TexasInvasives.org - Home

• MAP & PRIORITIZE: Create priority ratings of invasive species. Newer infestations and smaller plants require much less time than extensive and dense infestations.


• TREATMENT PLAN & MAINTENANCE: Devise both a short- and long-term plan including both specific infestation treatment regimens and ideas for how these fit into a general land management plan.


• REHABILITATION: An eradication and rehabilitation program for specific invasive plant infestations usually requires several years of treatment and many more years of surveillance.

• EDUCATION: Inform users of your land about the invasive plants that pose major threats and important prevention measures. Require all individuals to follow sanitation procedures when working on or near infested lands.


• TAKE INVENTORY: Map invasive plant locations and sites at risk, inspect the site and infestation before operations.


• CLEAN YOUR GEAR: Establish sanitation procedures to prevent the spread of invasives. Require all individuals to follow these procedures when working on or near infested lands:
  
  1. VEHICLES: Avoid driving vehicles, mowers, all-terrain vehicles or spray equipment through infestations in seed or fruit.
  2. CLOTHES: Brush and wipe all seeds and debris from clothes, boots, socks, and personal protective equipment.
  3. CROP MACHINES: Clean motorized equipment, especially the undercarriage and tire surfaces.
  4. BAG IT UP: Always cover trailer-loads or bag invasive plants before transport.


• MONITOR: Employ the search, survey, inventory, monitor and surveillance method. Make repeated visits and record progress of treatments, or the lack of it. Monitor burn pile areas for new seedlings and be careful not to disturb areas where there is a high probability of invasion.

• Rehabilitate, restore or reclaim lands treated by re-seeding with native plants. This promotes invasion resistance by encouraging native diversity and ecosystem function. Treatment schemes for rehabilitation use an integrated approach that combines treatments in an appropriate sequence and at crucial times.

Healthy landscapes start with good cultural practices that strengthen native plant communities and reduce invasive plant pressure. These methods work with natural processes to manage vegetation while minimizing chemical use. Careful planning is needed to avoid impacts on soil, wildlife, and native species.

Prescribed Burning

• Best for: Fire-sensitive species that don’t re-sprout.
• Timing: Winter or early spring burns work well for invasive forbs; summer burns help control King Ranch bluestem.

Water-Level Manipulation

• Bonus: Lower water levels in spring or summer can help time herbicide applications.

Prescribed Grazing

• Best for: Palatable, non-toxic invasive species.
• Tips: Choose the right animal for the job and manage grazing carefully to avoid harming native plants.

MANUAL REMOVAL: Pull or cut using hand tools such as saws, loppers, or weed-wrenches.

• Works best for small or young woody plants.
• Remove roots completely to prevent regrowth.
• Combine with herbicide if resprouting occurs.

MULCHING: Apply mulch or ground cover to suppress weeds and protect soil.

• Reduces erosion and helps retain moisture.
• Use weed-free, native-safe materials.
• Avoid use below high-water lines or near waterways.

SOLARIZATION: Cover infested areas with dark plastic sheeting to trap heat and kill invasive plants or invasive soil invertebrates.

• Best for small areas and summer treatments.
• Effective where herbicides can’t be used and stop invasive soil invertebrates from establishing in your yard.
• Quickly replant treated soil to prevent reinvasion.

Mechanical methods use tools and machinery to remove or cut invasive plants. When used carefully, they can boost the effectiveness of other treatments and prepare sites for restoration.

HOW TO: Cut, uproot, or grind invasive plants using the right equipment for the job.

• Choose tools that match the site and minimize soil disturbance.
• Follow up with herbicide or reseeding to prevent regrowth.
• Avoid heavy machinery near streams, wetlands, or karst features




Common Tools & Techniques

• Skid-Steer Loaders – Great for dense infestations and tight spaces. To reduce soil damage, use wheeled models.
• Mulchers – Mulchers are increasingly preferred for reducing both invasive and native woody plants in dense infestations. Quickly clear dense woody plants and prepare sites for follow-up burning or herbicide treatment.
• Bulldozers – Useful for large infestations but can cause significant soil compaction. Use with caution and limit passes.

Biological control of plants uses living organisms to weaken, kill, or stop seed production of the targeted plant. The most common agents in bio-control programs are insects and pathogens. The use of nematodes and mites are under study. See individual species pages for more information and examples.

When other techniques are not sufficient, herbicide can offer an alternative. Effective herbicide applications can kill roots without exposing soil; Exposed soil is susceptible to reinvasion and erosion. Consider herbicide toxicity to non-target species and persistence, activity and mobility in soil or water before applying any chemicals. For successful herbicide treatments:

• Select the least toxic herbicide that is effective for the target species and appropriate for the landscape.
• Follow application and mixing requirements prescribed on the label and use the most directed application method that will be effective.
• Consider plant vulnerability and weather conditions. Many herbicides are effective only when plants are actively growing, so periods of drought, cold or heat may render pesticides ineffective. Uptake of foliar application may be hindered when leaf stomata are closed due to high temperatures.
• BE PATIENT. Allow herbicides to work for several months before re-treating them. An applicator should NEVER “double the rate for better results” and NEVER deviate from strict label application rates.

Water Quality Protection

Water quality is an important environmental issue in relation to pesticide use. However, many of the concerns tied to pesticide use can be reduced through common-sense practices.

Contamination risk to ground and surface water is influenced by:

• How strongly a pesticide binds to soil (or organic matter);
• Its solubility in water;
• Degradation rate and Volatility.

Soil characteristics and chemical mobility determine how quickly pesticides move toward groundwater; clay- or organic-rich soils bind herbicides more effectively. To reduce runoff risk, avoid applying products within 48 hours before expected heavy rainfall. Minimize spray drift by:

• Spraying only on calm days and adding drift-control agents.
• Using lower pressure and larger droplet sizes.
• Limit broadcast (spraying) methods in favor of directed (painting/basal) methods.

PROPER DISPOSAL of herbicides limits contamination:

• Mix only the amount you need.
• Triple-rinsing containers, never near waterways.
• Applying rinse water to the treated area, never near waterways.
• Following label directions for container disposal.

Directed foliar Sprays and Wipes

Directed foliar sprays apply herbicide mixes to foliage (i.e.: leaves) to wet the leaves and growing tips/areas of target plants.

• Effective for treating many herbaceous and woody invasive species, typically midsummer–late fall; some species require winter/spring treatment to prevent seed formation.
• Allows selective application by aiming at target plants and avoiding desirable vegetation; spray shields improve precision.
• Use only foliar-active herbicides to avoid unintended root-zone injury from soil-active chemicals.
• If non-target foliage is accidentally sprayed, remove affected leaves to prevent herbicide uptake.
• Low-volume sprays (20–30 psi) reduce drift; wind under 10 mph is required, with 5–10 mph preferred. High-volume systems are efficient for large infestations with few non-target plants.
• Wick/roller applicators apply ultra-low volumes for maximum selectivity, especially near rare or sensitive plants. Vehicle-mounted wipe bars can be used to selectively target large areas of taller target species (e.g.- Johnsongrass) with minimal impacts to shorter desirable species.

Basal Sprays and Wipes

Basal sprays apply herbicide-oil mixtures to the lower stems of woody plants using sprayers or wicks.

• Formulations must be oil-soluble and mixed with basal oil, penetrants, diesel, fuel oil, mineral/vegetable oils, or blends.
• Most effective June–September; winter treatments may be easier when leaves are absent.
• Avoid contact with desirable trees or heavy use within their root zone.
• Do not disturb plants treated for at least 2 years due to prolonged root-system herbicide activity.

Stem Injection (including Hack-and-Squirt)

Involves injecting herbicide concentrates or mixtures into downward cuts spaced around the stem. Provides selective control with minimal impact to surrounding vegetation.

• Effective for large trees, shrubs, and vines; less effective for multi-stemmed species.
• Cuts must penetrate bark and cambium but should not be stacked vertically, which hinders herbicide movement.
• A full girdle is unnecessary and should be avoided.

Cut-Treat or Cut-Stump

Herbicide mixtures are applied immediately to freshly cut stumps or stems to prevent resprouting.

• Cuts must be made as low to the ground as possible, and herbicide applied right away. Remove sawdust to prevent herbicide deactivation.
• For stumps >3 inches, wet the entire outer edge thoroughly; for smaller stumps or clumps, wet the entire top surface.
• Some labels require treating the outer stump down to the ground.
• ADD DYE to provide additional color so you can see where you have painted with herbicide.

Broadcast Herbicide Applications

Broadcast application of pesticides should be avoided. The Texas Agricultural Extension provides recommended chemical lists for acceptable broadcast uses. However, in rare cases in which broadcast application is deemed appropriate, choose chemicals with:

• Low non-target toxicity
• Low mobility
• Short environmental half-life

The combination of various manual, mechanical, and chemical methods is often the Best Management Practice for cost-effective and environmentally safe management. Use herbicides only when manual and mechanical methods alone are not enough. Use chemicals safely and effectively by pairing them with other control methods, adhering to label directions, and following state regulations. ALWAYS READ AND FOLLOW THE PESTICIDE LABEL — IT’S THE LAW.

• In Texas, TDA requires applicators to be licensed and meet the following when using regulated herbicides:
• Must have a current pesticide-applicator license (commercial or noncommercial) to apply regulated or restricted-use products. Texas Agriculture+2Texas Agriculture+2
• A “Herbicide Spray Permit” may be required for certain regulated herbicides; you’ll need to submit the form and obtain the permit number before application. Texas Agriculture
• Pesticide dealers must keep distribution records, and applicators must keep application records for at least two years. Texas Agriculture+1
• Applications must comply with buffer and groundwater protection rules. For example, volatile herbicides cannot be sprayed under certain wind or within a 4-mile radius of susceptible crops.

Once invasive species are removed, plants and animals can recover. However, natural recovery processes can be overwhelmed by invasive species and restoration is required. Although restoration efforts have common elements, each area is unique. Work must be guided by site-specific considerations and analysis. However, some generalizations can be made. When soil is disturbed, and especially if it is left bare, it must be revegetated with appropriate species to prevent soil loss and reinvasion. Below is a discussion of some of the factors to consider in a restoration project, followed by a generalized protocol for rapid revegetation of an upland site.

The goal of restoration is to restore ecosystem process, not simply to replace components. Ecosystem processes allow natural systems to repair themselves and to remain relatively stable. The primary processes of concern to a manager are hydrology, nutrient cycling and energy capture. In practice, the assessment and repair of these processes begins with the soil. In the process of treating and removing invasive species, the soil may be disturbed and left bare. In some cases, compaction reduction activities (raking, tilling, disking, ripping) and organic soil amendments may be needed to restore soil to a useful state. In all cases, soil should be protected. Revegetation with appropriate native species provides permanent protection, but in some cases temporary soil protection measures such as mulch may be needed before the site can be revegetated.

Generalized revegetation protocol:

• Address soil disturbance. Compacted soils will need to be loosened as appropriate prior to seed addition.
• Bare soils should be seeded or otherwise stabilized within 15 calendar days of disturbance to prevent erosion and reinvasion. Denuded areas that are inactive and will be exposed to rain for 30 days or more should also be temporarily stabilized, usually by planting seeds and establishing vegetation during favorable seasons in areas where vegetation can be established. In very flat, non-sensitive areas with favorable soils, stabilization may involve simply seeding. Mulching and/or sodding may be necessary on moderate to steep slopes, more erosive soils, or more sensitive areas.
• Appropriate native plant material should be added as seed, live plantings or a combination. Plants vary as to climatic adaptability, soil chemistry and plant growth characteristics (Berglund, 1978). USDA Soil Service technical guides at the statewide level are excellent sources of information for seeding mixtures and planting prescriptions (Hynson et al., 1982). The U.S. forest Service, State foresters and County Extension agents can also provide helpful suggestions (Kochenderfer, 1970). Locally, the Grow Green guides provide a useful resource. In addition to selecting a seeding mixture, the seeding rate must be determined so that adequate soil protection can be achieved without excess cost of overseeding. Berglund (1978) describes how to determine seeding rates in Seeding to Control Erosion along forest Roads.
• In riparian areas, special consideration should be given to species’ contributions to bank stability and water quality. Many species found in central and southwest Texas have been given draft stability ratings based on their contribution to bank stability (Nelle 2009), ranging from 1 (bare ground) to 10 (anchored rock). Ideally, riparian areas will be dominated by plants with stability ratings between 6 and 9. Stability ratings of 7 or higher are considered to be the minimum for acceptable bank stability. However, combinations of species, particularly woody species in association with grasses or sedges, can provide higher stabilities than reflected in individual species ratings (Nelle 2009). In addition to stability ratings, US fish and Wildlife Service wetland indicator status should be considered. Riparian areas should contain a mix of obligate wetland (always occurs in wet areas), facultative wetland (frequently occur in wet areas) and facultative species (equally likely to occur in wet and non-wet areas), dependent on water availability. Perennial waterways can support a larger complement of obligate and facultative wetland species and intermittent waterways will require a higher proportion of facultative species. Regardless of the mix, it is important that all riparian areas contain some species from the facultative groups to provide stability as water availability fluctuates (S. Nelle pers. comm).
• On steep slopes, incorporate native woody plants planted in rows, cordons or wattles.
• Seed during optimum periods for establishment, preferably just prior to spring or fall rains (Larse 1971). Most forbs must be sown in the fall; grasses can be sown in either the spring or fall. Supplemental irrigation, if feasible, during the establishment phase will increase germination and survival. During non-growing seasons, apply temporary surface stabilization methods to control surface erosion. Possible methods include mulching (without seeding) and installation of commercially produced matting, blankets and wattles.
• Mulch as needed to hold seed, retard rainfall impact and preserve soil moisture (Larse 1971).
• Amend soil according to site specific conditions.
• Protect seeded areas from grazing and vehicle damage until plants are well established.
• Inspect all seeded areas for failures, and make necessary adjustments.

• Balcones Canyonlands Preserve Land Management Plan, Tier IIA, Chapter 4 Vegetation Management (BCPP). 2007. Balcones Canyonlands Preserve. Austin, Texas, U.S.A.
• Batcher, M.S. 2000. Element Stewardship Abstract for Ligustrum spp. Prepared for The Nature Conservancy. http://www.imapinvasives.org/GIST/ESA/index.html
• Bogler, D. J. 2000. Element Stewardship Abstract for Sapium sebiferum Chinese Tallow- Tree, florida Aspen, Popcorn Tree. The Nature Conservancy, Arlington, Virginia.
• Bugwood Wiki. http://wiki.bugwood.org/.
• Conrad, W., K. Thuesen, M. McCaw, G. Gillman, and G. McGlamery. 2006. Integrated Pest Management Plan: Water Quality Protection Lands Program (WQPL). City of Austin, Austin Water Utility, Tx.
• Findlay R. 1975. Potential menace of Johnsongrass. New Zealand Journal of Agriculture 130: 40-41.
• Fitzwater, WD. 1988. Solutions to urban bird problems. Proceedings of the thirteenth vertebrate pest conference, University of Nebraska. 254-259. http://digitalcommons.unl.edu/vpcthirteen/52
• Floridata. http://www.floridata.com/index.cfm.
• Gilman, E.f. and D.G. Watson. 1994. Pistacia chinensis: Chinese Pistache. fact Sheet ST-482. US forest Service.
• Gleason, J. and G. Taffinder. 2007. Stormwater Pond Dam Safety Program, Integrated Pest Management Plan. Watershed Protection and Development Review Department.
• Global Invasive Species Database. http://www.issg.org/database/welcome/.
• Harmoney, K.R., P.W. Stahlman and K.R. Hickman. 2007. Suppression of Caucasian old World Bluestem with Split Application of Herbicides. Weed Technology 21(3), p. 573-577.
• Holm L., P. Donald, J. Pancho and J. Herberger. 1977. The world’s worst weeds: distribution and biology. The University Press of Hawaii, Honolulu, Hawaii. 609 pp.
• Integrated Pest Management Plan, Town Lake Trail System: Woodland Systems. 2004. City of Austin, Tx.
  Kaufman, S.R. and W. Kaufman. 2007. Invasive Plants: A Guide to Identification, Impacts, and Control of Common North American Species. Stockpile Books, Mechanicsburg, PA.
• Level II Contract Criteria, Vegetation Control Services. City of Austin, Tx.
• Lindsay, H. Personal communication from Helen Lindsay, Motuora Restoration Society. http://www.motuora.org.nz/. Email received 07/29/11.
• Lindsay, H. (2006). Report on weed control programme Motuora 2005/2006. Unpublished report for the Department of Conservation, Auckland Conservancy, Auckland.
• Miller, J.H, S.T. Manning, and S.f. Enloe. 2010. A Management Guide for Invasive Plants in Southern forests. USDA forest Service, Southern Research Station. General Technical Report SRS– 131.
• North Carolina State University. Plant fact Sheets. http://www.ces.ncsu.edu/depts/hort/consumer/factsheets/.
  PBS&J Consulting. 2010. Integrated pest management plan aquatic vegetation management Lake Walter E. Long Decker Creek Power Plant Travis County, Texas. Document No. 080113
• PESTMAN. http://pestman.tamu.edu/.
• Queensland Government, Primary industries and fisheries. Accessed December 2011. http://www.dpi.qld.gov.au/4790_7225.htm
• Ramos, R. and T. Houtman. 2010. City of Austin Parks and Recreation Department: Integrated Pest Management Program. Austin, Tx.
• Robinson, R.C. 2009. Invasive and Problem ferns: A European Perspective. International Urban Ecology (4), p. 83-90.
• Ruckstuhl, E. Dirty Dozens: Holly fern. Bayou Preservation Association. Accessed 29 July 2011: http://www.bayoupreservation.org/html/BPA_exotics.pdf
• Silve, L., C.W. Smith. 2006. A quantitative approach to the study of non-indigenous plants: An example from the Azores Archipelago. Biodiversity and Conservation (15), p. 1661–1679.
• Simmons, M.T. 2005. Bullying the Bullies: The Selective Control of an Exotic, Invasive Annual (Rapistrum rugosum) by oversowing with a Competitive Native Species (Gaillardia pulchella). Restoration Ecology 13: 609–615.
• Simmons, M.T., S. Windhager, P. Power, J. Lott, R.K. Lyons, and C. Schwope. 2007. Selective and Non- Selective Control of Invasive Plants: The Short-Term Effects of Growing-Season Prescribed fire, Herbicide, and Mowing in Two Texas Prairies. Restoration Ecology 15(4), p. 662–669.
• Texas Agriculture Code , House Bill 338. 2011. Chapter 71, Subchapter D, Section 71.154. Disclaimer Required: “This plant list is only a recommendation and has no legal effect in the state of Texas. It is lawful to sell, distribute, import, or possess a plant on this list unless the Texas Department of Agriculture labels the plant as noxious or invasive on the department’s plant list.”
• Texas Department of Transportation. Approved Chemicals for Right of Way Vegetation Management. http://onlinemanuals.txdot.gov/txdotmanuals/veg/approved_chemicals_for_right_of_way_vegetation_ management.htm
• Texas Invasives. http://www.texasinvasives.org/.
• Texas Parks and Wildlife Department (TPWD). 2003. Performance Report: Walter E. Long Reservoir. Texas Parks and Wildlife, Inland fisheries Division, San Marcos.
• The Nature Conservancy. Element Stewardship Abstracts. Housed at iMap Invasives. http://www.imapinvasives.org/GIST/ESA/index.html
• Tropical forages. http://www.tropicalforages.info/index.htm.
• University of Connecticut. Plant Database. http://www.hort.uconn.edu/plants/index.html.
• Virginia Tech Weed Identification Guide. Johnsongrass: Sorghum halepense. http://www.ppws.vt.edu/ scott/weed_id/sorha.htm
• Warner, P.J., C. C. Bossard, M.L. Brooks, J. M. DiTomaso, J. A. Hall, A. M. Howald, D. W. Johnson, J. M. Randall, C. L. Roye, and A. E. Stanton. 2003. Criteria for Categorizing Invasive Non-native Plantsthat Threaten Wildlands. California Exotic Pest Plant Council and Southwest Vegetation Management Association.
• White, J.A. 2007. Recommended Protection Measures for Pesticide Applications in Region 2 of the U.S. fish and Wildlife Service. U.S. fish and Wildlife Service, environmental Contaminants Program, Region 2.
• Yao, S. 2010. Scientists release Biocontrol for water hyacinth. United States Department of Agriculture, Agriculture Research Service.