You’d stand a better chance if you make smaller cuttings. Rosemary roots very easily from short lengths taken in midsummer.

However, if you don’t want to do that there’s only one way to find out. But I really don’t think it’ll work due to the size of the piece, the time of year and the fact that it is already somewhat shrivelled,

I'm pretty sure - like 95% - that you will not have success attempting to root those entire stems. Rosemary does not have a reputation for striking well from hardwood cuttings. Even from much more manageably sized ones. Those are huge for hardwood cuttings for any species!

OTOH, springtime softwood cuttings root fast and easily and also grow pretty rapidly. You should have a reasonably sized shrub by its second season after planting.

Oh bummer. For rooting this plant, I guess it likes a moist soil, but fast draining?

If I attempt to root it from the entire stem, I guess it will become clear quickly that this is not working since the leafy stems will start to dry out? Assuming it is going to root, it may take until next spring?

From what I can see the leaves are already pretty dry. Personally, I wouldn’t use material so dehydrated for cuttings. I’d just use that branch in the kitchen and ask the neighbour if they have any pieces which already have roots.

@ken_adrian that is probably a good plan. The green sections probably just put a burden on the mother plant without roots.

These were taken as two inch pieces. They rooted in a few days. You have nothing to lose by trying your giant cutting but I doubt very much it’ll work. And, as I said, I believe it is probably already too shrivelled to take even small cuttings from. Note the angle and turgidity of these leaves compared with your crispy example.