Try Crossbow since Roundup by itself really won't kill the vines. I use a mix of both since we're usually killing grass at the same time.

We had a huge area covered with them last year and after cutting back as much as we could, we then sprayed the area. About half returned by the end of the summer so we sprayed again in early fall. There were no new sprouts this spring.

Glyphosate is supposed to be used on blackberries only during fall. At that time the plants are transporting nutrients from the leaves to the overwintering crown buds (from which new canes come the following year) and the herbicide may ride along with them and kill the buds. Even then it may take more than one year to finish them off. Spraying these spring and summer is probably pretty much a waste of time and money in most instances.

Coincidentally, I was just reading about blackberry management on this website:
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7434.html
It echoes what bboy says, but has some other useful information as well.

Good info on that link lisa!
The paragraph on the use of Triclopyr better explains the approach I use for control.

One also needs to be aware of the % of the active ingredient they're starting with so that they end up with a solution that will kill the vines.

I've heard that you could use agricultural grade vinegar to kill them, but you have to adjust the pH afterward if you plan on planting something later. I've never tried though. Just keep killing them and digging them up.

Thanks for the info! That link is quite good and confirms what I sort of had in my mind. It will probably take a while to get rid of them, or at least down to the point where I'm not seeing something new popping up every few seconds like that carnival game "Whack the Mole" LOL!

I saw something in Ann Lovejoy's book about agricultural vinegar and citrus oils but nothing specific enough to go out and try it. Do you know anything Winsorw?

I don't know about adjusting the pH of a soil like adjusting a TV. Each pH point represents a huge increment, if something causes the pH to plunge that must be highly disruptive to the soil system. And then it would take a lot of lime to bring it back up several points. It has been recommended that liming a soil to change the pH be done slowly, so as not to cause too much trouble. If that's the case what does something like strong vinegar do?

The soil is a community rather than a substance.

Blackberry vines, wild ( Rubus spp. )
• picloram

Tordon
Rate 1 lb ae with 50 gal of water for spot treatment sprays

Time Apply in late spring after leaves are fully developed.

Remarks Foliage must be thoroughly wet. Reapplication will be required as regrowth occurs.

Caution Most formulations are restricted-use herbicides. Do not contaminate water. Potatoes, beans, and many other broadleaf crops are sensitive to picloram. Do not use picloram in diversified cropping areas.
• glyphosate Rate Broadcast treatment: 2.25 to 3 lb ae/A. Spot treatment: 1% to 1.5% solutions.

Time Apply in September to October when canes are actively growing and after berries are formed. Fall treatments must be before a killing frost.

Remarks Fall spray treatment symptoms may not show before frost. Re-treatment may be necessary for complete control. Trailing blackberry is more difficult to control.

Caution Glyphosate controls grasses in the treated area as well as other vegetation.
• metsulfuron

Escort or Cimarron
Rate 0.3 to 0.6 oz ai/A (0.5 to 1 oz product/A)

Time Apply to fully leafed-out vegetation before fall leaf coloration.

Remarks Constantly agitate while mixing product in water. Add 0.25% by volume of nonionic or silicone surfactant to spray mixture. Good coverage is essential. Application sites differ between these two products; consult labels.

Caution Avoid contacting sensitive crops. Apply only to pasture, rangeland, and noncrop sites.
• amitrole

Amitrol
Rate 4 lb ai/A in 100 gal water/A

Time Apply July to August when the foliage is fully developed.

Remarks Foliage must be thoroughly wet, to the point of runoff.

Caution All commercial uses were designated as restricted uses in 1985. Registered for use on noncropland only.
• triclopyr ester

Garlon 4

or

• triclopyr amine

Garlon 3 A

or

• triclopyr + 2,4-D

Crossbow
Rate Spot treatment: Mix 3 lb ae Garlon 4 or 3.75 lb ae Garlon 3 A with 100 gal water, or 1 pint Crossbow in 12 gal water. Broadcast: Use 1 to 4 lb ae/A Garlon 4 or 1.5 to 4.5 lb ae/A Garlon 3 A or 1 to 2 gal/A Crossbow.

Time Apply when plants are actively growing. For dormant application, mix Garlon 4 in diesel oil or in water with 3% of an oil substitute.

Remarks Foliage must be thoroughly wet.

Caution Use on rights-of-way, industrial sites, and for forestry (release and site preparation). Crossbow can be used on permanent pasture and rangeland, up to 1.5 lb ae/A. Observe all grazing and harvesting restrictions.

Here is a link that might be useful: CONTROL OF PROBLEM WEEDS

High strength vinegars will not effectively control blackberry. Some years ago Lovejoy touted a newly marketed and unproven vinegar product as a sure thing to control thistles, blackberry etc, for an entire year with one application. It was later shown to be more hype than reality when it came to controlling these things.

"...an article by Ann Lovejoy, a free-lance gardening and food column writer for the Seattle Post-Intelligencer newspaper extols the virtues of Blackberry & Brush Block (we'll call it "B&BB" for short) as the "natural" answer for control of everything from annual weeds to Canada thistle and dock to Scotch broom and, of course, blackberry. Lovejoy notes that weeds quickly wither away after treatment, with a single application lasting up to a year. "No more weeds," she bluntly states. "Period."Lovejoy explains that "the (B&BB) concentrate takes the soil pH down to 3, a level at which plants can't survive" and that until lime is applied to vinegar-treated soil, "nothing will grow in that area." Dr. David Bezdicek, WSU Extension Soil Scientist at Pullman, says that given enough soil acidity, any weed can likely be killed. Dr. Craig Cogger, Extension Soil Scientist at WSU Puyallup agrees, although he points out that soils have a tremendous ability to buffer pH. Therefore, unless quite a lot of the product were applied, it is doubtful that a single application of even very concentrated acetic acid will have much impact on soil pH.Lovejoy counsels that "soil biota [the living creatures in the topsoil] simply go dormant, waiting for things to get better." OSU scientist Dr. William said that while "general knowledge about soil organisms suggests that some bacteria become quiescent under adverse conditions," most soil organisms "either move or die when conditions change rapidly such as [occurs in the event of] contact with concentrated vinegar or drastic pH changes." He acidly concludes that these and other claims about B&BB "may require your considered judgement."

Here is a link that might be useful: WSU article

Acidly? Of course.

I kill blackberries from Spring until Fall with either Roundup or Crossbow. I don't know why it doesn't work for some people. Maybe their solution is too dilute, or they are spraying just before rain, or they aren't covering enough of the foliage. About 10% of the time, the plants recover, and I need to respray later on. It's not a big deal. I killed thousands of blackberries at my new place last Summer, by spraying in May.

Mow them. If they are coming up in grass the mower will keep them in control.

What about the ones that come up smack dab next to the base of a shrub? I have been afraid to use chemicals there for fear of damaging the shrub. I cut off the stems at the base, over and over all summer, and hope someday it will starve to death for lack of whatever it gets from growth on top. My neighbor says there is only one blackberry plant in Oregon - but it covers the whole state! Seems that way sometimes.

Try to dig out the crown. If you can't then let it grow enough so that you can treat the leaves with Crossbow.

Kneewalker, I have had success with several methods.
1. You can cut the stems and then paint the cut "trunk" with concentrated Roundup. This is very safe. Use a Q-tip or small brush.
2. You can let the blackberry grow several feet long, then stake the tip of it down to the ground (away from the shrub) and spray as much of it as you can without getting spray on the shrub. Use the diluted Roundup for this. You don't have to cover every square inch of foliage with spray. A few leaves is enough.
3. You can drill a few holes in a big blackberry stem with a portable battery drill, then fill the holes with concentrated Roundup, using a nose dropper or something similar. This also works on bushes and trees.

Do not use concentrated Roundup as a foliar spray. It will just kill the leaves and not the plant. Dilute as per directions.

Minimize the amount of herbicide that gets applied to the soil around a desireable plant. Roundup is supposed to be inactive in soil, but I know from sad experience that it is not competely inactive. Do not spray herbicide near a desireable plant if rain is expected in the next couple of days. If you do, some of it will wash into the soil. A little paranoia will serve you well.

I don't spray weed killers as I don't want to be affected by them as well but painting the cut surface of canes has caused a year or two of freedom from vines in some areas, using undiluted brush killer or Roundup. I like a squeeze plastic bottle with hole in the tip to apply it. We also chip all the blackberry vines and use them for mulch so we get something out of all the work and scratches.

Thanks for all the suggestions. I will work up the courage to try them. I got just plain lucky when I moved here and got rid of the blackberries by digging - except for that one too close to the shrub. Noticed tonight there are blackberries creeping under the fence from the neighbor's yard. Darn!

I'm fairly new to PNW as well and have been happy about seeing a big new blackberry vine in our yard near the blueberry bushes. Now I'm wondering why everyone else is working so hard to kill them off ... are the volunteer blackberries not good to eat? Is there a specific kind to plant if we do want to have blackberries? We're 15 miles east of Portland.

Thanks ... off to do some more research on this.

The blackberries make delicious jelly , and are nice for other things if you strain out the large seeds. It is nice to have some of them to pick. It is not nice to find them coming up among your vegetables or flowers. THe problem is that birds love the blackberries and and what goes into the bird comes out again usually when they are sitting in a tree or shrub in your border! Thus you will always have to patrol these borders in springtime and dig out the new seedlings before they sink roots too deep. Continual mowing will control them where that is possible but most of us do regular blackberry patrol in our yards.

Minet,
I just moved to the PNW a year ago, and was also thrilled to eat blackberries right off the vine. However, having been here through a season, I see that they grow everywhere, and the creeping native blackberry will quickly cover a shrub in a couple months. Keep one area of them to eat, then get out all the rest, or you will have a blackberry farm with little else in no time. Enjoy!

Do cute pygmy goats eat blackberries? If so I need a small herd to eat a spreading to more than an acre of this vigorous rooting vine. My Aussie needs a job.

There are 3 blackberries that grow wild in western WA, western OR, SW BC and NorCal:

Himalayan blackberry, Rubus armeniacus, is a horrible weed. Grows huge, with fishhooks for thorns, and the berries while large and easy to pick are rather tasteless. Birds seed them everywhere. The individual canes can be very thick and woody and grow several feet a year. Almost like a climbing rose cane. Can cover bushes and small sheds, very difficult to control.

Trailing or evergreen or cutleaf blackberry, Rubus laciniatus, also a horrible weed, but not so widespread or so large as Himalayan. Wicked thorns, tasteless berries. Neither one is native.

The native blackberry, Rubus ursinus, aka dewberry, little wild blackberry, sometimes also called trailing blackberry. Absolutely positively delicious fruits, but small and hard to pick. Tiny thorns too, that embed themselves deeply and hard to get out because they're so fine and they break off at the surface of your skin. Thin, pliable, nonwoody, trailing canes. Berries in early summer, where the other two (nonnatives) have berries in late summer.

While thickets of the native blackberry can build up over time, I rarely see them growing more than knee deep, and relatively easy to keep under control. The canes do wind their way through shrubs but I've never seen them bury anything the way Himalayan and cutleaf do. The native berry mostly creeps along the ground.

I believe that people do use goats to control blackberry. An excellent job for your Aussie. I used to live somewhere where the city hired a guy with a flock of goats and a couple of border collies to control brush in their parks. the goats ate the brush, and the dogs kept them in place.

Reg, I enjoyed your post especially the part about the goats. That's not an option for me since I'm sure Billy isn't going to eat around my gardenias or the agapanthus LOL! I did try roundup which did not work for me. I bought the concentrate, diluted it as directed, and didn't water the garden for a few days just to be sure. They were hardly even knocked down but they did stop growing. For a while. I don't know what to do about it anymore and have resigned myself to yanking them out of the ground. Ann Lovejoy recommends cutting them but that only made the roots stronger and it regrew the tops. There is a golf course on the other side of my emerald cedar fence where they unfortunately do not take care of weeds so I might sneak over the fence on day and do some business myself.... PS: The blackberries growing in my yard are tasteless just like Reg described.

Cutting the tops won't make the roots stronger. And making the tops regrow over and over frequently (more than once per year) will have a depleting effect on the roots, over time.

The leaves make food which is stored in the roots. Energy stored in roots is used to grow new stems. Spraying glyphosate in the fall results in it being transported to the roots (crowns) where it can concentrate in the buds and kill them, preventing re-growth the following year. As is so often the case with pesticide applications, correct timing is everything.

Do not apply pesticides to property belonging to others without permission.