controlling blackberries

Is there a method of getting rid of blackberries where they are not wanted in our fields?
Most are away from our well 200 ft+ plus but still would prefer a non-chemical method of spray or ??? to control. Digging out the main root helps for a couple of months but we never seem to get all of it.
The fields are used by our horses.
We already have enough to eat so that is not an option.
Lower mainland area of BC

 

Unless you're prepared to be on a weekly vigil, you'll have to use "Round Up" in conjuction with good old fashioned digging. Not an option in most peoples neighborhood is an H Bomb.

 

I use a herbicide product called Diphenoprop (basically 24-D) it is also known as (brushkiller) to control blackberry. It is very effective. Can be purchased at 2 places in Abbotsford, and as long as you are using this product on your own property, I'm pretty sure you don't need any pesticide applicator licence to purchase it. TerraLink Horticulture and Evergo Sales, there both on Riverside Dr.
This product will greatly eliminate your blackberry problems. Depending how isolated they are from other blackberry patches not being treated, you may be able to rid them for good. If you are going to spray, stop cutting them down and let all the stocks and shoots get some foliage on them.
It is a selective herbicide and wont hurt any of the grasses in your pasture, and most people let there horses out they day after I spray, and horses don't bother with the blackberry anyway. Jim

 

Organic weed and pest control suggests that goats will eat the new shoots. I'm not sure if goats are compatible with horses in the same pasture, though. If you have already taken steps to remove the older plants by hand, and the problem is now reinvasion, this might be an option.

 

I haven't tried goats but just about everything else. Digging out the well developed major roots takes care of an initial crop okay but the re-invasive generations spread by birds, the wind, or the devil is another matter. The hair line ends of these roots are usually very deep if not dug out early. Round up & other pesticides will eradicate them but one needs to continually monitor for another re-invasion. Doing this for 5 or so years gets them fairly easy to control.

chrs/ciao,
floyd