If the condition of the old mulch has not decomposed appreciably by the time spring comes, it will still be usable. How do you determine its condition? Well, scoop up some of the mulch in your hands. Has it more or less broken down into fine particles, so that it is no longer clearly distinguishable from dirt? In that case, it will no longer function very effectively as a mulch; it is time to replace it. If, however, it has mostly retained the look and feel that it originally had, then you can re-use it.
The one exception would be if your plants in this garden bed had experienced disease problems last year that you think can be traced back to the mulch; in which case you would want to remove and dispose of said mulch properly (check with the officials in your town to determine a proper way to dispose of such material).
If upon inspection, you decide that the old mulch has not, in fact, decomposed appreciably, you should rake the old mulch aside for now so that you can prepare the planting bed. If you need to get it out of the way, shovel the mulch into a wheelbarrow, dumping successive loads onto a tarp off to the side. Apply compost onto the vegetable garden bed or annual flower bed, and till it under or work it into the soil with a spade. Then, re-apply the mulch you put to the side.
If the old mulch has, in fact, decomposed appreciably over the course of the winter work it into the ground as organic matter. So that it can serve as a soil amendment, along with the compost. Then acquire a load of new mulch as a replacement. A soil amendment is any material added to soil to improve its physical properties, such as water retention, permeability, water infiltration, drainage, aeration, and structure. The goal is to provide a better environment for roots. To do its work, an amendment must be thoroughly mixed into the soil.
Hopefully, this information helps you to improve your mulch beds and mulching areas! If you are in need of a new mulch supply this season, check out our shop for all your mulch needs!