About Mulching

About Mulching

Mulching can be one of the most beneficial things you can do for your soil and your plants. If you have not considered mulching your landscape in the past, you may want to reconsider.

Mulches provide a huge labor savings for gardeners and landscapers alike. A layer of mulch will help prevent the germination of many weed seeds, reducing the need for cultivation or the use of herbicides. Mulches also help moderate the soil temperature and retain moisture during dry weather, reducing the need for watering. Mulches protect the soil from the impact of raindrops that can cause crusting. Crusting can prevent the germination of seedlings.

While there are many types of mulch, WM EarthCare™ focuses on organic mulches produced from 100% recycled, locally sourced, clean wood materials. Our mulches help improve the soil by adding organic matter as they decompose. They also may encourage the growth of worms and other beneficial soil organisms that can help improve soil structure and the availability of nutrients for plants.

Mulches also can be used to enhance the look of your landscape. WM EarthCare™ recycled wood mulches are available in a variety of colors that can be used to contrast with landscape plant materials. The mulch helps keep plants clean by reducing the splash of soil onto leaves during rainstorms, and helps infiltration of the rainfall into the garden.


Benefits of Mulch

  • Protects the soil from erosion
  • Reduces compaction from the impact of heavy rains
  • Conserves moisture, reducing the need for frequent irrigation
  • Maintains a more even soil temperature
  • Prevents weed growth
  • Keeps fruits and vegetables clean
  • Keeps feet clean, allowing access to garden even when damp
  • Provides a “finished” look to the garden


When to Apply Mulch

Time of application depends on what you hope to achieve by mulching. Mulches, by providing an insulating barrier between the soil and the air, moderate the soil temperature. This means that a mulched soil in the summer will be cooler than an adjacent unmulched soil; while in the winter, the mulched soil may not freeze. However, since mulch acts as an insulating layer, mulched soils tend to warm up more slowly in the spring and cool down more slowly in the fall than unmulched soils.

If you are using mulches in your vegetable garden or flower garden, it is best to apply them after the soil has warmed up in the spring. Cool, wet soils tend to slow seed germination and increase the decay of seeds and seedlings.

If adding additional layers of mulch to existing perennial beds, wait until the soil has warmed completely.

Mulch used to help moderate winter temperatures can be applied late in the fall. Mulch used to protect plants over winter should be kept loose to help insulate the plants without compacting under the weight the material. One of the benefits from winter applications of mulch is the reduction in the frost damage often experienced in the late winter and early spring.


Applying Mulch

Begin by asking yourself the following questions:

1. What do I hope to achieve by mulching?

  • Weed control?
  • Moisture retention?
  • Soil improvement?
  • Beautification?

2. How large is the area to be mulched?
3. How much mulch will I need to cover the area? Mulch is measured in cubic feet. As an example, if you have an area 10 feet by 10 feet and you wish to apply 3″ of mulch, you would need 25 cubic feet. (Mulch Calculator)


Determine what mulch material to use and purchase what you need:

Vegetable Gardens and Raised Beds
Apply a 2 – 4″ layer (after settling) of mulch to prevent weed seeds from germinating. Mulch should be applied to a weed-free soil surface. For beds, mulch the entire area. The best time to mulch is late spring after the soil has warmed. It is not necessary to remove the mulch when you fertilize.

Trees, Shrubs and Landscapes
Apply a 2 – 4″ layer (after settling) of mulch to prevent weed seeds from germinating. Mulch should be applied to a weed-free soil surface. For beds mulch the entire area. For trees, apply mulch in a circle covering the entire root system of a tree that often extends well beyond the tree canopy. Keep mulch at least 6″ from the base of the tree trunk. The best time to mulch is late spring after the soil has warmed. It is not necessary to remove the mulch when you fertilize.

General Guidelines
Do not apply mulch directly in contact with plants. Leave an inch or so of space next to plants to help prevent diseases flourishing from excessive humidity. Remove weeds before spreading mulch.


WM EarthCare™ Landscape Materials

Compost3″–4″May be applied directly to the soil surface as mulch, or mixed with soil to a depth of 6″– 8″ as a soil amendment. Planting in 100% compost is not recommended. Excellent for enriching soil. May be applied throughout the year.

Product Amount to Apply Notes
Wood Mulch 2″–4″ Excellent for use around trees, shrubs, and perennial gardens – either dyed or natural. When spreading mulch around trees, keep the mulch 6″ away from the trunk. Taper the depth of mulch away from plantings. Natural dye is safe animals and children and colorfast. Color will not fade for one year. Best applied in fall or in spring after soil warms.
Aggregate 2″–3″ Thicker layers tend to compact reducing drainage. Apply over 4″ sand base with geotextile material. Excellent in areas where the possibility of fire may be a concern.


Mulch is sometimes used with landscape fabric or plastic. The fabric or plastic is laid on top of the soil and then covered with a layer of mulch. A caution to this practice: while initially the plastic or fabric may provide additional protection against weeds, as the mulch breaks down, weeds will start to grow in the mulch itself. The barrier between the soil and the mulch also prevents any improvement in the soil condition and makes planting additional plants more difficult.