What is mulch?What is Mulch?

Mulch refers to different types of protective material gardeners spread on top of garden soil. Many people use natural, organic material such as compost, shredded wood, wood chips, pine bark, leaves, or straw because they offer an additional benefit of returning nutrients to the soil as they decompose. Newspaper and cardboard are also good mulch material that decompose over time. People also use inorganic materials such as landscape fabric, plastic, or stone, or some combination thereof to ease maintenance and fight particularly stubborn, invasive weeds.

Consult any gardening expert and you will hear about the benefits of mulch. Mulch is a key element for successful gardening: it helps keeps the soil cool and moist in the heat of summer, and insulates against the cold in early spring and fall. Mulch also suppresses weeds that compete for precious resources such as water and nutrients and helps prevent soil compaction and erosion.

If you’ve done your research, you probably already know by now that you need to mulch. But, what may not be clear is how—exactly—to go about applying mulch. And, what should the mulch be made of? Where should you get it? When should you mulch? What else do you need to know about mulch? We have some answers to help you get started.

Which Type of Mulch is Best?Which Type of Mulch is Best?

Generally, we recommend using organic mulch since it decomposes naturally and supports the ecosystem.Therein lies the rub, though: since it decomposes, it must be replenished regularly—which in many cases would be at the start (and maybe the finish—more on this later) of the gardening season each year. While that may sound like a lot of work to the uninitiated, remind yourself that you didn’t take up gardening because it was easy… procuring and spreading a fresh layer of mulch every year is just part of the job. The effort is well worth it, in terms of decreased maintenance and better plant growing outcomes and a natural garden aesthetic.

So, the question becomes which type of organic mulch do you use? There are many options, a few of which we listed above. Among the most common are shredded wood, wood chips or pine bark: they’re relatively inexpensive and easy to obtain. They also do a good job protecting your garden plants and suppressing weeds, though they don’t return as many nutrients to the soil as some other organic materials.

Shredded fallen leaves make excellent mulch if they’re dense enough to remain in place and you don’t mind the way they look. Otherwise, you could add a thin layer of shredded wood, wood chips, or pine bark on top of them.

As we mentioned above, you can use everyday household materials such as discarded moistened newspaper and cardboard which are safe for the garden and decompose naturally—though more slowly than the organic materials mentioned above. Arguably more unattractive than leaf waste, you could also camouflage and weight them down with a thin layer of wood mulch or straw.

Where to Get Garden MulchWhere to Get Garden Mulch

Wood based-mulch and straw are generally readily available from local and commercial sources. For mulching small areas, you can buy wood product mulch in two-cubic-foot bags from your local garden supply store. For larger areas (and to avoid all that plastic) you can also buy mulch in bulk, sold by the cubic yard. One cubic yard of mulch is equivalent to 13.5 bags of mulch.

There are also likely sources of free wood mulch near where you live. If you live in an area where there are a lot of trees, there is undoubtedly ongoing tree work which produces a plentiful supply of leftover wood chips. Many municipalities stockpile wood chips for use by local residents. Otherwise, you might contact local commercial tree services and find out if they have a supply of free wood chips to give to a good home. (If so, you will probably have to pick up a load yourself from their premises unless you can cajole them into dumping a load in your yard if/when they’re in your area). You can also ask your neighbors if they have any to spare.

How Much Mulch Do I Need?

For best results, spread a three-inch layer of mulch over your garden soil. If you’re dealing with an existing garden with mulch that simply needs refreshing, then add however much is needed to bring the mulch thickness to three inches. In either case, that raises the question of how much mulch you’ll need to procure in total. To figure that out you need to get at least a rough idea of how many square feet of garden area to cover—obviously, a tape measure is a handy tool for this purpose. Then, multiply the total garden area square footage by the inches of mulch depth needed to come up with the total amount. You’ll then need to convert the total feet to cubic yards. Don’t worry if you’re not a math whiz!  ‘Mulch Calculators’ abound on the internet and will do the work for you. Alternatively, any commercial garden supplier should know how to do the conversion and tell you how much mulch to buy.

Here’s a quick reference chart outlining how much mulch you would need for a 4’ x 10’ garden bed:

4’ x 10’ = 40 square feet 40 x 3 inches/mulch = 120 square feet of mulch needed

Mulch is typically sold at garden supply stores in 2 cubic foot bags. For the garden size outlined above, you would need to buy 15 bags of mulch.

For larger areas, you can buy mulch in bulk — by the cubic yard — but many bulk mulch suppliers require a 3-yard minimum for delivery. 3-yards of mulch at 3 inches deep would cover 324 square feet of garden area.

How to Mulch?

Once you’ve gotten ahold of some mulch, you can spread it on your garden beds, at will. There’s no way of getting around the fact that mulching is a physical-labor-intensive process. Obviously, having a sturdy wheelbarrow and good garden gloves and garden implements will help. You can spread the mulch in stages; it doesn’t have to be done all at once. The tricky part is being sure to spread the mulch evenly throughout your garden beds. And be sure not to pile up mulch high against the base of your plants; that may cause them to rot. Leave a tiny bit of space around the plant stalks.

When is the Best Time to Mulch?When is the Best Time to Mulch?

The best time to mulch is in mid-spring before the weeds have a chance to gain a foothold in your garden. Don’t mulch too early in the spring while the ground is still really cold or you may end up delaying or preventing your perennials’ re-emergence by trapping cold moisture in the soil. Spring is a busy time so don’t worry if you don’t get to it until after the arrival of summer. Like many things in life, applying garden mulch will be better late than never.

In some areas of the country, gardeners apply a thin layer of mulch in the fall to provide extra winter protection for their plant roots, especially newly-established plants. The mulch layers should never be more than three inches, so be sure to add extra mulch judiciously.

Once you’ve done it, you’ll realize there’s really not much to mulching your garden beds—except for the physical labor, that is. The trick is sourcing high quality, inexpensive mulch and figuring how much you need in the first place. You will find that the effort is well worth it.