Yes, it's that time of year again - we're trembling on the edge of spring, I am seriously thinking about getting back into shorts for work, and the Sedum are looking brown, tatty, and no longer bring joy and uplift to the hearts of their owners.
Many people like to leave them up for as long as possible, for the "frost display" (excuse me while I laugh in a hollow manner, as in the UK, we rarely get strong, dry, crisp frost: we usually get a ton of damp weather beforehand, so our "frost display" is more likely to be blackened mush than anything else) but there comes a point where they have to be cut back, and NOW is that point!
As you can seem the new shoots are just starting to sprout, so if you leave it much longer, you won't be able to cut out the old brown stems without damaging the fresh new green ones, and that would be a bad thing.
So break out the secateurs, put on your gloves, and carefully snip off all the old stems, as close to the base as you can.
Don't be tempted to pull them off: they don't snap, and you will find yourself holding a dead brown stem with a piece of Sedum sprouting from the bottom end. These scraps are invariably too small to be worth planting elsewhere, so they tend to be thrown away, so take the time to cut them off neatly.