Such a short, simple word. What is mulch? Mulch is a semi-worthless material with awesome benefits! Compost is nutrient rich and helps plants grow, but mulch is the original herbicide! Fewer weeds means more nutrients for your crops. Mulch should never have plastic under it (this is evident a few years after being installed). Rubber and rock mulches never break down and become problematic if you (or future owners) ever want to revert a space into grass, garden, or otherwise.
I have strip of rock and plastic that was laid years before I bought the house and new layers of leaves, weeds, and washout from the rain have led to a phenomenal weed garden that is almost unworkable as lawn or garden space and keeps puking up bits of plastic sheeting when disturbed.
Mulch will help hold moisture in the soil for your plants instead of letting the wind carry away soil moisture.
Mulch will help prevent soil from eroding in wind or during rains. It prevents your soil from going fallow.
Mulch allows beneficial soil bacteria and fungus to take hold, which is where most of the god stuff in soil comes from. Collectively, these microscopic bugger’s in massive quantities will break down larger organic chemicals in your soil and make them very available for your plants.
Mulch helps attract surface worms like red wrigglers in my worm bins that break down leaf matter and other things that collect near the surface of soil. Mulch also helps with deeply burrowing worms such as earthworms, which bring minerals from below the surface of the soil, up into the rootzone.
Mulch begins to attract larger bugs such as predatory wasps that eat the bugs that love your crops.
But wait! There’s more!
Mulch can be used for footpaths, or patio space. It can surround perrenials such as trees, bushes, or asparagus and rhubarb if you are careful.
I use two types of mulch (maybe 3)… Wood chips and straw (not hay, which has weed seeds) are the two main mulches I control. I also use living plants as a green mulch. Comfrey is a ‘permanent’ perennial that could last 25 years or more. Squash is also a good, living green mulch and is is gone at the end of a season.
Straw is the reason we call the fruits of those 100 plants in my yard, straw-berries. This also helps with tomatoes and squashes and melons to keep the fruit off the soil, where it decomposes while it is still ripening. Strawberries grown on soil (no straw to keep them off the soil) have never survived to ripening without rotting wherever the soil touches them in my yard.
Mulch can vary from 3-10 inches, depending on your needs balancing with your budget, balancing with your limitations… The first two are easy to figure out, the third one was openly broad on purpose. Narrow walkways may fall apart if they are packed almost a foot high with wood chips. Ten inches of straw would hover over most spring strawberries and smother them.
Mulch does require annual maintenance since the good stuff breaks down into the soil, but it is only mulch, so how hard could it be to top off a little each year? Depending on annual precipitation, temperature, and biological activity, you may have to replace an inch to a few inches of mulch each year. Most of a thick bed of mulch will remain each year, in general. Installing it is the worst part.
Why go the route of mulch that requires maintenance when the rubber or rock stuff is maintenance free? First of all, humans change their minds from time to time. That plastic and stone stuff is harder to remove than it is to install… Natural materials just go back from whence they came within a short time, meaning you can probably get away with sweeping it under the rug and end up tilling it in, or covering it with weedless soil or sod someday.
Natural mulches also make for extraordinary nurseries for good soil stuff. Having mulched areas near crops, or anywhere really, means that the soil under it is healthier and that it is actively trapping carbon.
Mulch can also attract slugs, which are the #2 reason for losing strawberries around here. We fix those slugs with beer traps in the garden. It is fun setting some beer into glass traps (old garlic jars work great since they are small and have a sort of ceiling where the lid is smaller than the sides of the jar)… One sip for the garden, one sip for the gardener! The slugs smell the fermented brew and cannot get out of the trap. Our chickens love those slugs! Nothing gets wasted around here (except for us when we set those traps)!