Some of it is fairly obvious (such as remembering to remove any burlap that you have used for winter protection for shrubs), but other tasks are easy to overlook.
When to Take Mulch Off Perennials: the Long Answer
To a large degree, getting the timing right for mulch removal requires you to be observant regarding your plants and the weather conditions where you live.
If your memory is not good, it helps to keep a garden journal from year to year.
But, after a while, all of this should become second nature for you. You will know when spring is "here for good" in your region, and you will know when your perennials are really supposed to be pushing up new growth for the year. When, based on past observations, the time has come for spring to wrest control from winter (that is, the chance of suffering a hard frost has passed) and for a particular perennial to emerge from its slumber, you should begin checking to see whether the ground is thawing or not. If the ground is thawing, leaving landscaping mulch on top of your perennial flowers can smother them or invite harmful molds -- so it is time to remove the mulch, to let your perennials breathe.
While perennials sometimes will successfully break through a barrier of mulch, other times damage will result.
Don't take a chance with the health of your perennial flowers!
Even if a covering of mulch does not completely smother a plant, it can, at the very least, disfigure its leaves. Part of the beauty of a plant is its foliage and stems (vegetation). If the vegetation has to struggle to push up through a layer of coarse mulch, doing so may take a toll on the appearance of its vegetation, initially. While no permanent harm is done, this does temporarily mar the visual display for you. Since enjoying the visual display to the fullest is the reason why you are growing the plant, this is not an unimportant consideration.
Once the perennial flowers have pushed up and have achieved a bit of height, then you can re-apply garden mulch around them to suppress weeds. Shredded leaves make for an excellent mulch because they are light and fluffy; they break down readily and -- when they do so -- release valuable nutrients into the soil.
taken from https://www.thespruce.com/when-to-remove-mulch-for-spring-perennials-
till next time this is Becky Litterer, Becky's Greenhouse, Dougherty Iowa firstname.lastname@example.org