Control of Buckthorn with Hogs, Cutting Feed Costs with Food Waste

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2010: $5,979.08
Projected End Date: 12/31/2012
Region: North Central
State: Minnesota
Project Coordinator:
Nancy Lunzer
Farm / Ranch

Annual Reports


  • Agronomic: corn, oats, potatoes, soybeans, grass (misc. perennial), hay
  • Fruits: melons, apples, apricots, avocados, bananas, berries (other), berries (blueberries), berries (cranberries), cherries, figs, citrus, grapes, olives, peaches, pears, pineapples, plums, quinces, berries (strawberries)
  • Nuts: almonds, pistachios, walnuts
  • Vegetables: sweet potatoes, artichokes, asparagus, beans, beets, broccoli, cabbages, carrots, cauliflower, celery, cucurbits, eggplant, garlic, greens (leafy), leeks, onions, parsnips, peas (culinary), peppers, radishes (culinary), rutabagas, sweet corn, tomatoes, turnips, brussel sprouts
  • Additional Plants: native plants, trees
  • Animals: poultry, swine, sheep
  • Miscellaneous: mushrooms


  • Animal Production: feed/forage, housing, free-range, feed rations, grazing management, manure management, grazing - multispecies, pasture renovation, preventive practices, grazing - rotational
  • Crop Production: food product quality/safety
  • Education and Training: farmer to farmer, on-farm/ranch research, workshop
  • Farm Business Management: budgets/cost and returns, feasibility study
  • Natural Resources/Environment: biodiversity, habitat enhancement, wildlife
  • Pest Management: competition, eradication, physical control
  • Soil Management: soil analysis, composting
  • Sustainable Communities: local and regional food systems, community services, sustainability measures

    Proposal summary:

    Buckthorn is an exotic invasive species which forms an impenetrable understory that causes long-term decline of a forest by out competing native tree seedlings and woodland plants. Buckthorn was originally introduced by European settlers who liked the fast growth and thick hedges it produces. Currently, Buckthorn infestation is a major ecological problem in Minnesota forested lands. It spreads quickly, mainly by seeds which are ingested by birds. The seeds cause a laxative effect and are spread as the birds defecate in the environment. Because of the laxative effect they have almost no nutritive value to the birds and the seeds remain viable in the soil for 4-6 years.

    The sale of Buckthorn was halted in the 1930's when it was discovered to be a host to oat crown rot, a fungal disease of oat crops. In 2001, it was discovered that Buckthorn is also a winter host to the soybean aphid, a new insect pest introduced in the US.

    The target area of Buckthorn consists of ten acres and has two main soil types: Brennyville Complex and Brennyville Wet Cebana. These soils are heavy, wet, mostly clay and very rocky. The area is level with slopes of 1-6% with a high water table. It has a predominately Buckthorn understory and very few other woodland plants. The canopy is older Aspens and it has a very light secondary canopy of Sugar Maples and Oaks.

    Traditional methods for controlling Buckthorn include; herbicide treatment, clear cutting followed by herbicide treatment, and hand pulling or wrenching, which needs to be repeated annually. Costs for controlling Buckthorn in our area typically run $170 to $250/acre for the initial mechanical removal of a moderate Buckthorn understory with an additional estimated cost of $150/acre herbicide treatment (if landowner applies it) and $300 if contracted. It will need to be treated annually for at least 4 years until the seed bank is depleted. Controlled burning is sometimes used but mostly in prairie and savannah areas.

    These traditional methods of controlling Buckthorn are not conducive to this project site. This area is home to 7 species of reptiles and amphibians, 10 species of mammals and 47 species of birds. The entire area of Buckthorn drains into the wetlands during spring snow melt and run-off during heavy rains. Clear-cutting the area is undesirable because the mature trees provide a windbreak to the homestead and livestock areas. It is my goal to get rid of the Buckthorn without destroying the windbreak and without leaching herbicide and silt into area wetlands.

    The summer of 2010 I tried a small pilot project. The Pilot project employed two feeder pigs to clear a small area of Buckthorn. The hogs worked the ground around the large trees and boulders without disturbing deep rooted tree species and without compacting the soil. Berkshire hogs are a breed known for their foraging ability. They are black and less likely to sunburn than white breeds. The hogs worked day and night rooting up vegetation in search of grubs, earthworms, roots, mushrooms, acorns, and butternuts. They turned the top 6-8 inches of soil, digging out stumps, rocks and roots; gleaning anything edible from the forest floor. They trampled the downed vegetation breaking it up under foot and driving it into the soil.

    Once the Buckthorn was hogged-off, the hogs were removed and the area was planted to shade tolerant grasses. Varieties of grass that do well in shade are a mix of Kentucky Blue Grass, Creeping Red Fescue, Predator Hard Fescue, and Cascade Chewings Fescue.

    Hogs on pasture are healthier than confinement hogs and the piglets require less processing. Pastured piglets get all of the iron they need from the soil, making supplemental iron shots unnecessary.

    Pastured hogs don't exhibit tail biting behaviors, so docking tails is unnecessary. Pastured hogs spread manure naturally so odor and ground water issues are avoided. Pasture pork has less environmental impact than confinement raised pork.

    Pastured hogs require much less capital investment in buildings and equipment than hogs raised in large confinement buildings. Pastured hogs use small houses for shelter and rarely defecate in their bedding; manure is spread on the pasture as they graze. To avoid the build-up of parasites; the hogs; their housing and their water is moved to fresh soil every few weeks. The tilled soil and the rich nutrients of the hogs' manure, as well as the high water table of this area makes an ideal seed bed for the fast germination of grasses, without the use of tillage, seeding and irrigation equipment reducing input costs.

    Once the Buckthorn is hogged off and shade tolerant grasses have been established, it will be necessary to deplete the viable Buckthorn seed bank by follow up grazing using intensive rotational grazing techniques. Grazing with sheep during subsequent years will keep pressure on returning Buckthorn seedlings; Hair sheep are browsers as well as grazers and will forage on both grass and broadleaf plants.

    Buckthorn seeds remain viable in the soil for 4-5 years, so a multi-year plan is important for success.

    Feeding hogs can be expensive. Most hog rations consist of ground corn and soybean meal. But hogs can eat a wide variety of foods. Pasture hogs can get 50 percent of their rations from good pasture and woodland forages. The other 50 percent of their ration can be provided through alternative sources like food waste from grocery stores.

    It is estimated that 40 percent of the food produced in America is wasted. Grocery stores throw out billions of dollars of almost fresh produce, bakery goods, and dairy products every day. All of this waste is hauled at great cost to landfills. Grocery stores are reluctant to donate out-of-date food for human consumption because of food safety issues. But the waste of good food is unconscionable when using it to raise hogs is possible. The pilot project included the feeding of food waste. The hogs enjoyed fresh fruit and vegetables, breads and other bakery products and dairy products like milk, yogurt, and ice cream. I will expand the food waste project to feed six hogs.

    Project Requirements:
    The project will require permanent fencing on the perimeter of the ten acre site to contain the hogs and sheep, as well as keep out predators. Temporary interior fences of electric weave wire will be used to section off smaller areas to be intensively grazed by 6 Berkshire feeder pigs.

    As the Buckthorn is rooted up, the pigs will be moved to new areas of Buckthorn forest.

    Fecal samples will supply information on parasite populations in hogs and sheep.

    The pigs will be provided with farrowing huts for shelter, because they are easy to move with two people, and straw will be used for bedding. Sheep will use the huts the following year.

    Water will be provided using water hoses and a livestock tank.

    Hog rations of corn and soybean meal will be supplemented by pasture and woodland forage and food waste from local grocery stores. I will provide food containers to the grocery store to collect the food. The food will be picked up and brought to the farm where it will be sorted, unpackaged, and the packaging will be sorted for recycling.

    Food not fed that day will be kept fresh by refrigeration or freezing. Food not fresh enough to be fed will be composted. Food containers will be pressure washed and disinfected and exchanged at the store for full containers.

    Shade tolerant varieties of grass species will be broadcast onto hog tilled soil to establish vegetation, control erosion, and provide competition to returning Buckthorn. Soil tests will determine soil deficiencies.

    The second year will be followed by intensive rotational grazing techniques to keep pressure on returning Buckthorn. Tony Miller will help monitor control methods and offer suggestions as the project progresses to return the forest to a healthy condition.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.