The most important thing we can do for our yards and gardens is to provide healthy soil. Healthy soil produces healthy plants. No matter what type of soil is in place when you acquire your yard, it can be made better with the addition of compost and/or mulch. If your funds are limited, good quality mulch is the best investment you can make in your backyard.
Soil contains billions of micro-organisms that eat rotting organic matter and transform it into nutrients available for plants. Compost and mulch figure heavily into feeding the soil biota. Compost may be incorporated into the soil to immediately start feeding the soil life. Mulch should be used on top of the soil and/or compost. Over time, mulch turns into compost on its own.
How to build good soil:
Understand Soil Types
Soil has many components, and it is generally broken down into three types: Clay, silt, and sand. Clay has the smallest size, Because of this, it packs together densely which limits how much air is contained within the soil. Sand has the largest particle size. Because of this, it has very large spaces. This is great for air flow, but it also means that water flows out of it very easily. Silt sits somewhere between the extremes of clay and sand.
Generally, a blend of the three soil components is deemed the best for most gardening needs. This pleasant blend is called loam, and in Clark County, it is very difficult to find. We have more than our fair share of hard, dense clay soils. You don't need to try to make loam out of raw ingredients. If you have mostly clay or sand soil, add compost to your soil.
You can make your own compost from the yard debris created in your own backyard. The Clark County Master Composter/Recycler Program is an excellent source of information. Through their workshops you can get started on your own compost pile. The Master Composters can also recommend composting demonstration sites so you can see firsthand how the compost cycle works.
We understand that not everyone has the space for (or their neighborhood association may not allow) composting. What to do? You may be able to get compost from or a friend, but you can also buy compost.
Even if you don’t have a garden in need of it, composting is a good way to keep kitchen waste and other organic materials out of the landfill. Here are some things you can do with unwanted/unneeded compost. We encourage everyone to compost.
Mulch is an under-used and under-rated commodity in the garden environment. 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 Naturally Beautiful Backyards 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 the same materials a natural forest uses for mulch, and that system has worked well for millennia.
An added benefit of mulch is that it eventually turns into compost all on its own, thus providing food for the soil biota.
Recently we have seen arborist wood chips used as mulch. This is a great way to recycle arborist leftovers. Learn more about wood chips, where to get them, and how to use them in the Information Archive.
The benefits of mulch far outweigh their simplicity in the garden. The addition of three inches of mulch in the spring around early vegetables provides shelter from freezing temperatures. Mulch in perennial and garden beds deters weeds, increases moisture retention, and stabilizes soil temperatures during extreme hot or cold spells. Mulching garden beds before the winter rains provides protection of garden soil from compaction and provides an available nutrient source to turn into the bed in spring. Three inches of mulch applied in the spring before weed seeds have matured will save hours of weeding in the summer months.
Some guidelines for using mulch:
- Mulch depth can vary between 3"–6" for most ornamental garden needs. Finely textured mulch can be toward the lower end of that range. Coarse, arborist chip mulch can be toward the higher end. Less than 3" depth doesn't supply adequate weed suppression.
- Apply mulch any time of the year when soil or compost can be seen through the mulch, or any time the mulch depth is less than listed above.
- Before applying mulch, either new or refreshing old, make sure the soil below is well-watered. Mulch is an insulator, and if the soil below it is dry, the mulch will keep it dry until a very large quantity and duration of rain occurs.
- Keep mulch away from woody-plant root crowns to avoid damage from pests and disease.
- Gravel and other inorganic materials are not good mulches for gardens/landscapes. These things ARE good for creating walkways, patios and other hardscape features. In most cases, use a weed barrier between the inorganic material and the soil.
- Organic mulches decompose and need to be replaced. Replacement is based on the type of mulch used: fall leaves last about a year; 3–4" of bark typically last two to three years; 5–6" of arborist chips may last three to four years.
Learn About the Soil Food Web
The soil food web is a complex collection of living organisms in the soil that work together to create healthy soil. It is a lot more complex than that, and you can learn more by reading Teaming with Microbes: The Organic Gardener's Guide to the Soil Food Web by Jeff Lowenfels and Wayne Lewis.
Nutrient cycling is the process organic matter cycled from living to non-living and back to new living matter through an ecosystem and is regulated by the soil food web.
Explore the entire Information Archive