If you’ve ever been confused by talk of acid or alkaline soil, this little primer on soil pH is for you! It explains the basics, and also lets you know how to amend your soil if needed.
Soil Testing
Soil testing has become extremely cheap and easy to do. Running a soil test is the single most important step you can take to ensure the success of your garden, provided you know what to do with the test results.
When it comes to the importance of soil pH, a little analogy always helps: if your thermometer says you that you have a temperature of 101F, you don’t need to have studied immunology to know it’s time to take an aspirin. Likewise, if a pH test says that your soil’s pH is 5.2, you don’t need to have studied plant science to know that it’s time to add lime.
Soil pH: Acid and Alkaline
In terms of soil pH, any reading below 6 means your soil is acidic. The lower the number, the more acidic it is. Happily, this is an easy fix; adding lime will correct this problem.
On the other end of the spectrum, any reading above 7 means that your soil is alkaline (sweet). The higher the number, the more alkaline it is. Adding sulfur will correct this problem.
And that, right there, is most of what you need to know about pH. Read on to learn the rest.
Planting to Match Your Soil’s pH
Different plants have different pH preferences. Though most of them like a pH between 6 and 7, there are a number of acid-loving plants, and also a few alkaline-loving plants.
So, before you plant anything, do a quick test of your soil’s pH and write down the test results. Then put that away, and make a list of the plants you want to grow.
Next, take a look at the Old Farmer’s Almanac to find out the ideal pH range for those plants you want to grow. Does your soil pH fall within the ideal pH range of those plants?
If so, you’re in luck.
If not, you have two options:
- Substitute other plants that will do well in the pH of your soil.
- Modify the pH of your soil to accommodate your preferred plants. As we said earlier: Add lime if your soil is too acidic. Add sulfur if your soil is too alkaline.
Learning More
For additional information about how to make your soil less acidic, read Strengthen Your Soil with Agricultural Limestone.
Happy growing!
1 Comment
David Laderoute
February 25, 2014 at 9:40 pmAn excellent (and quick read) overview of the importance and general aspects of soil pH. Where I live in NW MO we deal with alkaline soil, so I often have to make it more acidic. Many people in this neck of the woods do not have a clue about pH and wonder why their Rhododendrons don’t grow well. 🙂 Aside from not enough acidity, they typically grow them in the wrong places – far too much sun.
Previously, I lived in New England where our challenge with pH was increasing the alkalinity.
In my experience, even areas in you own garden can lean one way or the other. For example, an open area particularly that has some fill under it may be alkaline. Move over to a forested area and it may be much more acidic.
The lesson to learn is to CHECK. Small test strips or even meters these days are quite inexpensive.