions, such as sneezing and asthma-like symptoms.
Legal Status and Regulations in Arizona
Due to its invasive nature and adverse impacts, the Brazilian Pepper Tree (Schinus terebinthifolia) holds a legal classification in Arizona. The Arizona Department of Agriculture has listed it as a Class A noxious weed. This designation signifies that the plant is either not known to exist or has a very limited distribution within the state, making control a high priority.
This classification carries implications for landowners and the public. The sale, transport, and cultivation of Brazilian Pepper Trees are restricted within Arizona. If found, these plants are subject to quarantine, control, or mitigation efforts to prevent further spread. The Arizona Department of Agriculture can initiate abatement measures in areas infested with Class A noxious weeds if they determine there is a threat to agriculture or horticulture.
Effective Removal and Control Methods
Removing Brazilian Pepper Trees requires a combination of methods, tailored to the plant’s size and infestation extent. Manual removal is feasible for smaller plants, involving hand-pulling seedlings or digging up young trees. Ensure the entire root system is extracted to prevent re-sprouting. Cutting down larger trees is a common initial step, but it must be followed by immediate herbicide application to the stump to prevent regrowth from the root crown.
For chemical control, systemic herbicides like triclopyr or glyphosate are widely used. Cut-stump treatment involves applying herbicide directly to the cambium layer, the living tissue just inside the bark, immediately after cutting the trunk near the ground. This method is most effective when the tree is not fruiting to avoid spreading seeds.
Basal bark treatment applies an oil-soluble triclopyr ester solution to the lower 12 to 18 inches of the trunk. This method works well in the fall when the tree actively translocates nutrients to its roots. Foliar applications, spraying herbicide onto leaves, suit seedlings and saplings but require thorough coverage to prevent drift.
When handling herbicides or plant material, always wear personal protective equipment, such as gloves and eye protection. This minimizes exposure to irritating sap and chemicals.
Prevention and Native Alternatives
Preventing the re-establishment of Brazilian Pepper Trees after removal is a long-term commitment requiring consistent monitoring. Sites where these trees have been removed should be regularly inspected for new seedlings or sprouts for at least six months. Prompt removal of any new growth helps to deplete the seed bank and prevent re-establishment. For areas with extensive infestations, complete soil removal may be necessary to prevent re-colonization.
Replacing removed Brazilian Pepper Trees with native Arizona plants offers a beneficial approach to restoration. Native alternatives are well-suited to the local climate and soil conditions, requiring less water and maintenance. Excellent native tree and shrub options include the Texas Mountain Laurel (Sophora secundiflora), known for its fragrant purple flowers, and the Ironwood, a slow-growing tree. For smaller spaces or screening, evergreen sumac (Rhus virens) and sugar bush (Rhus ovata) provide attractive foliage. Various native cacti, such as cholla and organ pipe cactus, offer aesthetic appeal and provide habitat for local wildlife.