Park system looks to goats, fewer herbicides to fight invasive species


The Minneapolis Park and Recreation Board is considering policies, from better record keeping to using goats, to improve its invasive species control and, ultimately, to reduce its use of potentially harmful chemicals in the city’s parks.

Park staff presented March 16 a new report on the board’s use of herbicides, insectides and fungicides in the city’s park system. While commissioners on the Operations & Environment Committee moved forward with several recommendations from staff, high on the board’s list is the elimination of glyphosate, an active ingredient in herbicides like Roundup, in neighborhood parks.

“Roundup has been considered safe in the past, however, recent research raises some concerns as to whether this is true. The Operations Committee chose to err on the side of safety for residents, our employees, and environment,” said At-Large Commissioner John Erwin, who also works as a horticultural science professor at the University of Minnesota, in a Facebook post. 

Erwin also put forth a new trial run to use goats to control invasive species like buckthorn and garlic mustard. The Park Board has looked into using hoofed animals like goats and sheep for decades, including four years ago when Erwin said the cost was too high to move forward. Now, at likely a much lower cost — $2,000, down from $75,000, Erwin said — the board is considering using goats in two areas later this year. At-Large Commissioner Annie Young and District 6 Commissioner Brad Bourn have touted the effort.

Commissioners have brought up an area with buckthorn off of Wirth Parkway in Theodore Wirth Park as a potential test site. The action, which still needs full board approval, will need a variance from the City Council due to a city ordinance excluding hoofed animals, but Erwin said he’s begun working with council members.

The report also detailed the board’s recent use of herbicide.

Assistant Superintendent Justin Long told commissioners that the board has reduced its use of liquid herbicide in neighborhood and regional parks by 98 percent.

Last year, staff applied 15 gallons of liquid herbicide on 51 acres — less than 1 percent of the 6,700-acre system — Long said. That’s down from 702 gallons applied to 400 acres in 2008.

The sharp decline in liquid herbicide follows a shift to solid, granular herbicide, which went from 0 to 1,100 pounds in the same 2008-2015 timeframe.

Minneapolis residents and their contractors also applied pre-approved herbicides to more than 1,000 ash and elm trees between 2014 and 2015, usually for emerald ash borer or Dutch elm disease.

Several speakers and activists spoke at the meeting to push commissioners to ban pesticides and/or make the city’s parks organic.

While Commissioner Scott Vreeland voiced his support for reducing chemical applications, he said pesticides make sense in some cases. He pointed to the fact that the Park Board used herbicide to thwart the spread of Brazilian waterweed, an aquatic invasive species, in Powderhorn Lake in 2007.

“I am going to say there are sometimes when a pesticide application is the best ecological management tool we have,” he said.

The system’s golf courses have seen much of the board’s herbicide treatments.

Last year, staff applied 2,556 pounds of solid herbicide and 598 gallons of liquid herbicide to golf courses. While levels of liquid herbicide have been more consistent with roughly 200-500 pounds applied annually in recent years, the Park Board’s use of solid herbicide has varied. Staff have applied as little as 500 pounds to as much as nearly 15,000 pounds annually in the past few years, though two courses, Hiawatha and Meadowbrook, haven’t been fully operational since the 2014 season due to flooding.

Commissioners on the committee also directed staff to begin a set of recommendations, including establishing an integrated pest management committee to review the board’s policies regarding invasive species control.

Long is also looking to add staff, such as parkkeepers and field staff, to step up weed removal to offset further reductions in pesticide use. Staff want to establish a new record keeping system to keep track of herbicide use data, which is shared with the Minnesota Department of Agriculture.

  • Roy Austin

    Goats, a Green Vegetation Management Approach

    Why use goats?

    There have been various approaches to weed and brush control, none fully satisfactory nor efficient. Using goats is an efficient, holistic, environmentally healthy green approach to weed and brush control allowing us to restore degraded land in a shorter period of time.

    How do goats help restore natural areas?

    Using goats is based on a natural process, like bison grazing the prairie.

    Goats eat dried and fresh above-ground plant parts.

    They break plants down into digestible pieces by chewing.

    Their hoof action also breaks apart plants into smaller pieces.

    Plants decompose releasing nutrients into the soil.

    Goats also work desired seeds into soil with their hooves.

    Goats can restore large areas in a shorter time period than people.

    Why is using goats environmentally healthy?

    Grazing is an alternative to mowing, herbicides and expensive manual labor.

    Goats eat plants, eliminating debris and recycling nutrient elements.

    They maintain beneficial soil organisms.

    Goats exclude the use of heavy equipment minimizing soil disturbance and compaction.

    Goats trample dried brush, create a natural mulch and add organic matter to the soil.

    Why use goats instead of other methods?

    Goat grazing is not a replacement, but another tool in the tool box of weed control and land restoration. They can cover large areas in a shorter period of time than most manpower. One hundred goats average 1/2 acre per day.

    Goats are best used:

    a) In areas with poison oak, blackberry, and heavy brush they break off the dead biomass.

    b) In sensitive areas near waterways, rivers and lakes where chemicals are prohibited.

    c) On steep embankments difficult for people or machines.

    d) On ditches, canals, rocky and wooded areas where mowing or spraying is difficult or inadvisable.

    e) In large areas where manpower is unavailable and costly.

    f) On very degraded land where human efforts would take years.


    a) Do not bring weed seeds to the surface.

    b) Do not disturb the soil organisms.

    c) Do not extract soil nutrients. d) Manure is dry pellets, minor smell; low nitrogen aids native plant not noxious weeds.

    d) Are not a potential risk to ground water.

    Hand weeding:

    Disturbs soil bringing more weed seeds to the surface.

    Creates plant debris that goes to landfills.

    Extracts nutrients from the soil.

    Disturbs soil organisms.

    Is labor intensive and expensive.


    Uses heavy equipment that compacts soil.

    Creates air pollution, both exhaust and dust.

    Leaves stubble, does not eliminate fuel matter or break down quickly.


    May contaminate ground water.

    May kill or disturb soil organisms.

    Does not allow seeding at same time.

    May damage desired vegetation. Disliked by general public.

    May have risk to personnel.

    How will using goats work?

    We will use a small goat herd, 45 to 200 head of mostly meat breeds of goats. They are easy to handle and friendly to people. Areas are enclosed by electric fence panels and protected with a livestock protection dog.

    In the spring, goats are used to:

    Remove top growth, eat dried brush from previous year and early cool season weeds that either over wintered or recently emerge.

    Work in desired seeds with their hooves while they graze.

    Once an area is clean, the goats are moved to the next area and the process is repeated. Placing the goats in strategic areas and managing their time in the area are key factors.

    In summer or fall the goats feed on emerging annuals and perennials:

    Managing their time to feed on the perennials minimizes food reserves in the unwanted plants and prevents plants from going to seed.

    Continuous grazing stresses the plants.

    Reseeding at this time allows desired vegetation in late summer to compete.

    In Fall and Winter the goats browse heavy brush areas reducing fuel load:

    1) Browse is faster and limbing is faster and less expensive. 2) Burning of slash can occur.

    How do we keep goats and people safe?

    Safety is critical to the success of this program. The following condition will be put in place

    1) The herder remains within contact 24/7.

    2) Goats are enclosed in portable electric fences with livestock protection dog inside the fence.

    3) Direct contact with Home Owners, Animal Control, Local Police, and the goat contractor.

    4) Signage placed around project area to inform the public.

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