Best pH for plants [Detailed Guide]

pH is very important for our plants. As a measure of our soil’s acidity or alkalinity, a pH reading lets us know if we have to take action. Outside of acid-loving plants like Blueberries and Azaleas, most of our garden crops want a fairly neutral pH. In this article, let’s dive into the world of pH and discover just how important this soil parameter really is.

What is pH?

pH is a scientific measurement scale of the relative acidity or alkalinity of a substance or solution, in this case, our soil. It uses a 14-point scale with 7 being neutral which would be something like pure water.

Anything below 7 is considered acidic and anything above is considered alkaline.

The ph of the human body is around 7.4.

What pH do plants want?

Excluding acid lovers such as blueberries, most of our crops need a neutral ph. There are two ranges we’re concerned with though. The range in which our plants can survive which is between 5.5 and 7.5 and then there’s the optimal range, the range in which our plants thrive and that’s between six and seven.

So neutral to slightly acidic is what we’re after.

Why pH is important for plants?

When the pH of your soil falls outside of the optimal range nutrients and water get increasingly harder and harder to obtain by the plant’s roots.

Chemical processes in highly acidic and highly alkaline soils block this uptake and the plants suffer. Ok, so how do we measure it? Well, you can take a soil sample from your garden and send it off to a lab for analysis but that takes time and it’s not cheap. However, these inexpensive meters that you can buy online work just as well to give you a quick idea of how your soil is doing.

Fixing a pH problem

Fixing an extreme ph that falls outside of the range we want almost always involves adding something to the soil.

The safest two additions that I use are dolomite lime for acidic soils and elemental sulfur for alkaline ones.

Always check the packaging for application rates but err on the side of less. Drastic pH changes are often way worse than the ph problem itself.

Thanks for reading guys. Happy gardening!

FAQs on best pH for plants

Is 9.5 pH water good for plants?

For any plant, never use water with a pH of more than 8.5.

How do you correct pH in soil?

The use of limestone neutralizes excessively acidic soil (available at garden centers). Agricultural limestone in the form of powder or pellets is most frequently utilized. It is considerably simpler to raise pH than to lower it, so be careful not to use too much lime.

What happens to plants if the pH is too high?

Micronutrients (particularly iron) are less soluble and inaccessible to plant roots when the pH is too high. Within one to two weeks, a high-pH-induced iron deficit can manifest itself, resulting in chlorosis of new growth and general stunting.

What happens to plants if the pH is too low?

Plants will struggle to absorb nutrients through their roots when the pH of the soil is either too low (acidic) or too high (basic).

What is the fastest way to raise pH in soil?

Increasing the pH of the soil. Applying a substance that contains some kind of lime is a frequent approach to lessen the acidity of soils.

Does fertilizer change soil pH?

Soil pH is impacted by nitrogen levels. Fertilizers, manures, and legumes are all sources of nitrogen that either contains or produce ammonium. If the plant doesn’t directly take the ammonium ions, this causes the soil to become more acidic. The rate at which nitrogen is fertilized increases with soil acidity.

Does low pH cause yellow leaves?

Low pH conditions are indicated by your plants’ stunted development, yellow leaves, or leaves with brown patches or reddish-purple borders.

Which fertilizer is least likely to affect the soil pH?

The K fertilizers are least likely to change the pH of the soil compared to N and P fertilizers.

What water pH is best for plant growth?

The pH of the water should be between 5.5 and 7.0 for the majority of plants to thrive (slightly acidic to neutral). The pH will rise, making the water more alkaline.