Garden mulch is your first line of defense against weeds. But mulch is more than a weed-fighter. Mulching is one of the most beneficial practices you can adopt to maintain the grounds around your home. In this article you will learn:
- How mulch differs from compost
- Ideas for cheap or even free mulches
- When to apply mulch
Garden Mulch vs. Compost
A distinction must be drawn between mulch and compost. The two are not synonymous, nor do they serve the same function.
Compost is a soil amendment and should be worked into the soil to make it more fertile. Mulch, by contrast, is spread atop the soil. Its job is to:
- Suppress weeds
- Protect the soil from the elements
- Retain moisture
- Reduce the chances of your developing compacted soil in well-trodden spots
While organic mulches eventually decompose, thereby becoming a sort of compost, their function as long as they serve as mulch is distinct from that of compost.
Some gardeners try spreading compost atop the soil around plants in hopes that it will do double duty (fertilizing the soil and suppressing weeds). This is all right if you have more compost than you need and energy to burn. But compost exposed to the elements loses some of its "juice." And the weeds will grow like crazy in it unless you regularly hoe around your plants to keep the weeds down, which means extra work for you. So, on both scores, this use of compost is self-defeating and inefficient. It is better to water the compost into the soil (you can further work it in with a pitchfork), then cover it with a true mulch such as bark mulch.
Free Mulches: Using Leaves, Newspapers
Leaves readily suggest themselves to many gardeners as a possible mulch simply because they are so prevalent. Since they are free and we have to rake them up, anyway, we figure that we might as well put them to good use and save ourselves from having to buy mulch from someone else.
You can immediately use leaves you have raked off the lawn in fall around vegetables, shrubs, and trees, but always shred the leaves first before using them as mulch, and prepare your garden properly before adding any kind of mulch. You can also use leaf mulch as a protective covering for the winter in perennial flower beds, but hold off until the ground over your perennials has frozen, as a premature application could smother your plants.
Recycling newspaper as a mulch is another of your free options. But you must know:
- Whether or not it's safe
- Precisely how to use it as a mulch
Old newspapers are not safe for compost (older than 1990)—especially if you are raising food crops, as opposed to ornamentals. This is due to the composition of the ink, which includes toxic ingredients such as cadmium, lead, and chromium. Traditionally, harmful chemicals were used in the bleaching process.
Newspaper Mulch and Safety
Most newspaper inks of the 21st century are soy-based and regarded as safe. To make sure, call the publishing headquarters of the newspaper in question and find out if they use soy-based ink. If they do, the newspapers may be relatively safe for mulch and compost. While you have the publisher on the telephone, ask how the paper is bleached. More commonly, today, hydrogen peroxide—a safe alternative—is used to bleach newspapers.
If you wish to be a real stickler about it, ask a separate question regarding their colored pages (if any), as the inks used for these pages may contain harmful ingredients. Or, to be on the safe side, simply keep the newspaper pages with colored ink out of the garden.
Using Newspaper as Mulch
A material does not need to be fertile (as in containing a lot of nutrients) to do a good job of suppressing unwanted plants. Newspaper is particularly useful as a mulch when you are trying to open up a new planting bed by killing grass and/or weeds across a large area. Because it comes in sheets, it is a ready-made barrier and easy to work with. You can quickly cover wide swaths of the earth with newspaper.
When using newspapers as a more conventional mulch—such as around plants—lay them just two or three sheets thick and poke holes through them in such a way that water can penetrate to the plants' roots. Spreading a natural mulch, such as straw, on top of the newspapers will help hold them down; this will also improve the appearance of your garden because newspapers are an eyesore.
Cover Crops: Mulches That Are Cheap, "Living"
If you need to mulch a large garden in fall, and you don't have enough leaf or newspaper mulch for the job, seed the area with cover crops—live plants that are sometimes called "living mulches." Cover crops are an alternative to mulching with bark, leaves, or other conventional mulches to protect your soil for the winter. Cover crops are also sometimes referred to as "green manure crops." They derive the name from the fact that, once tilled into the garden, they fertilize the soil—as would manure.
Some gardeners choose to use cover crops in both their capacities: as "living mulches" for winter protection and as "green manure crops" that will be tilled under in spring. After tilling the cover crop under, apply a conventional mulch onto the garden to suppress weeds for the spring and summer. Living mulches are not free (you have to buy the seed), but they are cheap compared to having to buy bark mulch, etc.
When to Apply Mulch
New gardeners learn quickly that it's helpful to apply mulch during the growing season, but they may be unaware that fall is also a great time to mulch. Garden mulch applied in the fall keeps the severe weather conditions of winter from eroding your soil and robbing it of valuable nutrients. As an insulator, mulch works in two ways:
- It shields your plants' roots from some of the worst of winter's cold, sometimes making it possible for you to grow plants that are only borderline hardy for your region.
- By insulating the frozen soil from the sun's rays on that odd mild winter day, your plants will remain in their protective state of dormancy.