there are exceptions to all rules. PI dies with minimal amounts of roundup. the secret is in applying RU with a small paintbrush on the leaves, undiluted, so that no other plant is affected. one or two leaves, touched with the brush, and the plant dies. As Kim says, there are giant roots under there, and PI will not get smothered. Look around for the larger vines climbing trees, they are particularly visible in Fall, when they are red against a bare trunk, and cut them at the base to eliminate the seed supply. They will produce a million small plants from the roots, and those you can paint next year to completely eliminate it.

Realizing this is an old thread I will add... I also don't like to use weed killers. Manual removal of poison ivy works best but seldom gets it all and can take years. A good use for those plastic shopping bags... Placed them over your gloves hands (w/long sleeves, right?) so when you grab the ivy you can pull it into the bag and turn the bag inside out to contain the ivy for disposal. Does that make sense? As mentioned you prob won't get it all so you can leave a length of the vine and treat it with some Round-up using a quart plastic bottle (milk or juice bottle, etc). Mark the bottle "Weed Killer" so it is easily identified.. Insert a length of the vine into the bottle. Trim the opening if you need to make it large enuff to get any leaves inside the bottle. Use a piece of string or wire to tie the handle to the vine so the wind or children don't remove or play with it. Then pour in a bit of Roundup so that it touches all the leaves. Shake the bottle daily or as many times as you walk by it - so the Roundup wets the vine and leaves. This also works for other invasive weeds/vines such as bittersweet. Esp. effective when a vine has just sprouted up in the middle of your perennial bed (to kill just the vine).

I have some blackberry invading a large climber. I will apply brush killer using a paint brush. I occasionally apply round up close to roses. I make sure that there is a stream instead of a spray and if somehow if I think I might have possibly got some on rose foliage, I remove the foliage immediately. If you have a lot of roses you can expect to have to replace a percentage of them, because stuff happens and you replant and move on.

I just want to give an update on my poison ivy. After due deliberation and much consideration I decided I could carefully target just the poison ivy leaves with an Ortho poison ivy killer without it getting into the ground. I began with a small area first and waited to see what would happen. At first I thought perhaps it had no effect at all, but then a few weeks later I noticed that tiny patch I'd sprayed was brown and dead. So I sprayed the rest. It took a lot of patience and a couple of rounds to get it all and is a slow process just as daninthedirt said, but it looks as though it has finally succeeded! So my next step will be removing that patch of dirt and hopefully removing any roots with it and then bring in some fresh dirt. I figure that's the best way to assure I'm removing as much poison residue in the soil as possible. I'll wait awhile before doing this step to give the poison a chance to complete its job on that root system. I, of course did these courses of poison during long stretches of dry weather so it didn't wash off the leaves. Next time this problem arises I'm going to try the vinegar recipe method for comparison. Thanks for all the help and good advice!