Forbs, vines
High
Moderate ($500–$1000)
Low/no risk
Moderate risk
Low/no risk
Low/no
Overview
Bladed hand tools encompass a variety of implements with sharpened edges for cutting, including: machetes, sharpened hoes, sling blades, sharpened shovels, double bladed weed cutters, serrated sickles, scythes, brush hooks, hatchets, and axes. They are all used to cut vegetation above the ground.
The selectivity of a bladed hand tool varies with the type of tool being used and the skill of the user. A skilled worker, for instance, can cut weeds around natives with a machete or serrated sickle without harming natives or themselves.
Bladed hand tools, though very effective at cutting vegetation, can be hazardous to use without proper safety training. The heavier the blade and shorter the handle, the greater the risk of cutting to the operator. When workers use any bladed hand tool, they should wear sturdy shoes, long pants, and work gloves to reduce risk of injury.
The general philosophy of using cutting tools for invasive weed control comes from the understanding that plants get energy from photosynthesis. Repeated removal of aboveground biomass can eventually kill the plant by starving the roots of carbohydrates. Under the right conditions and with the right timing, cutting with a bladed hand tool can also limit the reproduction of invasive plants. With persistence, this technique can be used to eradicate small stands of certain weeds. It can stop the expansion of some nonnatives along the edge of an infestation. With the exception of the brush hook, hatchet, and axe, bladed hand tools are typically used to cut fleshy, herbaceous vegetation. Woody vegetation can be cleared using a brush hook, hatchet, or axe (e.g., for fuels management), but these tools are typically not used to permanently remove or control plants. See the BMP for pruners, loppers, and saws for guidance on control of woody plants using repeated cutting.
Cutting with bladed hand tools is a technique that is especially valuable when soil disturbance should be minimized, either because of a weed seed bank that would otherwise be triggered to germinate, or because of sensitive biological or cultural resources. It is considered a long-term management technique that requires persistence over a number of seasons and trained, skilled workers to be effective. Cutting must be timed properly and occur multiple times a year for most kinds of plants to effectively limit reproduction and spread.
Bladed hand tools are often used as part of an integrated management program to target small patches of weeds. Their use, while effective, can be quite labor intensive, and for dense patches of weeds covering larger areas there are often better tools to choose (see String Trimmer and Brush Cutter BMP). With that being said, they are lightweight, easy to use, and can be an ideal choice for weed control for smaller and more remote areas.
How to Use
Bladed hand tools can be used at any time of year for cutting back non-woody species, but their use must be carefully timed if meant to effectively control a stand of weeds. Cutting should occur before a plant goes to seed and, for most species, multiple visits per year will be needed to eliminate seed production. If plants have already begun to set seed, cut material may need to be bagged and taken off site to ensure that seeds are not spread on site. Plan on returning to the same site for multiple years to target regrowth and new plants recruited from the seed bank. In sites that have remnant native vegetation, careful removal of nonnatives is often enough to allow the natives to return to dominate the site.
Annual plants are chemically triggered to die once they reproduce, so a carefully timed single cut low to the ground late in their development--at bud stage or early flowering--can stop reproduction of individual plants and kill them prematurely under the right conditions. Cut as low as possible to the ground to reduce and delay plant regrowth. Multiple cuts per growing season may be needed to ensure seeds are not set, with more cuts per season being required in areas with higher precipitation. The number of rounds of cutting for an annual like black mustard can vary widely, from only requiring one basal cut at flowering to needing up to four cuts in a season, depending on rainfall, timing of cutting, and regrowth after the initial cut.
Perennial plants will require multiple treatment visits per season to stop reproduction and control plants, depending on plant type, timing of cutting and timing and amount of annual precipitation. Rainfall is highly variable in semiarid regions of California and throughout the state among different habitat types. Some sites may need to be visited monthly or even weekly to ensure seed set does not occur. Root systems of rhizomatous perennial vegetation may not be effectively controlled through cutting.
Although cutting technique should be customized to each type of bladed hand tool and type of vegetation being cut, there are basic rules of thumb to follow to increase efficacy and reduce worker risk. Cut as low to the ground as possible to eliminate all green tissue above ground, unless only seed heads are being targeted. Never swing a bladed hand tool in a manner that could inadvertently come in contact with your body or those of someone near you.
Machetes can be used to cut many types of vegetation by swinging the blade close to ground level to sever stems. Consider holding a stout tool or forked stick in your free hand to push vegetation away and expose stalks for cutting lower to the ground. Machetes that are toothed on one side can be useful to help grab the vegetation prior to cutting and to pull it out of the way after cutting. Modified hoes with square edges sharpened and tips cut off (see photo) work well for removing photosynthetic stems at ground level. These implements are useful for treating lower-stature vegetation without bending over. A double-edged weed cutter can be used to cut erect, fleshy vegetation (e.g., milk thistle and Italian thistle) and is operated by swinging the tool back and forth, keeping the blade low and level to the ground.
Serrated sickles can be used to cut back fleshy vegetation, vines, and even small twigs of shrubs. Pull the sickle towards you and rotate it around the base of the plant in order to fully utilize the serrated edge. Use serrated sickles after annual broad-leaf weeds become too large for hand pulling to minimize soil disturbance. Serrated sickles can also be used to cut grasses.
A sling blade or sharpened shovel can be used to cut fleshy vegetation, such as artichoke thistle (Cynara cardunculus). Although these tools work well for severing larger plants at ground level, sling blades in particular are heavy, less versatile, and not well-suited for small plants. They are sharp and heavy and can cause injury to the user if used improperly. The hooked tip to a sling blade is helpful for removing cut vegetation.
Scythes are useful for controlling annual grasses and certain fleshy broadleaf plants. Experienced users have found the Eastern European pattern scythe, designed for cutting grass crops, is more effective than the British Seymour-style scythe that is more commonly sold in the United States. Scythes should be used in a sweeping motion near the soil surface, where higher cuts may not effectively cut the target vegetation. This tool can be difficult to use effectively in areas of uneven rocky terrain and requires training to use. Maintain a 10’ spacing between workers for safety.
Machetes and sling blades are particularly dangerous to use for untrained workers. Workers should cut only in front of their bodies. Never reach out to one side or the other to make quick clean-up cuts in such a way that the blade is moving toward your legs and (in the case of machetes) your hand. Never grab a fistful of brush with one hand and swing the machete with the other.
Cutting tools must be sharpened regularly. Before sharpening, use a hand block sander (like Sandflex™) to clean the blade with a circular motion, removing “gunk”). Sharpening hand tools is best completed before going out to the field using a vice and a file in the shop. In the field, use a diamond hone – first the coarser (blue) side with a rotating motion on both sides of blade and then the finer (red) side to finish off.
As an example of the effectiveness of bladed hand tools consider the experience at Audubon Starr Ranch (in Orange County, CA) controlling artichoke thistle, a large, tap-rooted perennial. Cutting was found to be effective over two years if repeated cutting occurs from November through end of May at 3-week intervals in Year 1 and 4-8 week intervals in Year 2. Regrowth from the seed bank is controlled thereafter by cutting at 4-8 week intervals, depending on site conditions. First year cutting uses brush cutters with heavy string. Subsequent cutting uses modified cutting hoes. (A sharpened angled hoe can also be used to cut off rosettes of bull thistle, ox tongue, and sow thistle. Other practitioners use modified shovels in a similar manner by bending and rewelding the shovel like a hoe and sharpening the cutting edges. Some similar tools are now commercially available.)Experiments on timing for cutting leafy rosettes showed no significant difference between initiation of cutting at first resprouting after rains versus initiating cutting at bolting stage.
Non-Chemical Weed Control: Bladed Hand Tools, Sandy DeSimone from Cal-IPC on Vimeo.
Special Tips
Optimal timing and frequency of cutting may not always be known for a specific species, site, or environment. Experiment with cutting frequency and monitor regrowth over multiple seasons to optimize your cutting schedule for reducing or preventing seed set. Work sites can be numbered and then scheduled on a work calendar to keep visits regular. Keep in mind that changes in rainfall patterns will affect timing and frequency of cutting needed to be effective.
Bladed hand tools often work best for cutting plants once they have bolted and when they are “top-heavy” so they easily fall aside upon cutting. Know when target species bolt and bloom to optimally time cutting, especially if you cannot maintain a repeated cutting schedule.
Serrated sickles can be modified to be long-handled tools by attaching a pole (e.g., PVC pipe) to them to get into areas with thorny vegetation or poison oak.
Consider marking tool handles of your tools with florescent paint to avoid losing them in the field. Weathered wooden handles can be treated with linseed oil to rejuvenate the wood and reduce the risk of splinters.
Optimal Conditions for Use
Even terrain is optimal for cutting at ground level. Areas need enough room to swing the bladed hand tool. Time cutting before a dry period to help reduce regrowth (rain stimulates regrowth).
Caveats
Multiple and regular cuts are required for multiple years in order for cutting with bladed hand tools to be effective as a weed control tool. This repeated cutting is expensive, time consuming, and hard work. Patience, consistency, and persistence are necessary for using bladed hand tools effectively as a management tool.
If weeds are already flowering when cut, flower heads may still be able to set viable seed and therefore may need to be bagged. Cutting plants that have already gone to seed may increase seed shatter and increase the distribution of these invasive plants. For any species, understanding the soil seed bank dynamics is critical for planning a long-term control strategy. Like any management approach, allowing seeds to be produced one year can undo years of seed suppression.
Invasive grasses may not be the best species on which to use bladed hand tools for control. Grass meristems (growth points) are typically low to the ground, below the cut line. Suppression of grass growth and seed production can be achieved through cutting, but species elimination and control will often fall short.
Perennial rhizomatous species, such as Canada thistle or perennial pepperweed are not effectively controlled by cutting with hand tools, regardless of precipitation. These species may be cut at the bud stage, multiple times per year, for multiple years and still not kill the root system (above ground biomass and seed production will be suppressed but not controlled).
Potential Hazards to Humans, Environment, and Cultural Resources
Human safety: Moderate risk. Bladed hand tools can cause injury from cutting if used improperly. Machetes, in particular, should only be used with extensive training and are not recommended for volunteers. Any sharp implement that will easily cut through a thick plant has the potential to cut the user or someone else. Some implements like a sharp shovel inherently have less risk than other implements like a serrated sickle or a machete. It is important to use these tools in a manner such that the blade does not move towards the user or others in the vicinity. Wearing boots, gloves, pants, and long sleeves will help protect the user. Caution must be taken when cutting species that have the potential to be toxic (such as myrtle spurge or poison oak) so the user does not expose themselves to toxic saps or oils).
Cultural resources. Low risk. Because bladed hand tools cut above-ground plant material, they are not likely to damage cultural resources at or below ground level.
Habitat. Low risk. Bladed hand tools are typically used for precision work and therefore do typically pose a threat to habitat. If they are used on larger patches of invasive plants the impact to habitat increases.
Sensitive species. Low-moderate risk. Check sites before cutting to avoid disturbing nesting birds. No weed control should be done when ground nesting birds are breeding on site
Erosion. Low risk. Because bladed hand tools cut above-ground plant material and keep roots intact, risk of erosion is minimal.
Consider Combining with the Following Non-Chemical Methods
In larger areas which have been treated with a mower or a string trimmer, bladed hand tools can be good choices for follow-up to treat regrowth or plants that were missed. Sharpened hoes can be good follow-up for perennial, tap rooted, rosette species like artichoke thistle after initial mowing.
Don’t Use This Technique When/For
Do not use this technique to target rhizomatous perennial species. These plants will continue to send up shoots from their extensive root systems, even if multiple cuts are made. Cutting these species once can stimulate new growth from lateral roots, increasing patch size and density.
References
DiTomaso, J.M., G.B. Kyser et al. 2013. Weed Control in Natural Areas in the Western United States. Weed Research and Information Center, University of California. 544 pp.
Ross, M. 2019. Tips for using a machete.https://www2.fiskars.com/Ideas-and-How-Tos/Gardening-and-Yard-Care/Landscaping/How-to-use-a-Machete
Vandeman, M.J. 2017. How (and Why) to do Habitat Restoration. How (and Why) to Do Habitat Restoration.https://mjvande.info/habitat_restoration.htm
Authors and Credit
Lead Author: Sandy DeSimone, Science Director, Audubon Starr Ranch
Co-authors:
Tom Getts, University of California Extension Weed
Specialist, UC ANR
Shani Pynn, Senior Plant Restoration Ecologist, Riverside
Corona Resource Conservation District
Collin Raff, Restoration Manager, Irvine Ranch Conservancy
Additional Contributors:
Jutta Burger, Science Program
Director, California Invasive Plant Council
John Kenny (volunteer)
Ken Moore, Wildlands Restoration Team
Dave Wilson (volunteer), Irvine Ranch Conservancy
Efficacies
| Rating | |||
|---|---|---|---|
| Plant | Flowering Period | ||
| Winter | Good | ||
| Spring | Good | ||
| Summer | Good | ||
| Fall | Good | ||
| Multiple Seasons | Fair | ||
| None | Poor | ||
| Plant | Germination | ||
| Winter | Good | ||
| Winter / Spring | Good | ||
| Spring / Summer | Good | ||
| Opportunistic | Good | ||
| Plant | Palatability | ||
| Yes | No Information | ||
| No | No Information | ||
| Partial | No Information | ||
| Plant | Plant Growth Form | ||
| Grass | Fair | ||
| Forb | Good | ||
| Shrub | Poor | ||
| Tree | Ineffective | ||
| Vine | Fair | ||
| Plant | Plant Type | ||
| Annual | Good | ||
| Biennial | Fair | ||
| Perennial | Fair | ||
| Plant | Propagule Production | ||
| Low (<1000/square meter) | Good | ||
| Moderate (1000–10,000/square meter) | Good | ||
| High (>10,000/square meter) | Good | ||
| Plant | Rate of Spread | ||
| High (doubling in <10 year) | Fair | ||
| Moderate (50–75% increase in 10 years) | Good | ||
| Slow Rate (25% increase in 10 years) | Good | ||
| Plant | Resprouting / Regenerative Capacity | ||
| Low | Good | ||
| Moderate | Fair | ||
| High | Poor | ||
| None | Excellent | ||
| Plant | Seed Life | ||
| Short (≤3 years) | Good | ||
| Moderate (4–10 years) | Good | ||
| Long (>10 years) | Fair | ||
| Plant | Type of Reproduction | ||
| Seed | Good | ||
| Vegetative | Poor | ||
| Seed & Vegetative | Fair | ||
| Plant | Type of Vegetative Reproduction | ||
| Rhizome / Stolon / Stem | Poor | ||
| Bulb / Corm / Tuber | Poor | ||
| Root sprout / Sucker / Crown sprout | Fair | ||
| Site | Existing Desirable Plant Cover | ||
| <10% | Good | ||
| 10–25% | Good | ||
| 26–50% | Good | ||
| 51–75% | Good | ||
| >75% | Good | ||
| Site | Ground Condition | ||
| Muddy | Fair | ||
| Smooth | Excellent | ||
| Cobbly | Good | ||
| Rocky | Fair | ||
| Site | Habitat | ||
| Marsh / Wetland | Fair | ||
| Riparian | Good | ||
| Grassland | Excellent | ||
| Shrubland | Excellent | ||
| Woodland / Forest | Good | ||
| Site | Level of Tolerable Disturbance | ||
| Low | Good | ||
| Medium | Good | ||
| High | Good | ||
| Site | Slope | ||
| Flat | Excellent | ||
| Moderate (10–40%) | Excellent | ||
| Steep (>40%) | Good | ||
| Site | Target Area | ||
| <40 square feet | Excellent | ||
| 0.001–0.01 acre | Excellent | ||
| 0.02–0.1 acre | Excellent | ||
| 0.2–1 acre | Good | ||
| 2–10 acres | Good | ||
| 11–50 acres | Poor | ||
| 51–100 acres | Poor | ||
| >100 acres | Poor | ||
| Site | Targeted Invasive Plant Cover | ||
| <1% | Excellent | ||
| 1–10% | Excellent | ||
| 11–25% | Excellent | ||
| 26–50% | Good | ||
| 51–75% | Fair | ||
| >75% | Fair | ||
| Site | Vehicle Accessibility | ||
| Roadside | Good | ||
| <100 feet from road | Good | ||
| 100–1000 feet from road | Good | ||
| >1000 feet from road | Good | ||
