This variety grows anywhere from 20-25 feet tall and about 10 feet in width, so a relative dwarf among M. grandiflora varieties but the space is absurdly small. I am not sure you realize how exuberantly a heathy M. grandifora grows if happy. Growth is also frequently, very low branching (as in down to the ground). They are also strongly surface rooting, and I don't see how the roots are going to grow without destroying your pavers. I definitely would transplant ASAP, this is a small one. small ones transplant quite well but larger ones resent being moved as may be damaged or killed in the process. I have had them pop up from cones on my property and have removed the small ones to containers for future planting, so it can definitely be done successfully. I have several cultivars of M. grandiflora; Edith Bogue, Victoria, Majestic Beauty, and Little Gem. Little Gem is probably the most dwarf but still too big for this strip, and it's also the LEAST cold hardy. This is Edith Bogue obscuring a three story home. I planted it from a two feet tree about 15 years ago.

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.

And for removal of invasives (which this isn’t), I use large adjustable pliers to pull ones that are smaller. The looser the soil, the larger the plant you can pull. For large ones there a few choices: - Get a weed wrench or similar tool to pull midsized plants. https://www.theuprooter.com/tool-features/weed-wrench-alternative/ - Cut to ground level and then revisit each plant about every other week for a couple of seasons to remove all new sprouts so the roots use up all stored energy. This takes both consistency and persistence because if leaves get a chance to form the plant will start making and storing energy again. - Cut to ground level and then paint the cut with a short lived brush strength herbicide. I use this option along with the first because I live on 200 acres and it is my only hope of decreasing my invasives. I like it as the lesser of two evils because it is very targeted to individual plants, and it uses the least possible amount. I do recheck certain invasives even after this treatment once because sometimes buckthorn repsprouts, but IME recutting will kill it.

Rubus of some description. A bramble. Prickles are just visible on the top one.