Many people consider the soil’s pH level to be the most vital piece of information in your garden, and they’d be right! Without the right pH levels, plants can’t do much growing at all!
So, whether you’re a seasoned horticulturist or just starting out, you’ve come to the right place. Today, we’re going to tell you how to measure soil pH levels so you can make the most of your garden.
What’s Soil PH?
The pH level of the soil is a measure of how alkaline, acidic, or neutral it is. This measure can range from 14 down to 0 as follows:
- 0–5.0: strong acidity
- 5.0–6.5: moderate acidity
- 6.5–7.5: neutral
- 7.5–8.5: moderate alkalinity
- 8.5–14: strong alkalinity
What’s a Good Soil Balance?
We recommend that you test your soil pH each time you plant any new crop.
On average, soil usually has a pH level between 5 and 9. That’s a good thing because most vegetables and fruits prefer growing in slightly acidic soil.
So, the rule of thumb is to keep the soil’s pH levels at a healthy balance of about 6.5.
How to Measure the PH Level of Soil
Now that we know how critical soil pH can be, here are a few ways to test your soil.
Lab Testing
For precise, accurate numbers, you can always send a soil sample to get tested in a lab. Plus, some labs can be costly and take several days before they get back to you with the results.
That said, we should note that you should get a lab soil pH test every 2–3 years just to get an idea of how your soil and crops are faring. Lab analyses can also help if you’re having issues with the health of a certain plant or yield in a particular area.
Home Soil Test Kit
If you’re looking for something quicker, you can always do a pH test yourself using a home soil test kit. Remember to test the soil when it’s damp for the best results.
Also, ensure you measure the soil in the root zone at a depth of about 0–8 inches. If you can get it to go lower than eight inches, then all the better!
The downside is that these at-home kits usually don’t give you exact numbers. They will, however, provide you with an estimate of the pH levels of the soil in question.
This way, you get a ballpark estimate without spending precious time and money routinely mailing soil samples.
DIY Soil Test
Try this science experiment at home. It won’t give you accurate numbers, but it’s certainly a fun way to tell if the soil is leaning more toward being alkaline or acidic.
Check it out:
- First, get vinegar, baking soda, and two plastic or glass bowls.
- If your plants are growing in rows, take about 5–6 soil samples from various areas throughout the garden bed.
- Then, mix the samples and divide them evenly into the two bowls.
- Add half a cup of distilled water to each bowl.
- Next, stir the soil and water until it turns muddy.
- In the first bowl, add half a cup of vinegar. If the mixture begins to bubble or fix, then the soil pH levels are higher than 7.0, aka it’s alkaline. The more the fizzing, the higher the alkaline levels.
- If the vinegar doesn’t produce any chemical reaction, it’s time to move on to the second bowl to test for acidity using the baking soda.
- In the second bowl, add half a cup of baking soda and observe what happens. If there’s visible bubbling or fizzing, the soil is acidic or has a pH level lower than 7.0. Again, the more bubbles or fizzing, the higher the acidity.
- If there’s no reaction in either bowl, then your soil pH is neutral.
Related reads: Why testing soil pH is important
What’s the Soil PH Needed for Gardening?
Soil composition is influenced by several factors. Yet, it all starts with the pH.
To help you maintain a healthy, thriving garden, you need to know where you stand regarding soil pH. Having that information can help you plan which plants you can add to your garden.
Almost all growing plants thrive in soil that’s slightly acidic or ‘sour.’ That means the pH scale should be right around 6.5 pH.
Luckily, most of the soil found in North America falls into that range, which is why many areas are naturally abundant with a wide range of flora and fauna.
Yet, some like it more alkaline, or ‘sweet,’ like carnations, whereas grass prefers a neutral pH to grow and develop.
So, to help keep all your plants happy and vibrant, look at these pH levels for various vegetable and flowering plants.
What’s the Soil PH Needed for Vegetable Gardening?
We rounded up some common vegetables and categorized them according to their preferred soil type.
Acid-Loving Crops
Generally speaking, vegetables do best in slightly acidic soils between 5.8 and 6.5.
When pH values become lower or higher than this, it may result in nutrient deficiencies and a less than optimal growth rate.
Take a look at some vegetables that thrive in acidic soil:
- Potatoes (4.5–6.0)
- Apples (5.0–6.5)
- Peanuts (5.0–7.5)
- Eggplants (5.5–6.5)
- Turnips (5.5–7.0)
Alkaline-Loving Crops
There are a few examples that don’t conform to the rule above. One is asparagus, which prefers its soil to be slightly more alkaline.
Here are a few more examples:
- Cantaloupe (6.0–7.5)
- Cabbage (6.0–7.5)
- Beets (6.0–7.5)
- Watermelons (6.0–7.0)
- Peas (6.0–7.5)
What’s the Soil PH Needed for a Flower Garden?
Most ornamental plants prefer soil to be between 6.0–7.0. Yet, there’s such a wide variety of flowering plants that they’re bound to want different pH levels.
Here’s just a sampling to give you an idea of how varied the pH levels can be for a few common species:
- Camellias (4.5–6.0)
- Sunflower (6.0–7.5)
- Hibiscus (7.5–8.0)
- Chrysanthemums (7.0–8.0)
- Geraniums (6.0–8.0)
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What To Do If the Soil Is Too Acidic?
If the soil is too acidic, you need to make a few adjustments to make it more alkaline. It’s what experts refer to as ‘sweetening’ the soil because crops taste sweeter when grown in less acidic soil.
The most effective way to sweeten the soil quickly and effectively is to add some garden lime or dolomite lime made from pulverized limestone.
The main difference is that lime contains only calcium carbonate, whereas dolomite lime has varying amounts of magnesium, which does an even better job of raising pH levels.
Other options that also contain high levels of calcium carbonate and magnesium include:
- Clamshells
- Ground eggshells
- Bone or crab meal since it contains about 25% lime
- Dry wood ash from a fireplace or wood stove
What To Do If the Soil Is Too Alkaline?
Sometimes you just want to grow acid-loving plants, like blueberries, parsley, and azaleas. Yet, what do you do when your soil is naturally too alkaline? You lower its pH levels!
The main drawback of lowering the soil’s pH is that anything you use to make the soil more acidic will last less than one growing season. So, you’ll need to reapply every couple of weeks.
Here are some of the most common ingredients that can help make the soil more acidic:
- Garden sulfur
- Diluted vinegar at a ratio of 2 tablespoons to 1 gallon of water
- Peat moss, but it’s not a sustainable option
- Coco noir is good for soil conditions in general, and it’s more sustainable, but it doesn’t do as good a job of lowering pH levels
- Organic matter from evergreen trees
FAQs
Check out some common questions that can help shed light on soil pH levels and how they can benefit your plants.
Why is Soil PH Important?
As mentioned above, soil pH can make or break the development of your plants. That’s how much power it holds.
For example, pH levels directly affect a garden’s yields as well as how much nutrients are in the soil. Not only that, but it also determines how much of those nutrients your plant absorbs.
So, it doesn’t matter how much nitrogen and other nutrients you add to the soil. If it doesn’t have a good pH level, your plants won’t be able to benefit from any of it.
Which Testing Method is the Most Precise?
According to experts, the most accurate home testing tools are pH meters. They work by measuring the levels of hydrogen ions in the soil and then give a reading of the potential for hydrogen, hence the name ‘pH.’
Besides being accurate, these meters are portable, easy to use, and cost-effective.
What Are the Signs of Acidic Soil?
There are a handful of signs that can tell you whether the soil is acidic or not. So, before you get out your soil testing kit, take a look at these:
- A seemingly never-ending infestation of weeds like dandelions, sorrel, or knotweed
- A high volume of moss, pine, or oak trees
- Stunted grass growth with wilting blades or yellow spots in the lawn
- Clay or sandy soil
Conclusion
Now that you know how to measure soil pH, nothing can stop your plans from blooming year-round. Having that key piece of information that ties everything together means you can create a master plan for your garden to include many of your favorite plants without worrying about their health and well-being.