Soil Testing Basics

• Soil tests are only as accurate as the sample provided. For the best results, follow the directions on the soil test kit being sure to use only clean tools and containers. Dip in solution of 1 part bleach to 9 parts water to clean and sanitize tools for gathering soil to be tested.
  
  

Nitrogen

• Nitrogen is the "N" of soil testing. It exists in many different forms including as nitrates and nitrites. Good levels of nitrogen in soil boost the green growth of plants. Nitrogen encourages lush leaf growth, bushiness and branching. An absence of nitrogen will show up in small plant size, weak and spindly stems or in extreme cases, yellowed misshapen growth. Nitrogen is easily added with compost or general fertilizers.
  
  

Phosphorous

• Phosphorous, the "P" of garden soil, encourages root growth. Healthy root systems are the basis for healthy plants. With a strong root base, plants are less susceptible to wind damage. They are more drought resistant, and can handle an overabundance of water. Strong root systems create plants that tolerate the different variable extremes of growing conditions.
  
  

Potassium

• Potassium, or the "K" in garden soil nutrients, provides the boost for flower production. This nutrient has the responsibility of encouraging plants to flower, produce fruit and continue to flourish. Low levels result in low crop yields and less than ideal blooming of flowering plants.
  
  

Interpreting Test Results

• The first line of results on a soil test is traditionally pH. This should be close to neutral, or 7. Anything between 6 and 7 is acceptable for the majority of vegetables and flowers. The next three lines will provide the results of N-P-K. Results are usually labeled as very low, low, medium, high, etc. This includes only the nutrients readily available to the plants. More nutrients may exist; they just may be tied up with other chemicals. At the bottom of the results will be recommendations on how to improve your soil. Be sure to also test any problem areas separately. Nutrient levels vary year to year; test annually or every other year to keep your growing top notch. Labs and cooperative extensions keep copies of the results. If you have any questions, call them to discuss your particular results.
  
  

Where to Get Testing

• NPK soil testing is performed at many commercial labs. County agricultural and cooperative extension services offer inexpensive testing options. A lab test will give you more accurate results than the push testers or self-done tests available at garden centers. In a pinch, a self-test is better than no test.
  
  

Read Fertilizer Labels

• Garden center fertilizers are interpreted in the order nitrogen, phosphorous and potassium, or NPK. For spring growth, a high nitrogen fertilizer is usually a safe bet. When planting bulbs or rhizomes, sprinkle some phosphorous into the hole to encourage roots. For flowers, fruits and vegetables at blooming time, choose a fertilizer with potassium.