Brambles pick up viruses from other brambles: aphids carry raspberry mosaic and related viruses from wild raspberries and blackberries, and from older infected plantings, into a new one. Site a new bramble planting at least 600 feet from wild brambles, and keep it away from any bramble planting that shows virus.
Promising · suboptimal if ignored → advise
How it works
Aphid vectoring. The raspberry aphids that feed on wild and cultivated brambles pick up the viruses in one probe and carry them to the next plant they feed on, so any bramble within their flight is a source, and there is no cure once a cane is infected.
What to do about it
Plant certified virus-free stock at least 600 feet from wild brambles, dig out wild brambles nearer than that where you can, and if an older raspberry or blackberry planting in your garden shows mosaic-mottled leaves or crumbly fruit, take it out before planting new canes.
The evidence
Evidence: confirmed against 7 sources in the research-based literature.
the 7 sources
University of Maryland Extension, 'Growing Raspberries and Blackberries in a Home Garden', extension.umd.edu/resource/growing-raspberries-and-blackberries-home-garden (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Choose a planting site at least 300 feet from wild brambles, a potential source of diseases.'
UNH Extension, 'Growing Fruits: Raspberries and Other Bramble Crops', extension.unh.edu/resource/growing-fruits-raspberries-and-other-bramble-crops-fact-sheet (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Destroy all wild bramble plants within a distance of 600 feet of the site if possible, to reduce the possibility that viruses might spread to your planting.'
UMass Extension, New England Small Fruit Management Guide, 'Brambles: Viruses', ag.umass.edu/fruit/ne-small-fruit-management-guide/brambles/viruses (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Plant your raspberries away from any wild brambles which may be harboring viruses that could be spread to your plants'; 'A distance of at least 600 feet between cultivated raspberries and any wild brambles is recommended'; 'However, some raspberry varieties are resistant to aphid feeding and are thus somewhat protected.'
Penn State Extension, 'Aphids on Raspberries in Home Gardens', extension.psu.edu/aphids-on-raspberries-in-home-gardens (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Aphids can retain the virus for several hours and are very efficient at transmitting the virus from plant to plant; a single feeding probe by a single aphid suffices'; 'The maximum distance that aphids travel is unknown, but if an aphid is picked up by a stiff breeze, it can be carried for miles'; 'Eliminate virus-infected wild and cultivated raspberries'; 'Maintain 500 to 1,000 feet between new plantings and virus-infected wild and cultivated raspberries.'
UMN Extension, 'Viruses of backyard fruit', extension.umn.edu/garden-and-home/yard-and-garden/gardening-in-minnesota/yard-and-garden-problems/viruses-of-backyard-fruit (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Before starting a new fruit planting, remove or kill any wild brambles, old raspberry plants and weeds at the site.'
Iowa State Extension, 'Planting Raspberries in the Home Garden', yardandgarden.extension.iastate.edu/article/2013/04-12/raspberry.html (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'If possible, remove all wild brambles near the new raspberry planting to prevent the spread of disease.'
University of Illinois Extension, Hort Answers, 'Raspberry (Rubus idaeus and R. occidentalis)', web.extension.illinois.edu/hortanswers/plantdetail.cfm?PlantID=283&PlantTypeID=10 (fetched in-container 2026-09-02; read by the maintainer 2026-09-02): 'Plant in elevated areas away from trees and buildings, and away from wild brambles to avoid viral diseases.'
Plants this fires on
Change history
Every change to this rule is one commit. This is what the project's version history records — the date and the reason — not a summary of it.
- corpus: another rule here shared virus isolation - brambles pick up aphid-borne viruses from other brambles; keep a new planting 600 ft from wild ones (O133 step 12)
Cite this page
Milpa Gardens. "Brambles pick up viruses from other brambles: aphids carry raspberry mosaic and related viruses from wild raspberries and blackberries, and from older infected plantings, into a new one. Site a new bramble planting at least 600 feet from wild brambles, and keep it away from any bramble planting that shows virus." Evidence grade: Promising. https://milpa.garden/rules/brambles-pick-up-viruses-from-other-brambles/
A garden-planning corpus: every claim states its evidence grade and links its sources on the page. Cite it with the grade, and add the date you read it.