Species specifics: Huisache

Fast facts about huisache

Huisache is a fast-growing, thorny woody shrub or small tree that can rapidly invade overgrazed or unmanaged pastures.
The species produces large quantities of long-lived seeds with high germination rates, allowing dense infestations to develop quickly after rainfall or soil disturbance.
Young plants can grow aggressively; within just 2–3 years, ranchers may be dealing with trees capable of forming a canopy roughly 10 feet tall if left unmanaged.

What to look for

Huisache (Vachellia farnesiana), also known as sweet acacia, is a thorny shrub or small tree recognized by its dense branching structure, sharp paired thorns and feathery, fern-like foliage.

Mature plants typically range from 6 to 20 feet tall, often forming rounded canopies and dense thickets that compete aggressively with desirable forage species. Young plants establish quickly and can grow rapidly under favorable moisture conditions, making early identification especially important.

Leaves are finely divided and bipinnately compound giving the plant a soft, delicate appearance despite its aggressive growth habit. The branches contain stout white to gray thorns that typically occur in pairs at the nodes.

One of the most recognizable identification features is the bright yellow, puffball-shaped flowers that bloom primarily in late winter through spring, although flowering may occur after rainfall events in warmer climates. The flowers are highly fragrant and often noticeable before the plant itself is spotted from a distance.

Huisache also produces dark brown seed pods that may be slightly curved or constricted between seeds. Seed production is prolific, and seeds can remain viable in the soil for many years. Livestock and wildlife frequently spread seed through manure contributing to rapid expansion across grazing pastures and rangelands.

The plant readily spreads through abundant seed production and fast recruitment. As such, dense infestations can develop quickly when seedlings are not controlled early. Once established, huisache can form thick stands that reduces forage availability and restricts livestock movement.

Huisache is not considered toxic to cattle, however, livestock may browse pods or foliage occasionally, particularly during drought or in limited forage conditions.

Where it is found

The shrub thrives in grasslands, coastal prairies, open rangelands, roadsides, fencerows and recently disturbed or overgrazed areas.

Huisache tolerates a wide range of soil types including sandy soils, clay soils and calcareous sites. It is especially aggressive in overgrazed pastures or areas that have had some type of soil disturbance where seedlings can establish rapidly after rainfall.

Huisache is native to the southern United States and has become one of the most common woody encroachment species in Texas pastures and rangelands. While huisache is most associated with Texas, it has also emerged in other warm southern states including Arizona, Florida, Hawaii, Louisiana and New Mexico.

How to treat it

Huisache’s drought tolerance, rapid growth and ability to resprout after top removal make it a persistent, often multi-year, brush management challenge.

For individual plant treatments, apply Sendero® herbicide at 1% volume/volume with a non-ionic surfactant at 0.25% volume/volume. For broadcast applications, apply Sendero herbicide at 28 ounces per acre with Tordon® 22K herbicide at 32 ounces per acre mixed with a non-ionic surfactant.

Sustainable huisache control program

A long-term, 5-year application program utilizing a combination of treatments is available exclusively through Corteva authorized retailers. The protocol includes three annual treatments within a five year period of a mixture of GrazonNext® HL herbicide at 24 ounces per acre with Tordon 22K at 4 ounces per acre in combination with Escort at 0.4 ounces per acre, or a mixture of DuraCor® herbicide at 12 fluid ounces per acre with Mezavue® herbicide at 8 fluid ounces per acre in combination with Escort at 0.4 fluid ounces per acre.

To get started on this program with a greater than 75% mortality guarantee, contact your local Range & Pasture Specialist.

Tordon® 22K and MezaVue® are Restricted Use Pesticides. Sendero® is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Tordon 22K is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. GrazonNext® HL has no grazing or haying restrictions for any class of livestock, including lactating dairy cows, horses (including lactating mares) and meat animals prior to slaughter. Label precautions apply to forage treated with GrazonNext HL and to manure and urine from animals that have consumed treated forage. Consult the label for full details. GrazonNext HL is not registered for sale or use in all states. GrazonNext HL is not for sale, distribution, or use in New York State and San Luis Valley of Colorado. Under normal field conditions DuraCor® is non-volatile. DuraCor has no grazing or haying restrictions for any class of livestock, including lactating dairy cows, horses (including lactating mares) and meat animals prior to slaughter. Label precautions apply to forage treated with DuraCor to manure and urine from animals that have consumed treated forage. DuraCor is not registered for sale or use in all states. MezaVue is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state Always read and follow label directions.