All About Mulch


Applying mulch is one of the best things you can do for your flower and plant beds, trees and vegetable gardens. Mulch is a layer of material, most often wood or rubber, that is spread on top of the soil to protect against erosion and conserve moisture.


Mulch has many benefits, but the main reason people use it is to boost their curb appeal and put the finishing touch on their landscaping. Additional benefits include helping plants maintain a more even soil temperature, slow evaporation rates during hot summer days, and prevent weed growth to reduce garden maintenance.


Before you buy mulch, consider the following questions:


        • Are you looking for a way to reduce weed growth?
        • Does your garden need mulch that will improve the soil?
        • When is it appropriate to use landscape fabric?
        • How much wood mulch should you apply for best results?
        • How long do you want your mulch to last? 


How Much Garden Soil or Mulch Do I Need?


How much garden soil or mulch do I need?


Garden soils and mulches should be applied at a 3-inch depth. Therefore, six 1-cubic foot bags will cover 24 square feet. For best results, keep the mulch away from direct contact with the stems of plants and trees to prevent rot and unwanted pests. Do not exceed the 3-inch depth as higher levels may prevent the roots from growing through the mulch to find water and nutrients.


To help you estimate how much mulch you need, visit our Mulch and Top Soil Calculator.

Mulch Types


There are two basic types of mulch: wood-based and rubber. Both act as ground cover and offer the benefits of insulating and retaining soil.


Wood mulch breaks down after a season or two and needs to be reapplied. It actually enhances the soil by adding vital nutrients as it deteriorates.


Rubber mulch is more permanent, but does not improve the soil structure.


Wood Mulch: Some wood-based mulch materials can be found in your own yard, such as leaves and pine needles. Hay and straw also work well, especially when you need mulch that is light and airy, such as for lawn cover after applying grass seed.


There are also varying types of wood chips and tree bark nuggets that can be purchased, including pine, cedar, cypress and other hardwood mixes.


Colored mulch also adds another finishing touch to your landscaping with red, brown and black being the most popular choices.

      • Wood mulch fertilizes sandy soil and helps hold water and nutrients.
      • Bark mulch lasts for one to three years, then may require reapplication.
      • Smaller wood chips are easier to spread around smaller plants.
      • Be aware that hay and straw mulch may harbor weed seeds.
      • Pine needles increase soil acidity, making them ideal for use around acid-loving plants.

Rubber and Other Types of Non-Wood Mulch: Rubber and stone are not as beneficial to the soil as wood mulch, but they last much longer.


Landscape rocks are often used on paths, around walkways and around permanent plantings, such as shrubs and trees, but do not work well for vegetable or flower gardens.


There are many shapes, colors and types of decorative rock that can be used as mulch, including pea gravel, pebbles, crushed stone, river rock, marble, lava rock and more.


Stones used for mulch are usually smaller and are well-suited for foundation plants. Decorative rock provides excellent weed control and does not need to be replaced unless the layers settle after a few years.

        • Rubber is great for playgrounds and walking trails as it provides soil protection and offers a nice
          activity bounce.
        • Pine straw and wheat straw are great for helping control soil erosion on slopes.
        • Do not use stone around acid-loving plants as it may add alkalinity to soil.
        • Stone mulch reflects heat in summer, so locate plants accordingly.

Application and Transport


The easiest way to apply mulch is by purchasing bagged mulch. It is much easier to apply mulch by carrying a bag to the area where it is needed, opening it and pouring the contents onto the ground than dealing with a pile of mulch dumped in your driveway, and then having to shovel it into a wheelbarrow and physically moving it around the yard.


Using bagged mulch will also save you a lot of time. You’ll shave hours off your mulch maintenance using bags. You can also fit up to 30 bags in most SUVs and mini-vans with the back seats folded down.


A standard bag covers approximately 6 square feet to a depth of 2 inches. Spread it around your plants evenly and make sure you keep it away from plants stems and tree roots to ensure best results.


You can also use mulch in open areas, gardens, flowerbeds, playgrounds and on slopes for erosion control. Always wear gloves and old clothes when applying mulch.


To learn more about how to apply different types of mulch for maximum effectiveness, consult the following chart.


Mulch Type

Application Tips

Bark and Shredded Hardwood • Apply 2 to 4 inches of bark mulch around plants
• Keep mulch an inch or two away from tree trunks
Pine Needles • Work well for acid-loving shrubs, trees and plants, such as azaleas, camellias and
• Are attractive, especially for wooded lots, but may not be available in all areas of
  the U.S.
Decorative stone • Mark off the area you intend to fill, then line with edging material to form a border
• Remove unwanted vegetation
• Rake area to achieve a smooth, even surface
• Spray the area with weed killer and lay in a layer of landscape fabric to discourage
  weed growth
• Top with decorative stone
Leaves • Chop leaves with lawnmower or shredder before spreading
• Spread 3 to 4 inches of damp leaves or 6 inches of dry leaves
• Add more layers as leaves decompose
• Do not stack leaves tight against plant stems
Rubber • Ideal for playgrounds and safe for use around plants
• Deters insects and termites while preventing weeds

Mulch Alternatives


Black Plastic: Black polyethylene plastic is effective at preventing weed growth, though it tends to hold water in the soil. Some black plastic is sold with tiny holes to facilitate drainage. Exposed to sun, black plastic can degrade and lose its effectiveness, which is why some gardeners bury it in the soil. Black plastic acts as a good underlayment for organic or rock mulch.

Landscape Fabric: Landscape fabric is sold in a range of widths and lengths and is specially treated to resist rotting. Unlike plastic, landscape fabric is porous and allows water, air and nutrients to pass through. Weeds sometimes poke through, but overall, fabric is effective at weed control. Better weed control can be achieved by adding more mulch on top of the fabric. Many gardeners add decorative wood or stone mulch on top of fabric to enhance its appearance. Landscape fabric works best for shrubs and non-spreading plants.  


Grass Clippings: Grass clippings are an excellent way to repurpose the leftovers after mowing the lawn. They can be replenished as frequently as you mow the lawn but will only be available throughout the summer months. You can add the clippings to your garden soil to help boost nutrients.


Manure: This is an excellent way to repurpose the natural by-product of cows, horses, goats and other farm animals. Be sure the manure is well-rotted before applying in gardens.


Newspaper:  This is a readily available landscaping aid that can be used under mulch. Ensure the newspaper does not touch the plant stem to allow room for the plant to grow, and do not use colored pages as the ink may harm the soil and plants.