Mulch


Although all of the 7 basic principles of gardening are important and will greatly enhance your gardening success, the easiest to implement is to use mulch.

Mulch is material placed over the soil – beds, borders, vegetable gardens, even lawns -- that help preserve moisture, improve soil structure and quality, and moderate temperature.

 

Use Mulch Appropriate to the Plants

An example most of us can readily relate to in understanding mulching by natural means is that of the leaf and plant litter on the forest floor. It is easy to witness the buildup of organic mulch with even one pine tree. Needles, bark and twigs are shed throughout the year, layering the soil. Leaves from surrounding trees blow in too. The bottom most mulch material slowly decomposes as new mulch is slowly added. Walking is softer, almost springy in some cases. Earthworms, an indicator of healthy soil, will be present in soil mulched over for a number of years and are closer to the surface. If you ever have the opportunity to dig in a wooded area, and then in an area adjacent to it not wooded or mulched, you will certainly experience the difference in soil textures.

The shortgrass prairie’s manifestation of natural mulching isn’t as apparent. Trees and forests are in short supply. But our abundant wide-open plains nurtures short grasses and forbs that follow a similar cycle of the seasons. Autumn’s spent leaves provide groundcover for soil, seeds and wildlife throughout the cold winter months, giving way in springtime to new growth. Eventually, yesteryear’s prairie decays, building and replenishing the soil, though at a much slower rate. When rangeland is spared over-grazing, our prairie’s natural mulch is more apparent, just not as spongy and moist as the forest floor.

Plants that thrive in the shortgrass prairie community are tolerant of their climate and conditions. The constant struggle between fire, wind and hail, the cloudless blazing sky, blizzard, cloudburst and drought, hardened and toughened our steadfast prairie stalwarts. The thin layers of vegetative debris or rock, stone and gravel cover provide ample mulch for shortgrass prairie survivors. Plants and animals, soil and climate conditions coexist in an ecology developed over the ages. To garden more naturally within the scope of our environment, and with less maintenance, look to nature and mimic her conditions and solutions.

Different ecosystems or biomes accumulate different mulches. Botanical gardens across the United States, and no doubt the world, use mulch found in the plant’s natural habitat. In creating these display gardens, they seek to use mulch that denote a sense of place, not looking “out of place”. Some botanic gardens, such as the Denver Botanic Gardens, do not even use organic mulches for plants native to the western United States: “ ‘We don’t use any organic mulches unless you count top dressing, which is applying several inches of compost to perennial beds and shade gardens,’ ” according to Rob Proctor, DBG’s artistic director. “Even the use of compost as a top dressing and soil amendment is limited to shade plants that are not native to the region. ‘Putting an organic mulch, such as bark, on other types of beds,’ Proctor explains, ‘is completely unnatural for this region.’ Taking further cues from nature, Proctor adds, ‘we do use inorganic mulches, specifically pea gravel, in areas where we have rock garden plants or native western plants that evolved in stony soil.’ ” (“Smart Mulching”, by Rita Pelczar, The American Gardener Magazine, January/February, 2003.)

All bare ground in your landscape should be mulched. Mulches can be organic or inorganic. Different mulches are used for different purposes; use the most appropriate mulch for your plant type or purpose. Our home landscapes have many different micro-niches in which we use plants best suited for them. Some mulch is more useful for covering beds, borders or vegetable gardens, while other types of mulch are more suited for paths and walkways.

For medium and high water use areas (where plants from ecosystems and regions other than our own) benefit more from organic mulches. By far, compost is the best mulch to use, but there are others you may select. More than one type material is found naturally covering the ground in a forested area. Avoid scrupulous bed and border cleanups. Mulch cover and plant debris from the plants themselves provides habitat in a healthy ecology. Leave mulch material to protect the soil, plant and beneficial animal life, both micro and macro organisms.

 

Overview of this Basic Principle of Gardening – Using Mulch

Organic mulches are straw, grass clippings and healthy chopped plant debris, shredded bark, wood and bark chips, pine needles, compost, humus, cottonseed hulls, cocoa bean hulls, pecan shells, peanut hulls, chopped and crushed corncobs, mushroom compost, shredded newspapers or other papers (depending on ink used), leaf mold, chopped leaves, and living plants. If you're an impatient composter, "almost compost" makes excellent mulch.

Some inorganic mulches are crushed gravel and granite, small stone, lava or granite rock, decorative and colored stones, sand, plastic, or crushed brick and crushed, tumbled glass.

In this principle on using mulch, I describe the benefits of mulch, the different types of mulch to use, both organic and inorganic, mulch tips and uses, mulch insights and cautions, mulch and extending cold hardiness, how mulch helps to conserve water and how mulch helps moderate soil conditions and our extremes of climate. As you will learn, there is much, much more to mulch than just wood chips or volcanic rock. If you haven’t used mulch before, I hope you start using mulch and reap all these benefits.

Please read through this entire page on mulch, especially the cautions and insights section under Much More about Mulch and use whatever mulch is most appropriate for your plants and pocketbook.

Angie Hanna, July, 2006

Angie Hanna

Basic Gardening Principles (Xeriscape Principles)

  1. Plan and design
  2. Analyze and amend the soil
  3. Create practical turf areas
  4. Efficient use of water
  5. Choose appropriate plants
  6. Use mulches
  7. Practice appropriate maintenance

Ecologically Friendly

  • Plant best adapted species
  • Plant in preferred season
  • Balance mineral content of soil
  • Build and maintain soil organic content—humus
  • Do not harm beneficial soil life
  • Consider insects and diseases as symptoms of a violation of one of the above guidelines.

Mulch

Mulch is material placed over the soil – beds, borders, vegetable gardens, even lawns -- that help preserve moisture, improve soil structure and quality, and moderate temperature.

Organic Mulches

Compost, composted manures and humus

Leaves and leaf mold

Straw

Grass clippings and other healthy, chopped, plant debris

Shredded bark and bark chips

Pine needles

Wood chips

Buckwheat hulls

Cocoa bean hulls (toxic to dogs)

Cottonseed hulls

Mushroom compost

Pecan and peanut hulls

Chopped corncobs

Shredded newspaper & other papers (depending on the ink)

Coir dust

Living plants

Inorganic Mulch

Crushed gravel

Granite and crushed granite

River rock, small stones & pebbles

Crushed lava rock

Decorative and colored stones

Crushed brick

Crushed, graded and tumbled glass

Landscape fabric

Air and water permeable geo textiles

Plastic and aluminized mulches

Benefits of Mulch

Reduces evaporation.

Retains soil moisture.

Controls weeds, prevents germination.

Moderates temperature.

Protects and increases root zone.

Maintains even soil temperature.

Prevents soil crusting, increases in soak of water and aeration.

Reduces erosion and water runoff.

Prevents soil splashing on leaves during heavy rainfall.

Minimizes soil compaction, promotes better soil structure.

Minimizes cultivation.

Saves the gardener time and money by reducing irrigation, herbicide and pesticide costs.

Ecology friendly by reducing need for herbicides and pesticides.

Enhances the look of the landscape.

Creates a sense of place when using locally natural materials.

Benefits of Organic Mulch

(These benefits are in addition to the above benefits.)

Helps feed beneficial soil life at the surface.

Increases beneficial soil life at the surface.

Slowly increases nutrient content of the soil.

Amarillo Wood Chipping Sites

  • Broadway and Hastings across from Ross Rogers Golf Course
  • Southeast Park
  • Soncy Road and 77th Street

Determine Amount of Bulk Mulch to Buy

Multiply length x width of bed for square footage.

1 cu. yd. provides a 4” cover for 81 sq. ft.

1 cu. yd. provides a 3” cover for 108 sq. ft

1 cu. yd. provides a 2” cover for 162 sq. ft.

1 cu. yd. provides a 1 “ cover for 324 sq. ft.

Determine Amount of Bagged Mulch to Buy

Multiply length x width for square footage

There are 27 cubic feet in a cubic yard.

To cover 1000 sq. ft. to a depth of 3”:

You will need 90 – 3 cu. yd. bags, or

120 – 2 cu. yd. bags.

Mulch Insights/Cautions

Mulch does not reduce already present weed infestations.

Mulch does not eliminate plant disease or reduce insect attack.

Insure mulch is weed and pest free.

Mulch is not a substitute for adding organic matter to the soil.

Do not use materials that have been sprayed or treated with herbicides and/or pesticides.

Do not use wood chips or bark from pressure treated, arsenic or chemical soaked products.

Do not use wood chips with a sour smell.

Don’t mulch too high or pile higher than 6 inches.

Do not mulch right up to the stem, trunk or crown of a plant.

Do not use sawdust in beds or borders except for walks or paths.

Do not let wood chips or bark fall into the planting hole.

Do not mulch with fresh manure; compost it.

Do not use recycled rubber for mulch, do not even compost it.

Do not use wood product mulches next to buildings.

Water Conservation With Mulch

Reduces evaporation

Helps retain soil moisture

Moderates temperature

Prevents soil crusting

Promotes water in soak

Reduces soil compaction

Promotes better drainage in the soil

Minimizes cultivation