I have been trying to eradicate blackberry bushes from part of my yard for a decade now and they seem to be winning the war. I initially carefully dug out any bushes only to see new ones appear from what seemed like microscopic pieces of root that I missed. I weed eat them, and pull out what I can but they persist. I even covered them with black plastic for a couple years. I will not use pesticides, but am wondering if there are any other methods to try. Any help is appreciated!
Spray it with the herbicide house-hold vinegar every week or two until it dies. The vinegar won't poison the soil...
Repeated mowing/weed-whacking/weedkilling with vinegar or other form of removing the shoots & leaves at ground level will exhaust them in the end. Treating the area where they emerge as rough lawn & mowing it is what worked for me. After they were definitely gone, I turned it back to other use. The runners can travel a few meters, particularly if you have moles. Could you be re-infested from adjoining properties? Try goats :)
Rooting branch tips are predominant method of vegetative spread, from my observation & apparently yours, Ron. What I was referring, however was the plant spreading by means of underground stems(rhizomes or stolons?). They pop-up where there have been no canes previously. Perhaps this occurs more after the tops have been cut? Is this accurate & consistent with the experience of others?
OK. I went to an area actively being invaded by Rubus discolor (Himalayan Blackberry). There are 2 types of stem propagation going on. 1. The classic blackberry arching stems with "layering" tips where they touch ground. 2. There are also horizontal runners on the ground sending up shoots at some of the nodes. These horizontal stems look smaller in diameter & possibly bear smaller thorns than the arching stems that will bear the flowers & fruit. These horizontal runners are buried under debris in places. This is what happened to the ones I mentioned, I guess, including the one that was happily growing through a mole run! So, now I am clear on that point. It just makes me think that in addition to 2 variations of stem propagation, spread occurs by vegetative fragments as well as animal/bird dispersal of the prolific seeds. No wonder this plant gets around.
Still fits the pattern of what In would call branches lying on the ground and not a different type of stem that spreads beneath the soil surface, as with what is called a running bamboo. That kind of structure is what I visualized when you first said "runners".
Yes. I was interested to see the 2 different types though & clarify my information. Thank goodness they don't go in for underground stems also - in this case anyway.
They used to come over from our neighbour's property - I'm definitely not an expert but I called them "runners," too, as they grew through the ground and were white. I'd yank them out and cut them off best I could. They aren't really invasive here, though, compared to the coast, holy cow, they're everywhere there!