A soil's pH is the soil's level of iron content. The pH of a soil is directly responsible for how many nutrients a plant's roots will be able to absorb from the soil. In acidic soils--soils with a pH of 7.0 or lower--a plant struggles to absorb calcium, phosphorous, potassium and magnesium, while in Alkaline soils--those with a pH reading of 7.0 or above--vegetation has a hard time absorbing copper, zinc, boron, manganese and iron. Testing soil with a pH meter will tell you exactly how high or low the pH really is.
Collect soil samples from several areas in the garden, paying special attention to areas where the soil is different from others.
Place the samples into the same plastic container and shake the samples together.
Remove 2 tbsp. of a soil sample from your container, mix it with an equal amount of distilled water, and whisk it together.
Let the mixture stand for 10 to 15 minutes.
Turn on your pH meter and remove the protective cap, exposing its testing sensor, or attach the probes of the pH meter.
Touch the sensor to the soil until a reading appears on the meter. Record the reading for later use.