That DB is grafted on Dr. Huey. I don't recommend amending the hole except for adding the superphosphate (put it in the hole then cover with soil, then the plant). I usually amend the entire bed in the fall, but you don't say if your soil is sandy and needs the amendments. You want to avoid what we call the "bathtub effect" where the hole retains too much water and it doesn't drain out properly. Here we may or may not have that problem because of the sandy soil (in some cases). Make sure the union is 2" below the soil. Don't "tamp". Backfill and use water to fill in the holes. Use your hands to press in the soil to make sure there are no air pockets. But you don't want to compress the soil around the roots. Mulch the soil, but keep the mulch away from the canes. Water after you plant, then monitor the soil. You shouldn't have to water daily, especially since we are due for more rain this week (thu - sat). You'll probably get in two applications of Rose-tone, July and August, then stop (no fertilizing after August). Once you see new growth after planting, you can try a weak (1/4 - 1/2 strength) solution of fish emulsion once a week until you start the Rose-tone. You're going to need a regular fungicide treatment for DB.

It does not have the characteristics of a fern from the pictures. The leaves curl I think it could be Curly Dock.

Realistically, you have two choices with a well grown invasive plant like this bittersweet. One is to cut to the ground all vines and on the fresh cuts paint a brush killer. Yes, it uses herbicide, but in smaller, very targeted use. This might take one repetition, but I haven’t had times when even a well established invasive takes more than one repetition. Otherwise, cut all the stems, and as soon as it resprouts, remove them before they are fully leafed out, and then repeat for the next two or more growing seasons every week or so. The goal here is to prevent it ever regrowing enough leaves to create energy so that the plant uses up all its reserves and is unable to replace them. With bittersweet, new stems won’t just grow from the main stem area, but will sprout from roots as well. If you let it establish leaves, it will start replacing the energy it used up trying to regrow, so this will take persistence and consistency. When a plant is really large and inter-grown with other plants like this, you won’t be able to remove all the roots with anything less than a tractor or bulldozer.

I don’t know what the 5 year life cycle refers to, and I would check the reliability of the source before believing it. One strategy I use for finding more reliable, scientific sources, is to use the scientific name, in this case Alliaria petiolata. Then I check the URL. Botanic gardens, state DNRs, and universities will be more reliable than something like a backyard gardener’ blog generally speaking. IME it grows a rosette of leaves and then shoots up a flower stalk, sometimes the first year and sometimes the second, depending on when it sprouts and growing season length. I try to pull before it flowers, especially during times the soil is moist so I can get more root. IME the seed has a long life in the soil, so you will always need to be vigilant. Learn what the small seedlings look like and smell like so you can pull them as soon as you see them. It may take more than 5 years of keeping an eye out because any time the soil is disturbed (planting, critters like chipmunks, voles, etc) there is the potential for deeply buried seeds to be brought to a better spot for sprouting.