Widely available, shredded hardwood lasts from one to three years. It’s a good choice for creating a natural look in landscape beds and is especially eye-catching in woodland settings. It also works well on slopes and in flood-prone areas. Many gardeners use shredded hardwood for informal paths in a backyard.
Chopped cocoa bean hulls add a rich dark color to landscapes — along with an exquisite, chocolatey smell that lasts two to three weeks. The fragrance makes it a wonderful choice for front yard gardens or beds near outdoor seating. Cocoa mulch is pricier, but lasts one to three years and can be applied as thin as 1 inch and still provide effective results. Note: Cocoa mulch contains theobromine and caffeine, ingredients which can harm dogs. If a 50-pound dog swallows 5.3 ounces, seizures can occur; 9 ounces can cause death. Some companies clean their cocoa mulch with high heat to help remove these compounds. The bag should state what the product contains and how it’s been treated.
A favorite among vegetable gardeners, straw is the stalk of grain plants. It’s not supposed to contain viable seeds, but often does. (Hay, on the other hand, always contains viable grain heads.) When purchasing, ask for clean, weed-free straw. A great place to get it is through a local nursery that seeds lawns. You can also season straw and sprout any weed seeds by sitting bales outdoors for a few weeks. Spread straw mulch up to 6 inches thick. Lay it over three sheets of damp newspaper if you don’t have time to season bales. The newspaper helps prevent weeds from germinating. In vegetable gardens, till straw under at the end of the season.
A gardening best practice is to mulch grass as you mow and let clippings decompose on the lawn. But for those times when turf has grown too long, use bag clippings as mulch. Apply in a thin layer because clippings tend to mat. Grass decomposes quickly (in a few weeks) and makes a perfect top mulch for vegetable gardens or beneath shrubs. Never mulch with grass clippings that have been treated with herbicides or pesticides.
Autumn leaves offer a free, readily available mulch source. To prevent leaves from matting, chop them first using a lawnmower fitted with a grass catcher. Expect a mulch of chopped leaves to last up to one year. Leaves are great landscape mulch to place on planting areas — including empty vegetable gardens — heading into winter. They create an informal look that might be better suited for backyard areas. Wet leaves after applying to keep them from blowing away.
Homegrown compost provides an inexpensive mulch that adds nutrition and organic matter to soil as it breaks down. It typically lasts up to one year and looks nice enough to dress even high-visibility front yard gardens. Some municipalities collect yard waste and compost it, offering the compost free or at a low cost to residents. Learn if this compost forms in a pile that’s turned (that means it heats up enough to kill weed seeds and disease organisms). If the material is simply piled and decomposes without turning, there’s a chance you’ll inherit weed seeds and diseases. Bagged compost from a store breaks down in a few months. Use this as a soil additive in new gardening beds.
Spent mushroom compost is the material used to grow edible mushrooms. It contains several organic materials, including some kind of poultry litter. Some types, if not well-composted, can burn seedlings. Apply it one or more seasons ahead of time for fallow vegetable gardens (in late fall for spring planting). Alternatively, allow it to sit for a season before spreading. Mushroom compost is inexpensive in areas where it’s widely available; otherwise, it can be pricey. It has a nice, dark color that complements any landscape design. Some gardeners find the odor offensive and use it only in backyard areas. Expect it to last several months to a year.
Fresh Wood Chips
If your backyard has many trees and shrubs, consider investing in a chipper-shredder to create your own supply of wood chips. Fresh wood chips make long-lasting mulch — one to four years — when placed on top of soil. They won’t blow, don’t contain weed seeds and typically don’t float. Worked into soil, they rob nitrogen as they decompose, so keep them on top of planting beds. Wood chips create a classic look that blends with any landscape design. They also make a great material for informal paths.
In the South, pine straw is the mulch of choice because it’s readily available and low-cost — maybe even free. Fresh pine straw has an attractive burnt-orange hue that enhances any landscape, from formal front yard gardens to backyard vegetable areas. There’s no science to back this up, but common gardening wisdom says it helps reduce slug problems around perennials. Purchase pine straw by the bale, or rake it up from beneath trees. It lasts one to two years.
Most frequently available as a regional product, composted seaweed offers a free to inexpensive option for mulch. Expect it to last several months, at least one growing season. Packed with nutrition, seaweed compost adds micronutrients to soil as it decomposes. You can find some seaweed-based mulch that’s bagged and distributed nationally, like Fundy Blend Enriching Mulch (pictured).
Locally available materials — usually byproducts of local industries or agriculture — provide inexpensive gardening mulch. In some regions, crushed, dyed corncobs are the mulch of choice. Depending on where you garden, you might also find cottonseed hulls, fine forest mulch, salt marsh hay or crushed shells. Most of these materials last up to one year; some, like shells, last longer. Check with a garden center or local extension office to learn what types of materials are available. Ask if the material creates any nutritional imbalance in soil if you use it consistently over time. Sometimes it’s best to rotate local materials with other traditional mulches, like shredded bark or compost, to keep soil nutrition healthy.
For a mulch that doesn’t decompose, plant a ground cover to act as living mulch. Use plants like alpine strawberries (pictured), vinca vine or even dead nettle. When you plant living mulch, you can expect many of the benefits of traditional mulches — while adding beauty to your landscape design. Be sure to apply compost to planting beds annually to help nourish your living ground cover and build soil.
In the coldest regions, a layer of snow makes great winter mulch. When shoveling, toss snow onto planting areas to help insulate plants. Use care when dealing with snow that’s laced with road salt or salt-based ice melting products. Salts can harm plants if they occur in a high enough concentration.
University researchers have discovered that certain vegetables show an increased yield when grown on colored plastic mulch. The increase occurs most dramatically when other growing conditions are less than ideal. For instance, if your vegetable garden doesn’t receive 6 hours of sun, colored mulch may boost yields. The colors used are red for tomatoes and eggplant; silver for peppers; green or blue for melons; and blue for summer squash and cucumbers. Most plastic mulches can be reused for several growing seasons before they start to degrade. When purchasing plastic mulch, look for types with perforations that allow moisture to reach soil. Anchor mulches to soil with landscape pins.
Sometimes called weed cloth or weed barrier, weed fabric provides a useful mulch, especially in situations where you want long-term coverage for many years. Weed fabric is most commonly used beneath other types of mulch, such as stone or even shredded bark, but some gardeners use it solo, mostly on vegetable garden paths. If you use weed fabric beneath another type of mulch, stay on top of weeds. Do not allow them to grow, or eventually they’ll root through the fabric, which turns weeding into a nightmare.
Lighter weight than traditional stone, lava rock dresses a front yard planting area or backyard bed with eye-catching color. The edges are sharp, so it’s best used in places that don’t require much gardening maintenance. Lava rock lasts forever, so it’s an investment that definitely pays. Make sure you use it where you intend to keep it, though, because it’s difficult to remove.
Long-lasting stone mulch creates a formal look in a planting bed and is commonly used in Southwestern-style gardening. Stones absorb heat during the day and release it to plants at night. This additional warmth allows gardeners to grow plants that are borderline hardy and also jump-starts perennial plantings sooner in spring. The heat absorption can be a problem, though, as it can cause faster water evaporation from soil. This occurs most frequently with dark-colored stones.