Hardiness Zone: 9a
Pam from Anderson, CA
One thing you need to understand about Blackberry vines is that they don't respond to control methods in the same way that many other vines do. In other words, they don't respond to "tough love." Mowing them, cutting them or burning them only encourages the growth of suckers. In fact, the more you beat blackberry vines up the stronger they get. The key to your chemical-free success will come in the form of persistence. Outlast the blackberries and victory will be yours!
The best natural means of control is repeat tilling. Start by cutting the vines back down to the ground. Try to locate as many of the root balls as possible and dig them out. Follow this up with 10" of wood chip mulch. The mulch will block out the light and help prevent any seeds from sprouting. Over time, sprouts will invariably emerge through the mulch. When they do, till them under. Without leaves to produce food the roots will eventually starve and die. Tilling will fragment the roots and stems and cause them to re-sprout in other locations, so repeating this process several times may be necessary (this is the persistence part). Depending on how many vines you need to eradicate, you may be able to breathe a sigh of relief after a 2-3 years. A good time to start this project is in April.
Or you can smother them by covering them with layers of non colored paper, cardboard, black plastic or both.
I just cut, cut, cut. Cut down all the vines into pieces small enough to send put in the garbage can or the yard waste. They will grow out of your compost so that really doesn't work. Everytime you see some growing back, cut them down.
They will grow back up for a long time but once most of the vines are down, you just need to keep clipping the new ones growing out of the roots. They do send out runners so make sure you get all of them.
You can try to dig out the roots but it is a lot of work. Covering them with black plastic or paper will work if it is not a large are but they will send runners out to the edge of the plastic and start growing there.
Susan from ThriftyFun
I find that 1 gallon of vinegar (white), 1 cup of salt and a couple of tablespoons of dish soap put in a sprayer then sprayed early in the morning will kill just about any plant you spray it on.
I have not dealt with blackberries (will soon at my son's) but I boil the white vinegar down to 1/2 and dissolve the salt in hot vinegar. I hand spray it for edging garden, flowers, sidewalk cracks, etc. Does well on weeds, grass if used on a warm, sunny dry day, no rain immediately. As good as Roundup.