Mulching your growing areas are a great way to add organic matter compost to the soil as well as weed control. Forest floors are always covered with leaves in nature. Mulching regulates the soil temperature from temperature extremes that plants do not tolerate well.
Mulch also assists in holding in rain and snow moisture as well as keeping the top soil from being washed away in heavy rains. When you work hard to build up organic matter into the top soil, it is a shame to get it washed away in hours.
If you live in a rural area, you can look for mulch like leaves in the fall when people bag their fallen leaves from their trees. Ask if you can take them and put them into your gardens or compost pile.
Seek out the trash company and see if they grind up tree limbs cut from homeowners. Power companies tree trimmings for power line maintenance is also a source of wood chips. Tree cutting companies may also be a source of mulch. You may get this for free as it is sometimes considered trash for these sources.