Shrubs, trees
Indiscriminate
High (>$5000/gross)
Low risk
Moderate risk
High risk
High (erosion, sensitive plants, wildlife, habitat)
Overview
Large equipment consists of machinery such as bulldozers and backhoes. Under the right conditions, with appropriate permissions, and with a skilled operator, whole plant removal with large equipment is an effective method for not only removing entire plants but often the surrounding seed bank as well. This method can be effective on virtually all plant types and forms, regardless of phenology, flowering, or germination. Digging with large equipment is generally not suitable for areas with intact surrounding desirable vegetation unless this vegetation can be easily re-established or protected. Soil compaction that results from using heavy equipment can negatively affect revegetation efforts if not addressed. Use of heavy equipment is usually not cost effective in situations with low invasive plant cover. It is limited to stable, accessible terrain or areas within reach of equipment situated on adjacent stable ground.
Annual plants and some shallow-rooted perennial plants can be removed with their roots by scraping the soil, which removes the top inch to several inches of soil and much of the weed seed bank. Vines, deep-rooted perennial forbs and grasses, shrubs and trees more often require deeper and more targeted excavation. While effective, a thorough job usually results in significant soil and habitat disturbance. Also, equipment rental and operation are expensive. Therefore, this technique is typically reserved for extreme conditions under which other techniques will not work. For example, large equipment is highly efficient for large areas that need full restoration or re-landscaping, as in fields of pampas grass or other large, high-density, contiguous infestations where killing and removal of biomass is the essential first step to re-establishing desirable vegetation.
Because of the intensity of soil and habitat impact, permits are often required when digging. Underground infrastructure (such as gas, water and electric utilities), soil stability, cultural resources, and wildlife can all be impacted.
This technique can be used for eradication but must be followed by maintenance to revegetate a site and ensure its seed bank is fully depleted.
How to Use
Heavy equipment comes in many shapes and sizes and can perform a wide variety of work. This technique of whole plant removal on a large scale can produce a ‘clean slate,’ removing all aboveground and belowground biomass. However, this outcome is rarely permissible or desirable unless a site is a future construction site or very intensive active restoration is planned as a follow-up.
Equipment can be used to pull out plants and their roots, dig out or scrape off roots, scrape herbaceous plants, and remove top soil with its seed bank. Equipment that can be used for scraping and digging include: backhoes, skid-steer loaders (Bobcat™), and dozers. Suitable attachments for scraping include buckets, box scrapers, and rippers for loosening compacted soil. Attachments typically used for digging include either a bucket or a reticulating bucket. Any operator of excavation or digging equipment should be properly trained to use the equipment safely and effectively. Scraping and digging should be followed by regrading and replanting or seeding.
Scraping. Scraping can remove above ground plant and shallow roots along with seeds in top layer of soil, a minimum of 1 inch. Deep scrapes can remove deeper roots, all aboveground material and soil seed banks.
In certain circumstances, the removal of nutrient-rich soil by scraping can benefit the establishment of native grasses, known to be more competitive than annual exotic grasses in poor soil conditions. This technique has been utilized effectively on serpentine soils at small scales where large equipment has not damaged surrounding areas.
Uprooting. Large plants like pampas grass and various shrubs and small trees can be pulled out with an articulating bucket on a front loader, plucked out with backhoe, dug out with a bucket attached to a skid-steer or backhoe claw, or pulled out with a chain attached to a tractor or truck.
Raking. Chain harrows pulled behind trucks/tractors can be used to perform a shallow till and rake to remove low-growing herbaceous plants and their roots. This technique leaves soil prepped for seeding or follow-up applications. (See also Mechanized Tillage.)
The greatest constraints on the use of this technique are the amount of collateral damage, the expense, the dependence on suitable topography, and the availability of appropriate equipment and skilled operators. Proper use of heavy equipment requires trained operators, maintenance, and associated personnel for fire suppression and public safety.
Special Tips
After full plant removal using large equipment, competitive planting should be used as a follow-up. All sites should be revisited to either dig out, clip, or manually remove seedlings and any remaining resprouts that have been left behind. Make sure to secure all necessary permits to complete work and implement best management practices to reduce erosion and negative impacts to wildlife.
Optimal Conditions for Use
Large equipment is most suitable for flat easily accessible sites with high invasive plant cover.
Caveats
- Wet conditions may make terrain too unstable to support equipment.
- Wet conditions increase soil compaction from equipment.
- The optics of this technique can create public concern. Use explanatory signage.
- Equipment is expensive, requires a trained operator, and can be difficult to get.
- This technique is carbon-intensive and creates local pollution from burning fossil fuels.
- Moving large quantities of soil requires best practices for reuse or disposal.
- Moving soil brings risk of moving Phytophthora soil-borne pathogens. It is important that equipment arrives on-site free of dirt and vegetative debris, and that equipment is cleaned before it moves to the next project. See http://phytosphere.com/ for more information.
- Off-road equipment may damage more habitat than it helps to protect by removing weeds depending on the site.
- Permitting will probably be needed.
- Heavy soil disturbance may create erosion.
- Heavy equipment use can result in fuel and oil leaks or spills. Spill kits should be on site and available for use.
Potential Hazards to Humans, Environment, and Cultural Resources
Human safety. Moderate risk. Operators and nearby personnel can experience fatigue, hearing damage, repetitive stress injuries, inhalation of exhaust and dust, etc. Equipment can also roll over on uneven terrain. Proper training and Personal Protective Equipment (PPE) are essential.
Cultural resources. High risk. Heavy equipment can damage cultural resources that are buried in soil or on the surface. Field surveys should be performed by a qualified professional.
Sensitive species. High risk. Any ground-dwelling insects, birds, amphibians and small mammals can all be harmed by heavy equipment. Work sites should be cleared by a qualified biologist.
Habitat. High risk. Removal of nesting habitat, structure and cover for many wildlife species is likely with excavation. This method is very destructive and should only be used when the benefits outweigh these impacts.
Erosion. High risk. Due to significant soil disturbance, erosion potential is high, especially when work is performed during the rainy season or on slopes. This risk can be mitigated by implementing erosion prevention measures.
Fire. High risk. Heavy equipment can start fires if operated in fine dry fuels. Assess the fuel conditions on site and consult fire weather restrictions in your area. This risk can be mitigated by having fire suppression equipment on site while working.
Consider Combining with the Following Non-Chemical Methods
Competitive planting is recommended as a follow-up technique in any area with substantial soil disturbance and low chance for natural regeneration. This technique can also be paired with manual removal to control resprouts or seedlings.
Don’t Use This Technique When/For
- Wet, steep or remote conditions.
- When sensitive resources are present.
- Without trained professional operators.
Authors and Credit
Lead Author: Pamela Beitz, Integrated Pest Management Specialist, East Bay Regional Parks District
Co-authors:
Ross Mitchell, AWP Supervisor, East Bay Regional Parks District
Additional Contributors:
Bruce Adams, Park Ranger, East Bay Regional Parks District
Suggested Citation:
Beitz, P. and R. Mitchell. Whole Plant Removal with Large Equipment. Weed Control User Tool (WeedCUT) – Methods for Managing Weeds in Wildlands. weedcut.ipm.ucanr.edu. California Invasive Plant Council (Cal-IPC) and University of California Statewide Integrated Pest Management Program (UC IPM). Accessed [date].
Efficacies
| Rating | |||
|---|---|---|---|
| Plant | Flowering Period | ||
| Winter | No Information | ||
| Spring | No Information | ||
| Summer | No Information | ||
| Fall | No Information | ||
| Multiple Seasons | No Information | ||
| None | No Information | ||
| Plant | Germination | ||
| Winter | No Information | ||
| Winter / Spring | No Information | ||
| Spring / Summer | No Information | ||
| Opportunistic | No Information | ||
| Plant | Palatability | ||
| Yes | No Information | ||
| No | No Information | ||
| Partial | No Information | ||
| Plant | Plant Growth Form | ||
| Grass | Excellent | ||
| Forb | Excellent | ||
| Shrub | Good | ||
| Tree | Poor | ||
| Vine | Good | ||
| Plant | Plant Type | ||
| Annual | Excellent | ||
| Biennial | Good | ||
| Perennial | Fair | ||
| Plant | Propagule Production | ||
| Low (<1000/square meter) | Excellent | ||
| Moderate (1000–10,000/square meter) | Excellent | ||
| High (>10,000/square meter) | Good | ||
| Plant | Rate of Spread | ||
| High (doubling in <10 year) | Good | ||
| Moderate (50–75% increase in 10 years) | Excellent | ||
| Slow Rate (25% increase in 10 years) | Excellent | ||
| Plant | Resprouting / Regenerative Capacity | ||
| Low | Excellent | ||
| Moderate | Excellent | ||
| High | Excellent | ||
| None | Excellent | ||
| Plant | Seed Life | ||
| Short (≤3 years) | Excellent | ||
| Moderate (4–10 years) | Excellent | ||
| Long (>10 years) | Excellent | ||
| Plant | Type of Reproduction | ||
| Seed | Excellent | ||
| Vegetative | Good | ||
| Seed & Vegetative | Good | ||
| Plant | Type of Vegetative Reproduction | ||
| Rhizome / Stolon / Stem | Good | ||
| Bulb / Corm / Tuber | Good | ||
| Root sprout / Sucker / Crown sprout | Good | ||
| Site | Existing Desirable Plant Cover | ||
| <10% | Excellent | ||
| 10–25% | Poor | ||
| 26–50% | Poor | ||
| 51–75% | Poor | ||
| >75% | Poor | ||
| Site | Ground Condition | ||
| Muddy | Poor | ||
| Smooth | Excellent | ||
| Cobbly | Good | ||
| Rocky | Good | ||
| Site | Habitat | ||
| Marsh / Wetland | Poor | ||
| Riparian | Good | ||
| Grassland | Excellent | ||
| Shrubland | Excellent | ||
| Woodland / Forest | Excellent | ||
| Site | Level of Tolerable Disturbance | ||
| Low | N/A | ||
| Medium | Poor | ||
| High | Excellent | ||
| Site | Slope | ||
| Flat | Excellent | ||
| Moderate (10–40%) | Good | ||
| Steep (>40%) | Poor | ||
| Site | Target Area | ||
| <40 square feet | N/A | ||
| 0.001–0.01 acre | N/A | ||
| 0.02–0.1 acre | Excellent | ||
| 0.2–1 acre | Excellent | ||
| 2–10 acres | Excellent | ||
| 11–50 acres | Excellent | ||
| 51–100 acres | Excellent | ||
| >100 acres | Excellent | ||
| Site | Targeted Invasive Plant Cover | ||
| <1% | N/A | ||
| 1–10% | N/A | ||
| 11–25% | Excellent | ||
| 26–50% | Excellent | ||
| 51–75% | Excellent | ||
| >75% | Excellent | ||
| Site | Vehicle Accessibility | ||
| Roadside | Excellent | ||
| <100 feet from road | Excellent | ||
| 100–1000 feet from road | Good | ||
| >1000 feet from road | Poor | ||
