How and when to conduct a soil pH test
Quality soil is one of the most important aspects of successful gardening. We must get it just right to suit the different needs of our plants. While getting the correct substrate quality, consistency, and drainage, we must also ensure a proper soil pH.
Some plants are not fussy when it comes to the pH level of their growing medium, whilst others have rather specific requirements. There are specific times when you should test the pH level of your soil and there are several ways to do it.
What is a Soil Test?
A soil test evaluates how acidic or alkaline the soil of your plants is. Technically speaking, pH stands for potential Hydrogen, and a soil pH test assesses and measures how many hydrogen ions are present in the growing medium. Soil with a pH below 7 is acidic. Soil with a pH of 7 is neutral, and one above 7 is alkaline.
Not all plants like or grow well in the same soil pH levels, some have specific requirements. Although most plants are adaptable, Azaleas, for example, prefer an acidic growing medium whilst Lilac shrubs grow best in an alkaline one.
When Should a Soil Test Be Done?
The best time to test your soil pH is before you plant any new plants or when creating a new garden bed. It is also a good idea to test your soil pH before planting a new variety of plants, especially if it has specific pH requirements. But this is not the only time you should check your soil pH.
It is recommended that you test the pH level of your soil every couple of years to keep on top of its quality. It may need to be amended over time, and the only way to tell this is by periodic testing.
How to Test Your Soil pH
You can test the pH level of your plant’s soil in several ways. The first way is to purchase a soil pH testing kit. A different approach to testing your soil pH is with a DIY method using household ingredients and supplies. Lastly, if you wish to, you could send a sample of your substrate to a lab to be tested for a more accurate measurement.
What you will need:
- A Soil pH Testing Kit
- Distilled water
- Clean glassware or containers
- A hand shovel
- A Measuring cup
- Clean glassware or containers
- Distilled water
- A coffee filter
- Baking soda
- White vinegar
How to test your soil pH with a soil testing kit
Testing your substrate with a soil testing kit is the easiest and most accurate method of determining its pH level.
- Firstly, you will need to collect a sample. Use your hand shovel, and dig to a depth of about 6 inches below the surface.
- Collect about 3 teaspoons of soil in a clean container. Ensure the sample is clean by removing debris, such as stones, leaves, and sticks.
- Pour distilled water into the container with the collected sample until both mediums are at the same level.
- Stir the mixture vigorously to aggravate it, then allow it to rest for 30 minutes.
- Pour the watered sample through a coffee filter to drain it into a new container. The coffee filter should collect the solids of the testing sample and allow the water to drain through.
- Use the pH testing strip from the testing kit, and dip it into the drained water. Follow the instructions on the testing kit to know how long to leave the strip in the water.
- When ready, remove the strip and refer to the testing kit to determine the outcome of the soil tests.
Repeat this process multiple times with soil from different areas of your garden for the best results. Compile the results to determine your garden’s average soil pH level.
How to test your soil pH using household supplies
With this method, you do not need to purchase any additional kits to perform the test. While the results are less accurate or precise as using a testing kit, they will still give you a rough idea of what kind of soil you are working with.
- As with the previous testing method, you will need to collect a sample of your substrate. It is best to take a selection from various areas of your planned planting location so that you have a blended sample.
- Split your blended sample into two containers.
- In one container, you will test for alkalinity in your soil. To do this, add half a cup of distilled water to your sample, and mix it.
- In the same container, add half a cup of white vinegar. If the mixture begins to fizz or bubble visibly, your soil has an alkaline pH level. The more pronounced the fizzling or bubbling, the higher the pH is.
- To test for acidity, add half a cup of water to the second container, and mix it.
- Next, add half a cup of baking soda to the second container. If the mixture starts to fizz or bubble visibly, your soil is acidic. The more forceful the reaction, the higher the acidity level.
If your substrate does not react during either test, you are in luck! This means that your soil has a neutral pH, which is what most plants prefer to grow in.
How to Amend Your Soil
Once you have tested your soil, you may find that your pH is not quite suitable for your plants. In this case, you will need to amend your growing medium to suit your plant’s preferences. If your soil is too acidic, you can raise its pH level by amending it with limestone. On the other hand, if it’s too alkaline, you can lower its pH level by amending it with sulfur.
- After amending your soil, do another soil test to determine if you have adequately adjusted it to your plant's needs.
- Check your soil pH regularly, at least once a year, to ensure it stays at a desirable level.
- When amending your soil, do so slowly so as not to over-amend it and miss your desired mark.
While many plants are not too sensitive to pH levels, some require a fairly perfect level – according to their needs. It is important to be aware of this when growing plants to get the best results.