Here’s more info about Cotton Burr, straight from the company’s website:
Cotton burrs are rich in carbon and protein. They also contain significant amounts of plant macro and micro nutrients. When composted, cotton burrs are a superior food source for beneficial soil organisms. In Nature, it is those organisms that convert nutrients in soil to a form plants can use, aerate the soil, and keep harmful diseases and organisms in check. In short, Back to Nature Cotton Burr Compost and Blends are unmatched when it comes to conditioning your soil.
Why mulching is important: it helps with weed control, keeps soil from drying out as quickly in the heat of summer, and enriches the soil as it decomposes.
Mulch — your garden will thank you!