There is some kind of worm or larva eating this plan. It has done quite extensive damage in what seems to be a couple of days. It is not the first year this has happened. Is there any way to get rid of the worm so the plant can be saved?
Picture is included on the left is the creature eating the plant and the right is the plant and a sample of the damage.
Bacillus thuringiensis Bt is highly effective against most caterpillars and fairly specific to caterpillars, though it makes no distinction between "good" or "bad" caterpillars.
Generally good to try and identify what your caterpillar (not worm) is, precisely, before taking action. Caterpillars lead to moths and butterflies, some of which are rare and endangered as noted in @pazi_fitch's linked question. Despite being unsightly, the damage rarely kills plants (you note this is not the first year this has happened, and yet here your plant is, still.) Some are obnoxious invasives where killing them is a good thing, but many are "mostly harmless" on balance.
I would always recommend organic phosphorus like phoxim or triazophos against all kind of caterpillars, on non-edible plants, whenever your law permits. They are very cheap, extremely effective and just kill every caterpillar or worm of any species, without need to identify.
If you can identify them as butterfly or moth larvae, or your have pets/kids near it, then you can use Bt pesticides too, like Ecenerwal mentioned above.
