If you want to spend less time weeding and more time picking flowers and veggies, size up your options for mulching your plant beds. Except for early spring crops that need sun to warm the soil, every plant benefits from a mulch.
Trees and shrubs will live longer without the competition from grass or the bark damage from weed-wackers. Smother the surrounding grass with a foundation mulch of overlapping sections of newspapers or sheets of cardboard—if you deny a plant light for 2 months, it will die. Then cover with pine bark, pine straw, wood chips or leaves. Put down the mulch about 3" deep--the mulch should cover the length of your middle finger if you're touching the soil.
Don't let the mulch pile up on the stem or trunk--moist mulch invites pest and disease problems, so leave a little space.
In the perennial bed a mulch keeps sunlight from reaching the soil to germinate weed seeds. Smaller particles make a better-looking mulch, so use ground pine bark mulch, seasoned sawdust or triple shredded hardwood bark mulch or my favorite--shredded tree leaves.
Too thick a layer can cause disgusting root rots on hairy-leaved and succulent plants that tolerate dry conditions, so don’t let mulch pile up around the crowns of these plants.
In the annual vegetable garden an insulating layer of mulch keeps the sun from steaming the moisture out of the soil and toasting the roots.
As the mulch decomposes it becomes an organic food supply for the earthworms and microbes that make a soil rich and able to best support garden plants.
I think the best season to apply mulch is winter--especially around January and February. It's cool enough to work hard and not break a sweat. And the bulbs and perennials are dormant, so they are not in the way, making it much easier and faster to spread the mulch.