Wondering why some gardeners use mulch on their plots?
There are many reasons to use a mulch and many materials work including, straw, shredded leaves, compost, coffee chaff, coconut husks, etc... (Wood chips do NOT make good mulch for food gardens, they rob nitrogen!)
• KEEP THE WEEDS DOWN.
Once you've weeded your garden, you probably don't want to spend that much time weeding again. Putting mulch down greatly reduces the need to weed your garden. Weeds that do poke through are easier to pull as the ground stays loose and moist (more on that below). Weeds compete with your plants for soil nutrients; help the good guys win!
•RETAIN SOIL MOISTURE AND MODERATE SOIL TEMPERATURE.
While we all know it rains a lot here, it can go months in the summer without raining at all. Mulch will greatly help the soil retain water, since it won't evaporate as easily. The deeper you pile it, the moister it will stay. During dry periods minerals are not as available to plants; keeping the soil moist solves that problem. In addition, mulch helps to regulate soil temperature. This is especially important for shallow-rooted plants. An added bonus: earthworms love a moist environment, and will multiply. They're good for the soil because they help loosen it up, and their castings are food for your plants.
•PREVENT THE SOIL FROM BEING COMPRESSED. When it rains, it can come down with brutal force. This compresses the soil, which makes it harder for tender young roots to penetrate. Also, root crops like potatoes and carrots like loose soil since they need to displace a lot of dirt. This is why it’s especially important to mulch your garden for the fall and winter months! (For these same reasons, it's a good idea to avoid walking in your garden when it's muddy.)
•INHIBIT VEGETABLE ROT.
Cucumbers and other vegetables that touch the ground can partially rot. Put a little mulch under the cuke, and it will be happier. Though keep in mind, it’s best not to mulch a whole area where viney things grow; they often need to put down roots along the vine, and this will be hard to do if the whole area is mulched.
•WINTERIZE YOUR GARDEN.
OK, it may seem a bit early to be thinking about this, but with our mild and rainy winters, we need to think about our beloved soil year-round. The continual rains can compact bare soil and wash important nutrients out of the soil. The good news is that with mild temperatures, our winter is THE ideal time to build soil with rich organic mulches. They slowly break down and add to the soil even while we’re cozily reviewing seed catalogs inside. Not to mention the great job mulch does at reducing weed growth in the early spring before we get out to the garden.
Look at the soil in the woods, which has leaves as natural mulch. It's dark, rich, moist, cool, loose, and full of worms; all things we're trying to attain by using mulch in our gardens. The soil life is fed in an ongoing, slow release way that helps the smaller organisms that build and maintain soil aggregate structure as well as providing additional organic matter as it is incorporated by worms.
This information pertains to organic mulches. Synthetic mulches like plastic or landscape fabric share some of these benefits, and have some of their own.