I'd love to take them off your hands!

I love John Fanick phlox too! Mine spreads like that, but I don't have it planted by my irises, since they need less water here. You could put some lawn edging between them and pull up anything you see trying to escape!

Good advice, Sall20, but too late. I pulled up the invaders last summer, but that didn't get rid of the runners creeping underneath the iris rhizomes. They're as bad a bermuda grass!

This might be a job for ... manually weeding out the offending parts of the phlox!

LOL, purslanegarden! I'm headed out to do that very thing as we speak! :-)

I didn't know Fanick's phlox would spread like that. They, and other varieties of Phlox paniculate, are a mainstay in my yard, but I keep them in big pots because they dry out too fast in the ground here.

Our Fanick's phlox have not spread enough yet to be a problem, but do have to shovel prune last year's expansion off the periphery of the monarda and Maximilian sunflower patches each spring to keep them in bounds. Have to dig them back far enough that they can't make it into the neighbor's yard or surrounding plants within the single season. Removes a surprising number of plants. Seems like the only preventive option other than a hard barrier.

We're dealing with the campsis radicans among our irises by applying a strong herbicide through the cut stem using a floral tube, which is very effective and does a good job of minimizing damage to the surrounding plants. Seems you could use this on phlox if you first isolate the invaders from the parent(s) you want to keep. This has been the best option we've found so far for suppressing bamboo, honeyvine, and Virginia creeper within established beds without having to tear them up.

@bostedo. how do you use the floral tubes? I have some elms growing thru roses and they'be become to stout too yank out w/o hurting roses. How would you use the tubes? I would have sent a private email but I don't know how

Great pictorial Bostedo.

and then you yank the dead vine off the ground? that is fantastic. I wonder if it would work for elm seedlings. don't see why not. thank you so much, very, very useful.

Using floral tubes in the way described above to kill tough vines is genius!

For seedling trees that are too large to pull up I cut them close to the ground and apply a drop or two of full strength weed killer to the stub. It works very well on the Hackberry and other trees the birds plant along fencelines, etc. Some of the tree are quite large by the time I get around to trying to remove them from my sister's fence line where I planted Old Blush roses. The young trees hide among the rose canes and sometimes I don't notice them until they are up above the rose bushes. It still works on those big guys. A drop full strength on a phlox leaf creeping among the iris would work too. Wear gloves and be very, VERY careful not to get it on your skin or inhale any fumes.

OK, roselee, I'll give it a try.

i have droppers somewhere around here. Is one application enough? Do you let them die in place or remove after a while?

I cut the tree seedlings fairly close to the ground so they just die in place and don't need to be removed since the mulch I use covers the stubs. With the hackberry trees that reach up above my sister's huge old roses I couldn't get into the thorny bushes to remove the stumps if I wanted to. With those being larger, sometimes the trunks are maybe an inch or two in diameter, occasionally they resprout from the base and have to be cut and treated again. But it sure beats trying to get in there and dig them out.

Realize this is probably obvious, but just in case.... however the herbicide is applied, you should cut through any rhizomes, stolons, or other connections between the invaders and the keepers. Doubt drops applied to the invading phlox would outright kill a connected "parent", but might weaken it.

and then you yank the dead vine off the ground? ...... I wonder if it would work for elm seedlings.

@vossner, Usually there is just a few inches of vine to snip off after it's dead. Included the longer section with leaves in the photos mainly to show the effect. I may be over cautious, but try to treat anything killed with herbicide like diseased vegetation - goes into the trash rather than the compost pile; another reason I prefer to apply as close to the root as possible. While the tubes should work on any plant with a small flexible stem, probably overkill for anything that can be terminated as Roselee describes. We do the same with well-rooted redbuds, hackberries, privets, oaks, etc using a small foam brush instead of a dropper.... though like the dropper idea for getting into tighter spaces without accidentally brushing herbicide onto the adjacent plants as I'm prone to do. The tubes are good for delivering higher doses to large persistent root systems (campsis radicans, honeyvine,...) or other plants that continue to sprout after other methods of application.

what I was doing was douse a piece of cotton or fabric with the herbicide, cut the un-yankable seedling as close to base as I could reach, and then fasten cotton to the wound using a rubber band. I wished I had a camera to show what happened. It killed the seedling but I had some dead rose branches. I suspect the damaged sections came in contact with the cotton (wind) and they got zapped. I may try one of the foam brushes. I have a tough elm seedling to eradicate.

Roses are extremely susceptible to herbicides to the point that some rosarians say they can by affected by picking up herbicide from the roots of the plants that you are killing. Probably best to use just a tiny drop on the stump if it's anywhere near a rose.

I agree. A drop on the open cut is all you need. I avoid messing with weed killers as much as I can and only use it when I can't get a weed tree out any other way.

I have an half acre nail of green briar that is all up in some trees and I might try a bunch of these methods. I mostly just don't go back there.