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Soil Tests and Amendments

When it’s nearly time to plant, you’ll want to prepare your garden soil. If your soil needs help, here are some tips on testing soil, soil fixes and soil amendments.

For optimal plant growth, soil must have the proper pH level. pH is measured on a scale of 1 to 14. A measurement of 7.0 is neutral. A number below 7 is acidic (sour) and above 7 is alkaline (sweet). Soil pH signifies a plant’s ability to draw nutrients from the soil.A soil test will enable you to determine whether your soil is neutral, alkaline or acidic so you can adjust the soil to the appropriate pH level. Most plants prefer nearly neutral soil with a pH between 6.2 and 7.2. To achieve this goal, acidic soil may require the application of lime. Alkaline soil may require some sulfur.

Testing your soil allows you to: 1. Select the right plants for your garden. A pH test, for example, shows the acidity / alkalinity of your soil. You can then pick plants that will survive and thrive in your soil conditions .2. Remedy your soil problems. Determine what key elements are missing from your soil. 3. Monitor nutrients. Nitrogen, phosphorous and potassium are needed for plant growth, color and blooming.

Quick General Soil PH Tests

Scoop some soil into a container. Then, add a half-cup of vinegar. If the soil bubbles or fizzes, it’s alkaline. If there’s no reaction, scoop a fresh soil sample into a second container. Add a half-cup of water and mix. Then, add a half-cup of baking soda. If the soil bubbles or fizzes the soil is highly acidic. Amend your soil with wood ash or lime, if it’s acidic. Amend your soil with sulfur or pine needles, if it’s alkaline.

Quick General Soil Type Test

  • Place 5 inches(or 5 cm) of soil into the jar and add a tablespoon of powdered dishwashing detergent. The detergent is a surfactant, which keeps the soil particles separate, resulting in a more accurate test.
  • Fill the jar to the top with water, screw the lid on, and shake the jar for three minutes to thoroughly combine the soap, soil, and water, and to make sure no soil is stuck to the bottom or sides of the jar.
  • Set the jar somewhere stable & out of the way to let the sediment settle.
  • As the sedimentation progresses, check the sample periodically to watch the layers form and to note the size of the particles settling out.

If you have more than one sample, label or identify your jars on a piece of tape on a mason jar so you can keep things straight. What part of your land did they come from? Surface samples, or from depth?


First, what type of soil do you have? Remember: soil is more than dirt! You can’t just throw down seeds and expect plants to grow.

Soil needs to be nutrient-rich, to enable your plants to absorb moisture, anchor roots and grow up strong.

To find out your soil type, you need to test your soil. Contact your local cooperative extension office for a free (or low-fee) soil test. You can see the main usu soil testing site or calling the local office at (435) 586-8132.

For most soil, you can start by simply mixing in compost. However, your soil test may indicate that your soil needs more of a helping hand.


  • If you have clay soil, add coarse sand (not beach sand), compost, and peat moss.
  • If you have sandy soil, add humus or aged manure, peat moss or sawdust with some extra nitrogen. Heavy, clay-rich soil can also be added to improve the soil.
  • If you have silt soil, add coarse sand (not beach sand) or gravel and compost, or well rotted horse manure mixed with fresh straw.


  • Bark, ground: made from various tree barks. Improves soil structure.
  • Compost: excellent conditioner.
  • Leaf mold: decomposed leaves that add nutrients and structure to soil.
  • Lime: raises the pH of acid soil and helps loosen clay soil.
  • Manure: best if composted. Good conditioner.
  • Peat Moss: conditioner that helps soil retain water.
  • Sand: improves drainage in clay soil.
  • Topsoil: usually used with another amendment. Replaces existing soil.


The next step is to add fertilizer. Nitrogen (N) is needed for leaf growth and is responsible for making plants greener. Phosphorus (P) is associated with root growth and fruit production. Potassium (K) also known as potash, helps the plant fight off diseases and keeps it vigorous.

Fertilizers are labeled to show the percentages by weight of the fertilizer. A 100 –pound bag of 10-5-10 contains 10 pounds of nitrogen, 5 pounds of phosphorus, and 10 pounds of potassium. The rest is filler, which gives it bulk and make it easier to spread.
(Information from The Old Farmer’s Almanac at