What Is Mulch?

To give you a better idea of which mulches fall in the organic category, here are the most common types of organic mulch:

• Wood Chips: Available in various colors, such as brown, black, and red, wood chips are ideal for controlling weeds in gardens and pathways. Shredded wood is affordable and lasts up to 2 years.
• Wood Nuggets: Larger than wood chips, these nuggets are less likely to get blown away by the wind and can last up to 4 years. With their low pH of around 3.3 to 5.0, they’re perfect for flower beds of acid-loving plants like hydrangeas, gardenias, and azaleas.
• Wood Bark: Another type of wood mulch, shredded bark has more of a fibrous texture since it’s made solely from tree bark. While it can last up to 7 years, it’s better to replace it once it fades or every 2 years. Wood bark would look good in pathways and around trees and shrubs.
• Straw: This can be a good choice if you don’t mind adding mulch often, as it only lasts 3 to 6 months and decomposes after a year. Made from wheat, barley, or rye stalks, straw mulch helps retain moisture and prevent soil compaction. Usually yellowish-tan in color, it’s lightweight and perfect for protecting germinating grass seeds.
• Pine Needles: Sometimes called pine straw, this type of organic mulch can also help prevent weeds and moisture loss. Usually reddish-brown, pine needles can make your flower beds and landscaping beds more beautiful. Lasting up to 2 years, pine needles can interlock and form a stable layer, resisting wind and rain even on slopes.
• Compost: A decomposed organic waste rich in nutrients like carbon and nitrogen, compost can help enhance soil health and suppress weeds at the same time.
• Grass Clippings: You can get this nitrogen-rich mulch for free when you mow your lawn using a mulching mower. They break down quickly, though, so they only last up to 3 months. But according to Andruczyk, grass clippings are a great way to recycle nutrients and prevent organic matter from going to the dump.
• Shredded Leaves: If you have trees in your yard, you can easily obtain this mulch. They last 6 to 12 months and are best used around trees, shrubs, and flower beds. Shredded leaves can help improve soil health and retain moisture.
• Cardboard: For stopping weeds, sheet mulching with cardboard is the most effective. Until it decomposes after 4 to 6 months, the cardboard will create a solid barrier that weeds won’t be able to penetrate.
• Newspaper: Don’t throw your old newspapers into the recycling bin, as they’re also an excellent weed barrier (4 to 5 sheets thick). And they’ll add carbon to the soil once they decompose after 3 to 6 months. Since colored inks usually contain metals, use only the black and white pages.
• Coco Coir: Made from coconut husks, coco coir is a sustainable and better option than peat moss. It’s excellent at retaining water and improving soil aeration, making it ideal for flower beds, vegetable gardens, and potted plants. This fibrous mulch breaks down slowly and lasts up to 2 years.
• Cocoa Bean: Cocoa bean mulch is made from cocoa shells, providing nutrients like nitrogen and phosphate. However, it’s best not to use it in areas where pets can accidentally ingest it.

Pro Tip: When using newspaper or cardboard mulch, lay them carefully and overlap to avoid gaps. Otherwise, weeds can still grow through the gaps. Also, add 2 to 3 inches of either wood mulch or other organic mulch to make it pleasing to the eyes.

See Related: Is It Better to Rake or Mulch Leaves?

If you don’t like having to replace your mulch often, your best bet would be the more long-lasting inorganic mulches. The most popular types of inorganic mulch are:

• Stone/Gravel: A long-lasting and low-maintenance mulch, stones are ideal for pathways, trees, and steep areas. They come in various types, like pea gravel, marble chips, and river rocks.
• Rubber: Made from recycled tires, rubber mulch can last up to 20 years and comes in various colors, including blue, green, and gray. It suppresses weeds and provides cushioning, but has a strong odor that can be repulsive to some homeowners.
• Shells: Bring the beach to your yard by adding shells to your pathways and landscaping beds. Made from crushed clam, oyster, or mussel shells, this inorganic mulch can last for over 5 years with minimal degradation.
• Landscape Plastic: A solid sheet made of plastic that blocks sunlight and weeds completely. However, it can also restrict water and air flow to the soil. For a more eco-friendly option, you can use a biodegradable mulch film as an alternative.
• Landscape Fabric: It’s similar to landscape plastic but allows water and air to pass through. Apart from lasting longer than plastic, landscape fabric is also more aesthetically pleasing.

See Related: Pros and Cons of Using Landscape Fabric

• “Frost Heaving and Herbicides.” By Dwight Lingenfelter, extension associate. PennState Extension.
• “Knowing Better: The Appropriate Use of Landscape Fabric.” By Amanda Bratcher, extension agent. North Carolina State Extension.
• Michael Andruczyk, senior horticulture agent at the Virginia Cooperative Extension. Personal interview.
• “Mulch.” By Marjan Kluepfel, former horticulture information specialist, and Robert F. Polomski, PhD, associate extension specialist. Clemson University.“Mulch Plays Important Role in Gardening.” Oklahoma State University Extension.