mulch matters

Why Mulch Matters

By Shelly Montgomery, Master Gardener In Carpenter, Wyoming

Home gardeners spend a significant amount of time fighting weeds. Here in the Rocky Mountain West we also face prolonged dry weather, hot sun, and often dense soils.

Many gardeners consider mulch essential for trees, rosebushes, and landscaping projects but its use in the vegetable garden may be undervalued.

Using mulch can help regulate soil temperatures, increase moisture retention, and decrease weed seed germination. In hot, humid regions mulch can present challenges with mildew and rot by retaining too much moisture, but that is generally not a problem in the Rocky Mountain West.

Mulch is classified as organic or inorganic. Organic mulches are made from once-living items such as grass clippings, compost, straw, and bark. Inorganic mulches include man-made or mined materials like shredded paper, landscape fabric, cardboard, and gravel.

You can apply layers of mulch to your soil after your seeds have started to grow true leaves or when you transplant starter plants into your garden. As your plants grow stronger, continue to layer mulch for maximum benefits.

Different types of mulch provide different benefits for your soil.

Organic Mulch

Bark and wood chips

Bark and wood chips are readily available to most home gardeners. These mulching materials can be made at home by using a wood chipper or purchased ready-to-use.

One advantage of bark and wood chips is that they break down slowly and don’t blow away easily in wind-prone areas. The cedar oil in mulch made from cedar bark is also a natural insect repellent.

Murdoch’s Ranch & Home Supply stocks several different varieties of bark and wood chip mulch:

Grass Clippings

Grass clippings are a great addition to your garden in conservative amounts. A light layer applied each time you mow your lawn will add a natural source of nitrogen to your garden and recycle your lawn waste.

Use caution if you use pesticides or chemical fertilizers on your lawn. You may want consider whether or not you want chemical fertilizers in your garden. Residuals of chemical pesticides on your grass clippings may harm the good bugs in your growing space, as well as the bad.

If you are mowing prairie or natural areas, consider whether or not your clippings may contain weed seeds. If so, you may be causing more challenges for yourself down the road.

All types of grass clippings can be properly composted if there is a good reason not to add them directly to your garden.


Compost can be an excellent mulch. It will add beneficial nutrients and moisture-retaining properties to your garden beds. Do not use fresh animal manures in vegetable and herb gardens as they may contain bacteria that are harmful for you and your plants. Fresh manures should be properly composted before being used as a mulch.

Good compost tends to be lighter than bark or wood chips and may blow away on windy days. One way to prevent this is to cover a layer of compost mulch with a layer of heavier mulch such as cardboard, wood chips, or gravel.

Several different types of ready-to-use mulch are available at your local Murdoch’s Ranch & Home Supply:

  • Coop Poop – Composted chicken manure. OMRI listed.
  • Black Gold Garden Compost – Contains compost, bark, and peat moss. OMRI listed.
  • Yard Care Composted Sheep Manure - Sheep manure mixed with ponderosa pine and Douglas red fir bark. Great for sandy and clay soils.
  • Mountain Magic Natural Mountain Compost – Aids in moisture retention and adds valuable nutrients to the soil.


Straw is a valuable mulch especially in the often arid and dry Rocky Mountain West. It is important to choose weed-free straw, or before long, the weeds your mulch was meant to prevent will be sprouting heartily.

One disadvantage to straw is that it breaks down more quickly than some of the heavier mulches and may be more prone to blowing away. Leaving straw in “flakes” or sections of the bale will create a mat-like surface that decreases the likelihood of losing your mulch.

Potatoes grow especially well in straw mulch. Plant your seed potato in just the first few inches of soil. As the plant grows continue to add straw. Eventually, you will be able to pull-back the straw and harvest new potatoes from the plant while leaving some potatoes to go on and grow to full size. This also eliminates deep digging at harvest time!

Inorganic Mulch

Shredded Paper

Shredded office paper and newspaper can be used as an effective and inexpensive mulch. Some gardeners even claim that the reflection of the sun off the white paper helps heat-loving plants like peppers grow better in the cooler climates of our region.

In the past, there was concern that paper contained toxic chemicals like lead in the ink. Lead is no longer used and most inks are soy-based and do not cause problems in the home garden.


Cardboard can be a great way to prepare a new area for tilling. Placing large pieces of cardboard over grass will prevent growth and allow the turf to break-down.

Cardboard can also be used between plants and on garden paths to prevent weed growth. In wind-prone areas, weights such as rocks, gravel, or landscaping pins should be used to hold the cardboard in place.

Gravel, while expensive, is one of the most effective mulches for our region. It does not break down or blow away and adds more permanent protection to the garden.

One disadvantage is that it does not add nutrient value to the soil and cannot be turned back into the soil at the end of the season like more organic mulches.

Pea gravel is readily available at Murdoch’s Ranch & Home Supply:

Landscape Fabric

Landscape fabric is one of the gardener’s best friends. It retains moisture, repels weed growth, limits garden pests, and increases soil heat. Rain and irrigation water can soak through it while providing a barrier to weeds attempting to grow from below.

Landscape fabric is placed after your garden bed is prepped for the season with compost and any other amendments. If you are using drip irrigation, place the irrigation under the landscape fabric. Once the fabric is staked in place, simply cut a small X in the fabric and plant your starter.

Since landscape fabric is black it can add heat to your soil. This is great at high-altitudes where cool nights can slow growth but can be a problem if the summer gets too hot. In order to cool the soil, use a different mulch such as gravel, bark, or straw on top of the fabric.

The fabric can be removed at the end of the season and re-used for many years.

Murdoch’s Ranch & Home Supply has landscape fabric available for the home gardener:

Why Mulch Matters

Mulch encourages beneficial microbial life in your soil and will increase earthworms and other beneficial fauna in your garden. There is nothing more satisfying than pulling back layers of mulch to see the soil below teeming with life.

Mulch matters because it makes your life easier and your garden healthier. There several options for every growing environment. If you are tired of fighting weeds and your garden drying out when the season gets hot, it is time to layer on some mulch!

Related Articles

spreading seed

Farm & Ranch

How to Spread Pasture Seed

There is no one recipe to follow when it comes to pasture seeding. It’s as unique as the land you’re working...

Read More

Choosing the right soil

Lawn & Garden

Choosing the Right Soil

Dig-in to soil science and discover the recipe for getting more from your cultivating efforts – indoors and out!

Read More

testing soil ph

Lawn & Garden

Testing Soil pH

Does the composition of your soil meet the needs of your garden plants? A good way to find out is to test a soil’s pH level.

Read More