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How to Make Sandy Loam Soil

By Robin Lewis ; Updated September 21, 2017
Healthy soil makes healthy plants
The old wheelbarrow image by Shirley Hirst from Fotolia.com

Sandy loam soil is a very desirable soil when planting garden plants. Sandy loam has a light, airy texture and a rich, medium-dark color. The texture of sandy loam allows oxygen to reach the roots of the plants, where it can be put to good use. The sand allows adequate drainage, while the loam retains moisture for plants to use later. By testing her soil and making some amendments, the average gardener can make her own sandy loam to improve the health of her garden.

Test the soil to determine its characteristics using the jar method. Place 1 inch of soil into a clear quart-sized jar and fill the jar about two-thirds with clean water. Shake the jar for one minute, then place it on a flat surface. The jar must remain in the same spot for two days without being moved.

Mark the levels of sediment that have formed, using a permanent marker, after one minute, then after four hours. Mark the final soil height after two days. The bottom layer is the sand layer, the second layer is the silt and the third layer is the clay.

Measure the distances between each layer and the overall height of the soil. This will help you determine the percentage of each component; sand, silt and clay. This is necessary to know before amending the soil as it provides the starting point.

Shovel the soil that will be used into 1-gallon containers to measure the amount being used, then pour it into a wheelbarrow or large container for mixing. Be sure to remove any debris, rocks or roots from the soil and break up any large clumps before measuring.

Determine how much sand and organic matter you will need--based on your soil test--to add to your soil to produce sandy loam. Sandy loam is made up of 50 to 70 percent sand, less than 20 percent clay, and 10 to 50 percent silt or organic matter. So if you have 20 percent sand in your existing soil, you will need to add enough sand to make it at least 50 percent. If you have 40 percent clay, you will need to add enough of the sand or compost to bring that percentage down.

Mix the soil thoroughly with your hands, a shovel or a garden rake until all of the new soil amendments are distributed evenly into the old soil.

Perform another jar test on the new soil to be sure that it is composed of the correct amounts of each component.


Things You Will Need

  • Current soil sample
  • 1 quart clear jar with tight fitting lid
  • Clean water
  • Marker
  • Ruler
  • 1-gallon containers
  • Wheelbarrow or large container
  • Top soil
  • Organic matter (compost)
  • Fine to medium grain sand

About the Author


Robin Lewis is a freelance artist, designer and writer. Her articles have appeared in newspapers, national magazines and on several self-help areas of the Web. Lewis specializes in gardening articles, publishing frequently on a variety of websites.