When we first started our new garden beds, we had small plants separated by a lot of soil. Nature abhors a vacuum, so this area would inevitably quickly fill with weeds.
We also wanted to keep these young plants moist. For both these reasons, mulch was the answer. Long ago, before we started thinking about the use of chemical fertilizers and pesticides, we happily collected all the neighbors' grass clippings.
Town truck collecting "waste"
This was before people started getting mulching lawn mowers. They simply bagged up the grass clippings and put them out to the curb, waiting for the town's huge fossil-fueled dump truck and payloader to come scoop them up and take them away. This was also before our county's Resource and Recovery Agency (OCRRA) heavily advertised their catchy "Leave your clippings on the lawn" jingle.
When we started feeling squeamish about all the chemicals in those grass clippings, we bought a chipper/shredder and shredded leaves to use as mulch. As time went by, however, our plants grew and spread, making it difficult to spread mulch between them.
In fact, not only difficult, but unnecessary! The beds became self-mulching. The canopy of leaves keeps the soil cool and moist and keeps the ground shaded so weeds don't grow as easily. And since we don't fanatically rake up all the plants' fallen leaves in the fall, they decompose and themselves enrich the soil. So now we just let plants grow.
A separate issue is mulching the paths.
First, we used landscape cloth as a base for all our paths.
As so many other people have found, landscape cloth doesn't prevent weeds from growing. They just grow on top of it. And it's a real pain to remove.
Second, we've read that wood chips may not necessarily be a sustainable product.
(Apparently, this is especially true of cypress mulch, though I don't think we ever used that type.)
We started by using mulch from the town and county mulch piles, free with a $10 yearly pass, so it felt like we were simply using something that was a waste product from the trees people were cutting down.
One year, we were fortunate to be able to rescue some wood chips that a neighbor on the next street put out to the curb after removing some trees.
A few times, though, we bought a truckload of mulch from a local garden center. (I don't know the source of their mulch.)
When we think of the huge amount of mulch being sold by the big-box stores, we realize that this isn't all being created by tree-trimmings. All those trees just to make our yards look neat?
We'll have to again consider this issue the next time our paths need mulch …