JOURNAL OF PESTICIDE REFORM/ SPRING 2003 • VOL. 23, NO. 1

● ALTERNATIVES NONCHEMICAL METHODS FOR REMOVING UNWANTED BLACKBERRY PLANTS 2 BY CAROLINE COX in the northeast U.S. It thrives in dis- stock once the berry plants are re- turbed moist areas and at all eleva- moved is often critical. tions up to 5,000 feet.3 Blackberry removal techniques are Blackberry branches, called canes, site specific. What works well in one Many Northwesterners have are known for their stout thorns. Canes site might not be compatible or effec- conflicting attitudes about wild black- are biennial, producing lateral branches tive at a different site. Choose a tech- berries. A handful of ripe berries or a which bear fruit in their second year.2 nique that fits in with your goals for piece of fresh blackberry pie is a Himalayan blackberries are robust. the site after the blackberries are gone. scrumptious treat. On the other hand, They can be 10 feet tall and their canes it’s easy to hate the brambles that take can grow as much as 20 feet in a Don’t Get Discouraged! over a back fence or a creek bed. season. Trailing canes can root where Many of the characteristics of the If you decide to get rid of unwanted they contact the soil, producing “dense, Himalayan blackberry make this plant blackberries, you’ll be faced with a impenetrable thickets.”2 difficult to remove. Don’t get discour- resilient and thorny plant. It’s not true At the base of a blackberry cane is aged when you tackle a blackberry that removal of these plants “must rely an irregularly shaped crown. Roots removal project without herbicides. on foliage-applied herbicide treat- extend from this crown, and have been Remember that, according to the Uni- ments.”1 With a little persistence you recorded up to 30 feet long!4 versity of California, “blackberry plants can remove unwanted blackberries Blackberry seeds are transported by usually regrow following herbicide ap- without using chemical poisons. birds and mammals that eat the fruit. plication.”1 All techniques for remov- Seeds can remain viable in the soil for ing blackberries require persistence. Basic Biology several years.5 Plan to follow up your removal work. The common weedy blackberry in New plants can also develop from the Pacific Northwest is the Himalayan crowns and underground stems.1 Don’t Forget Disposal blackberry, Rubus discolor. Despite its There are several native blackberry All blackberry removal techniques name, it is a native of Europe. It is species in the Northwest.3 (except grazing) will leave you with dead widespread in southern British Colum- or dying plant material, most of it thorny. bia, Idaho, Washington, Oregon, and Focus on Desirable Plants Before you start, figure out how you northern California and is also common Start a blackberry removal project will cope with this material. by thinking about what plants you In an urban setting, your own com- want in the area that’s now blackber- post pile is a good solution. Alterna- Caroline Cox is JPR’s editor. ries. Planting desirable seeds or nursery tively, find out if your community

Oregon State University Dept. of Horticulture

Blackberries’ ability to resprout from crowns and roots, their abundant seed production, and their thorns make them a difficult plant to manage.

NORTHWEST COALITION FOR ALTERNATIVES TO PESTICIDES/NCAP 10 P. O. BOX 1393, EUGENE, OREGON 97440 / (541)344-5044 JOURNAL OF PESTICIDE REFORM/ SPRING 2003 • VOL. 23, NO. 1 offers a composting program, or if a Goat Grazing: Goats have a long local business accepts yard waste for history of use for blackberry control, composting. Then decide how to particularly in Australia and New bundle and transport your material. Zealand where they have been used In natural areas, the waste material since the 1920s. Goats eat blackber- can be piled and left to decompose. ries readily, and seem to prefer them Sprouting from these piles is rare, and over other plants.10 An economic the piles will disappear relatively analysis in Australia showed that run- quickly.6 Smaller amounts of blackberry ning goats on a blackberry-infested stems and crowns can be piled on pasture was cheaper than using her- logs, or hung from trees to dry out.6 bicides to manage the berries.11 Clearly goats are not suitable in all locations, Dress for Success but in pastures they may be an excel- Whatever removal technique you lent option. Use of goats could also choose, protect yourself from thorns. be considered in firebreaks,12 utility Leather gloves, sturdy boots, a long rights of way, and other similar sites. sleeved shirt, and jeans or other tough pants are all essential. Conclusion Many people in the Pacific North- Removal techniques Removing blackberry crowns is the key to a successful digging technique . west sympathize with the Oregon resi- Mowing and cutting: One tech- dent who reputedly said, “If we all nique for removing unwanted berries In Oregon’s Tryon Creek Natural left the valley, in three years Hima- is mowing or cutting. “Cut back the Area, enthusiastic teams of volunteers layan Blackberry would prevent us vines to ground level,” recommends led by two dedicated coordinators are from getting back in!”2 However, with Oregon State University extension successfully removing blackberries an understanding of the biology of weed scientist Jed Colquhoun, “espe- from large areas using this method. this weed and a little persistence, it is cially in the spring when the plant is Volunteers (nearby residents, employee not difficult to manage blackberries most actively growing. Cutting vines teams from a local utility, and county without pesticides. continually back will eventually kill the community service crews) provide the plant, although it may take some labor. According to coordinator Dave References time.”7 If you’re trying to turn a black- Kruse, effective digging doesn’t take 1. University of California Agriculture and Natural Resources. 2002. Wild blackberries. Pest Notes berry patch into lawn this is an ideal special techniques. He tells the volun- Publ. 7434. www.ipm.ucdavis.edu. technique. The repeated mowing that teers to dig out the crown and tells 2. Oregon State Univ. Horticulture Dept. Undated. your lawn requires, along with the them they don’t need to worry about Landscape plants: Images, identification, and in- formation. Vol. 3. http://oregonstate.edu/dept/ competition from grasses, will kill the all the little roots. Generally, they have Idplants/rudis.htm. blackberry plants. You’ll probably want found that persistence determines suc- 3. Ertter, B. 1993. Rubus. In The Jepson manual: to cut and remove the stems and leaves cess. They don’t clear areas that they Higher plants of California, ed. J.C. Hickman. Berkeley: University of California Press. of good-sized plants before you mow don’t have time to maintain. They go 4. Amor, R.L. 1974. Ecology and control of blackberry for the first time. In a small area, back about a year after the original (Rubus fruticosus L. agg.) Weed Res. 14: 231-238. loppers or weed whackers can substi- dig and remove any new plants. Typi- 5. Brinkman, K.A. 1974. Rubus L.: Blackberry, raspberry. In Seeds of woody plants in the tute for a mower. cally the number of blackberries at United States. Agriculture Handbook No. 450. Covering the soil after cutting or that point is about 1/4 of the original C.S. Schopmeyer, ed. Washington, D.C.: Forest Service, U.S. Dept. of Agriculture. Pp. 738-743. mowing can be an appropriate way to amount, but they are easier to dig be- 6. Interview with D. Kruse and P. Hamilton, Friends kill roots and crowns. A thick dark cause they don’t have large crowns. of Tryon Creek. Portland, OR. Feb. 5, 2003 material will keep light from reaching After that work is done, they find they 7. Oregon State Univ. Extension. Undated. Black- berries take time and persistence to control. new sprouts from roots or crowns so only have to check on an area about Gardening Information. www.eesc.orst.edu/ they can’t grow.8 Use this technique once every three years. They also plant agcommwebfile/garden/Fruit/blackberries.html. to transform, for example, a blackberry native conifers in newly-cleared areas, 8. Drliik, T. 1996. Stumps and brambles. Common Sense Pest Control 9:21. patch into next year’s garden. since blackberries don’t thrive in shady 9. The Nature Conservancy. 1989. Elemental stew- Digging: Digging out blackberry areas. In four years, the volunteers ardship abstract for Rubus discolor (Rubus crowns is another effective removal have taken care of most of the black- procerus), Himalayan blackberry. http:// 6 tncweeds.ucdavis.edu/esadocs.html. technique. The Nature Conservancy berries in half of the 645 acre park. 10. AgResearch Crown Research Institute. 1998. calls digging blackberries “a slow but Digging blackberries doesn’t require Goats for weed control. AgFACT No. 240. 9 www.agresearch.cri.nz/agr/pubs/agfact/pdf/ sure way of destroying” this plant. any tools other than an ordinary shovel 240goatsforweedcontrol.pdf. 6 This technique, which specifically tar- or spade. However. some diggers 11. Vere, D.T. and P.J. Holst. 1979. Using goats to gets blackberries, is useful in areas have found a claw mattock useful. The control blackberries and briars. Agricultural Ga- zette of New South Wales 90; 11-13. where preserving the neighboring veg- “claw” pulls out plants like a claw on 12. Kiester, E. 2001. Getting their goats. Smithsonian 9 etation is important. a hammer pulls out nails. Magazine (October). www.smithsonianmag.si.edu.

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