Information archive — soil / compost / mulch

We don’t call that brown stuff on the ground dirt. In recent years we have come to understand how that soil is very much alive.

Soil is the single most important thing to get right in your garden or landscape.

It is very difficult to meaningfully change the composition of residential house lot soil. Instead, we recommend incorporating a significant amount of compost and/or appropriate soil conditioner into the soil, then topping it with a thick layer of woody mulch. Improving the soil (and maintaining its health) is different for lawn than for ornamental garden beds. Learn more about the various aspects of soil below.

Below are some invaluable resources to help in your quest to make and maintain good soil.

• Home Gardeners Guide to Soils & Fertilizers — WSU Extension.

  This is what is taught to the Master Gardeners. Pretty much everything you need to know about soil, nitrogen cycle, fertilizers.

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  Nitrogen in Garden Soils — NBB program.

  Handy information about what type of nitrogen plants need and when they need it.

• Nutrient Cycling (or nitrogen cycle)

  This is a term used to describe the process of how organic matter is cycled and recycled through an ecosystem. One of the ways nutrients is recycled is by breaking down fall leaves. We feel using one’s fall leaves is the most low-cost and low-maintenance way of supplying mulch and nutrients to your ornamental landscape.

  • Using Leaves as Mulch — How fall leaves can improve ornamental landscape beds. Flyer companion to voice recording.

• Soil Food Web

  Feed the soil and it will feed your plants. Learn how the soil food web works and how you can help it thrive.

  • Soil Food Web — by Elaine R. Ingham for the United States Department of Agriculture
  • Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web — by Lowenfels, Jeff & Lewis, Wayne. Timber Press 2010.
    

    Just about the best, most typical-gardener-friendly explanation of how soil works. We consider this a ‘must read’ book. We like that it has an organic leaning. The link is to Amazon.com, but this book is also at the library.

  Lowenfels has authored other books about the soil including:

  • Teaming with Nutrients: The Organic Gardener’s Guide to Optimizing Plant Nutrition
  • Teaming with Fungi: The Organic Grower’s Guide to Mycorrhizae

• Soil Testing

  • Organic Farming Systems and Nutrient Management: Soils and Soil Testing — Washington State University
    

    Resources from how to take a sample of soil to how to interpret analysis results.

• Soil Types

  • Soil Types: What are the differences? — SFGate HomeGuides.

In ornamental gardens in our region, compost should always be covered by mulch. Compost is a medium that has nutrients released for absorption by plant roots. If it is left uncovered, it will grow weeds! One of the functions of mulch is to help prevent weeds. Compost should not be used for weed prevention. If you have an established ornamental garden, you may not ever need to apply compost if you maintain proper mulch coverage. If you are creating a new garden or rehabilitating a worn out one, you can either incorporate compost into the soil’s upper layer, or you can simply put a layer of compost on top of the soil; then apply a layer of woody mulch.

These resources will help you understand what compost is, how it works, and basics principles you need to know about composting to help you get started.

• Buying Compost? Read this first

  Dos and don’ts when buying compost.

• Composting at Home

  • Composting at Home — Master Composter/Recycler program.
    Brochure.
  • Composting at Home — Master Composter/Recycler program section of Clark Green Neighbors website.
  • Composting at Home - Evironmental Protection Agency

• Composting Horse Manure — If you have horses, read this.

• Crimson Clover Cover Crop

  • Crimson Clover Cover Crop — This very common agriculture cover crop is very useful in the ornamental garden and readying any poor site for any type of gardening endeavor. Article contains how-to and resource links.
  • Crimson Clover - Improving Cover Crops — Oregon State University & Oregon Clover Commission.

• Let It Rot! — by Stu Campbell.

  This book is also available at the library!

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  Making & Using Compost — University of Missouri Extension

  One of the best online guides we have found. 

• The Rodale Book of Composting

  Rodale is a trusted name in organic gardening. You can also find this book at the library!

In ornamental gardens in our region, mulch should always cover both bare soil and compost. Mulch helps the soil in ornamental gardens by: moderating temperature, retaining moisture, providing nutrients as it slowly composts in place, and preventing weeds.

Mulch can be a variety of materials, but we recommend high-carbon, un-composted, woody material. In our area, tree bark is most commonly used. But the NBB program advocates using fall leaves as mulch. And why not? They fall from trees into the garden requiring minimal-to-no cost or work in accomplishing the task of mulching. Leaves (and other woody debris) are pretty much what a natural forest uses for mulch, and that system has worked well for millennia. Why not borrow from what works?

We also like use of arborist chips as mulch.

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  How Plants & Mulch Prevent Erosion — Video by Fun Science Demos.

• Proper Mulching — International Society of Arborculture (ISA).

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  Mulch, Mulch, Mulch — Goodnight Design.

  The logic of using fall leaves as mulch in the ornamental garden.

• Nutrient Cycling (or nitrogen cycle)

  This is a term used to describe the process of how organic matter is cycled and recycled through an ecosystem. One of the ways nutrients is recycled is by breaking down fall leaves. Using fall leaves is the most low-cost and low-maintenance way of supplying mulch and nutrients to your ornamental landscape.

  • Using Leaves as Mulch — How fall leaves can improve ornamental landscape beds.

• Wood Chips as Mulch

  Check out chipdrop.in. Arborists use this website to check to see if anyone near their project is registered to accept a free delivery of chips. It is a great deal, but you should be aware that they cannot give you an exact time/date when they will make their delivery, you do not get a choice what type of tree wood you will get, and you do not know the quantity you will get.

  Read Dr. Linda Chalker-Scott’s paper on wood chips below to learn why we like them so much.

  • Wood Chip Mulch — WSU Extension, Puyallup.

    This is one of Dr. Linda Chalker-Scott’s excellent fact sheets.

Erosion can be a problem in any landscape even if there isn’t much slope. There are various types of erosion, but in the video below, they are talking about how the flow of water over or through the soil can cause erosion.

But as good as mulch is at preventing erosion, it isn’t as good as a dense planting of live plants. This video shows how much cleaner the planted soil water overflow is than without plants or mulch.

• Also see Plant Lists for appropriate plants to prevent erosion; the stormwater management section of Water Use & Management for strategies of managing stormwater.