I don't know about the Crossbow product you mentioned, but I have had good success using the brush killer products that list poison ivy right on the front label. You can get in any home improvement store. The spray bottle has a 'stream' setting and on a windless day you can target just the poison ivy leaves and if you're really careful you won't get a drop on anything else. I have done this to eliminate poison ivy among other desirable plants (never daylilies) and the other plants were just fine. It takes a while (days) for the poison ivy to succomb, but it disappears completely. I would suggest trying this on just a small corner of your problem bed and then wait a couple of weeks to see what happens to both the poison ivy and the nearby daylilies. By the way, I don't think Roundup works on poison ivy.
Good luck. Christine

I use a paper towel tube to direct the spray.
Renee

I just pull any poison ivy that shows up anywhere in the garden. Happens fraily frequently. Best if you catch it while the plant is still small. I used to put baggies like for freezer bags over my hands but eventually just started pulling it barehanded. I go instead right away after pulling and wash my hands with cold water. So far, haven't gotten any poison ivy breakouts.

I've used 2,4-D in the daylilies, 1 ounce per gallon of water. Haven't used Crossbow though. The 2,4-D will make the daylilies twist some if used early in the year but they come out of it. It will also make the scapes twist if you spray while the scapes are forming. Give me a couple of weeks and I'll let you know how it does with daylilies that are blooming. I sprayed some the last couple of days trying to get a handle on ragweed and smartweed. I wouldn't necessarily want to use it on very young seedlings or newly lined out plants though.

Janet

Round Up will kill poison ivy. That is what I use on the Ivy in Georgia. I hate that stuff, my heart goes out to you having it in your daylily bed.

Ugh. My whole family has poison ivy issues except for dad--he just yanks it and tosses it. Unfair. I use a spray from Home Depot that's marketed for killing poison ivy and brush (it also works on stray Virginia Creeper, feral grapes and mulberry bushes). But when spraying in a bed I drag along a large piece of cardboard to shield surrounding, desirable plants from the spray.

I've also used Roundup's foam spray, but it didn't seem quite as effective at killing the poison ivy--I dosed it several times with the foam to get rid of it. The good thing about the foam is that there's no overspray; it just lands on what you're shooting at and sticks there.

Shame of it is, I know the poison ivy will be back next year. Alas.

-eric