Soil pH Meter/Testers


One of the easiest, cheapest,  and fastest way to test your soil’s pH is to use a soil tester, also known as a soil meter, which is  available at most garden centres or hardware stores.

The meter’s pH scale will give you a reading which show you the relative acidity or alkalinity of your soil. In essence, it is identifying how much hydrogen ions is concentrated in your soil for it in turn affects the availability of nitrogen (which is prominent in alkaline soil) or iron (prominent in acidic soil) to your plant.
Certain plants may want more of one or the other.

The scale on the meter ranges from 1 to 14 with 1 being extremely acidic (white vinegar ranks about a 3) and with 14 being extremely alkaline (household ammonia ranks about 11). Seven, the middle of the scale indicates neutrality.

Please click on the image to get a better view of the pH meter.

If the needle on your meter points to any number from 1 to 6.9, then the pH of your soil is acidic.

Seven is the midpoint of the scale and indicates neutrality.

If your scale indicates anywhere  from 7.1 to 14, then your soil is more alkaline.  The higher the number the more alkaline your soil is.

If your plant is not in soil which has the best pH value  for it, the plant will not thrive because it will not be able to access the nutrition from the soil and you will get a poor crop of vegetables.

By using a pH tester, you can idendify whether your soil is too acidic or too alkaline, and you can make the necessary adjustments so that  your plants will thrive.

Here are the most common pH ranges used by vegetables and plants:

Typical acid loving plants have an optimum range of pH 4.5 to 5.

Plants that flourish in a neutral soil enjoy a pH range of 7.3 to 7.4

Plants that flourish in soil that has a pH of 7.5 or higher are aquatic or semi-aquatic plants.

Any soil which has a pH  below 4.5  is too acidic

or if it  has a pH above 8 it is generally too  alkaline (high numbers)

so both extremes are very bad for your plants or vegetables.

Luckily most vegetables require a soil pH between 6.0 – 7.5, so testing your soil and amending it should not be too much of a problem.

Although pH itself does not indicate how much nutrient content you have in your soil, the level of the pH affects how easily your plants can access these nutients.

You can get ahead of the game by choosing plants that like your soil’s existing pH ; however, even though amending soil to change it is an uphill battle, it can be done.

The only drawback is that you may need to amend each year unless you’re using compost or organic material. Organic material will moderate pH for longer than the synthetic alternatives.

High pH: Soils with a high pH are alkaline. To lower the pH, mix some powdered garden sulfur into the soil surrounding the existing plants or into new planting beds.  Please be careful! Read the label carefully, and follow the directions to a “T”.

Low pH: Soils with a low pH are too acidic. To correct, add ground dolomitic limestone (garden lime) to the soil and mix in well to raise the pH level.  Again read the label carefully and follow the directions.  You don’t need that much to change the pH.

While constantly correcting soil ph for a whole garden can be tedious, you might want to create a separated bed for plants that prefer soil pH other that what’s  common in the garden.

For example, you may want to plant rhododendrons or azaleas who prefer an acidic soil pH of about 4.5.   To do that, you may plant them in a separate bed; that is, you might create a “more acidic bed” for these plants.Then you can work more often on this area to to keep it acidic, that is, in the range of 4.5 to 5.5.

To do so you could dump coffee grounds directly in this bed’s soil rather than in the composter, grind and add citrus fruit rinds to the soil, work in fallen pine needles along with the suggested remedy above.  There are also synthetic formulas you can buy, but the more natural your additives the longer your change will last.  Test often with your pH meter.

I’ve used one of these soil pH meters (testers) for years to test the soil in all my flower and vegetable gardens. It’s fast and extremely easy to use.

Click on photo for a better view.

To use one of these pH meters, simply do the following:

1. Be sure your soil is moist. If not, dampen slightly.

2. Push the probe about 8 to 10 cm into the soil, and twist the probe back and forth to make sure soil is distributed evenly across its surface. Wait 1 to 2 minutes for probe to become acclimatised.

3. Remove the probe and note the reading. Do not re-insert the probe in the sme hole. Wait aproximtely 3o seconds to take the second reading.

4. Repeat steps to ensure an accurate reading has been taken (Click each picture for a better view)

On a different post, I have listed the best soil pH range  for different vegetables and herbs.   If interested,  please navigate to