Guide to Soil Characteristics

It is important that you understand the soil characteristics of your garden if you want to make the most of your planting endeavors.

| June 2014

a jar of soil

This soil is approximately 45 percent sand, 5 percent silt and 50 percent clay. Organic matter is negligible.

Photo courtesy PALS Publishing

Have you ever hesitated before planting, unsure whether your garden plan is right for the space you have to use? If that’s the case, you need to check out Site Assessment for Better Gardens and Landscapes (PALS Publishing, 2013), a great tool for learning how to evaluate the characteristics of a site and determining which plants will thrive. Author Charles P. Mazza offers advice and strategies for gardeners novice and expert alike, with more than thirty hands-on activities and fifty color photos. This excerpt comes explains how to determine the soil characteristics of your site, and how that affects your selection of plants.

You can purchase this book from Capper's Farmer store: Site Assessment for Better Gardens and Landscapes.

Why is Knowing Soil Characteristics Important?

Soil can make or break a garden or landscape because it supplies water and nutrients to plants through the plants’ roots. Too much or too little of either can hurt plant health. The physical and chemical composition of soil varies from place to place and can even be different within the same yard. Considering soil characteristics will help you select plants that will thrive.

The physical composition of soil is determined by the soil’s texture — the relative amounts of sand, silt, and clay in the soil. Knowing the soil’s physical composition will help you make informed decisions later in the process. The chemical composition of the soil — the levels of nutrients present and the soil pH — affects nutrient uptake by plants. For example, some plants (such as blueberries and rhododendrons) require acidic soil.


1. What’s the physical composition of my soil? — Soil Sedimentation Test

• Pointed shovel
• Bucket
• Sealable plastic bag
• Pint-sized glass jar with tightly fitting lid — the narrower the better (an olive jar works well)
• Kitchen timer, watch, or electronic timer
• Powdered dishwasher detergent
• Ruler
• Masking tape
• Site assessment notebook 

Estimated Time: 20 minutes of collecting, observing, and recording. Overnight for drying the soil. It may take 2–3 days to complete the test.

9/9/2014 11:57:20 AM

Very interesting article. I have a question about the effect of water on soil. We live in an area with very clay soil. It is so fine in particle that when you dig a hole (with great effort) water will sit in the hole for days and won't percolate down. So we built beds and brought in soil because we wanted to plant right away. However, doing a water test revealed that our well water was very alkaline. This is also evidenced by the fact that calcium carbonate deposits remain when water goes down in the local creeks. We also have very hot weather (often in the triple digits for days at a time). My vegetables don't flower well, have high percentage of male to female flowers. My yields are very low. I can grow sweet basil and sunflowers like gangbusters. Is my water ruining the pH in my boughten soil?

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