Do you know your soil pH… do you care?
This is the fourth installment in a series on plant nutrients and fertilizers.
(Part 1 is here.
Part 2 is here.
Part 3 is here.)
Many folks think about “fertilizing” their soil… which of course is a good thing. However, soil pH is a strong determinant of whether or not the nutrients in the soil are available to the plants.
Soil pH can also encourage or discourage disease.
What is pH?
pH is scored on a scale of 0-14. 0-7 is acidic; 7-14 is basic or alkaline.
Plants differ on their preference, tho in general, slightly acidic is best: 6.0-6.5
<>Primary and <>secondary macronutrients tend to be better available in more alkaline soils (high pH). <>Micronutrients tend to be better available in more acidic soils (low pH).
Soil bacteria and fungi are also influenced by pH. The optimal range for good soil bacteria is 6.3-6.8 (slightly acidic). Bacteria tends to multiply in a highly acidic environment. This leads to “souring” and putrefaction.
Essentially, when you soil pH is in the optimal range you’ll get bacteria action which fuels good decaying which makes nutrients available to the plant which allows healthy plant growth.
Testing pH
There are a number of home test kits on the market. You can likely find them in a decent size garden center. Here’s one available from Amazon.
Your pH can vary so you’ll want to test different areas/beds.
In general, areas with a lot of annual rainfall are more acidic, low rainfall areas tend to be near neutral (7.0). That doesn’t account for any treatments that have been applied
Correcting pH
Low pH or acidic soil: The quickest way to raise pH is to add a garden lime. You can also use crushed egg shells. Both lime and egg shells are primarily calcium carbonate. Garden lime is relatively inexpensive and already finely powdered.
As with any soil treatment, follow the quantity guidelines. You don’t want to over shoot and make your soil too alkaline.
High pH or alkaline soil: Sulfur will lower the pH. Again, be careful not to over apply and create a too acidic environment.
Here are a few more like this one:
