Information On How To Raise Acid Level In Soil

Information On How To Raise Acid Level In Soil

By: Heather Rhoades

For gardeners growing an acid loving plant like blue hydrangea or azalea, learning how to make soil acidic is important to its overall health. If you don’t already live in an area where the soil is acidic, making soil acidic will involve adding products that lower the soil pH. Soil pH measures the alkalinity or acidity levels, which range from 0 to 14 on the pH scale. The middle (7) is considered neutral while levels falling below 7 are acidic and those above that number are alkaline. Let’s take a look at how to raise acid level in soil.

What Types of Plants Grow in Acidic Soil?

While most plants grow best in soils between 6 and 7.5, others are favorable to more acidic conditions. Some of the most common and sought-after plants actually prefer acidic soil, even though many of them may be grown in a wide range of growing conditions.

The acid-loving plants that you can grow in acidic soil include:

  • azaleas and rhododendrons
  • hydrangea
  • gardenias
  • camellias
  • wood anemone
  • bleeding heart
  • various carnivorous plants
  • holly shrubs
  • crepe myrtle
  • calla lilies
  • pine trees

Even blueberries thrive in this type of soil pH.

How Do I Make My Soil More Acidic?

If your plants aren’t growing in your soil conditions because of too much alkalinity, then it may be necessary to learn more about how to raise acid level in soil pH. Before making soil acidic, you should first perform a soil test, which your local County Extension Office can assist you with, if needed.

One of the easiest ways to make soil more acidic is to add sphagnum peat. This works especially well in small garden areas. Simply add an inch or two (2.5-5 cm.) of peat to the topsoil in and around plants, or during planting.

For another quick fix, water plants several times with a solution of 2 tablespoons vinegar to a gallon of water. This is a great way to adjust pH in container plants.

Acidifying fertilizers can also be used to help raise acidity levels. Look for fertilizer containing ammonium nitrate, ammonium sulfate, or sulfur-coated urea. Both ammonium sulfate and sulfur-coated urea are good choices for making soil acidic, especially with azaleas. However, ammonium sulfate is strong and can easily burn plants if not used carefully. For this reason, you should always read and follow label instructions carefully.

In some instances, applying elemental sulfur (flowers of sulfur) is effective. However, sulfur is slow acting, taking several months. This is also most often used by large-scale growers rather than the home gardener. Granular sulfur is deemed safe and cost effective for smaller garden areas, with applications of no more than 2 pounds (.9 kg.) per 100 square feet (9. square meters).

Sometimes recommended as a method of lowering the pH enough to turn hydrangea blooms from pink to blue is iron sulfate. Iron sulfate acts more quickly (two to three weeks) but should not be used on a regular basis as heavy metals accumulate in the soil, becoming harmful to the plants.

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Read more about Soil, Fixes & Fertilizers

Improving Clay Soil

If your garden has heavy clay soil, you know what a challenge it can pose to plants, not to mention gardeners. Heavy clay drains slowly, meaning it stays saturated longer after rain or irrigation. Then, when the sun finally comes out and the soil dries, it forms a hard, cracked surface.

On the bright side, clay soils are usually richer in nutrients than sandy soils are. And clay's tendency to hold water tightly can be an advantage.

Here are some tips for making clay soil more manageable and easier to work.

  • Soil test kit or commercial test
  • Organic mulches: compost and aged manure, straw
  • Wheelbarrow or cart
  • Shovel
  • Rake
  • Cover crop (wheat, rye, clover, or oats)

Test soil pH, and adjust as necessary. Clay soils are rich in nutrients, but if the soil is too acidic or too alkaline, those nutrients won't be available to the plants. Use a home test kit or send a sample to a soil testing lab, then follow the recommendations for adjusting pH. For most garden plants, a pH of 6.3 to 6.8 is ideal. Find a lab near you by checking in your telephone directory, or by calling your local cooperative extension office.

Add organic matter. This helps improve drainage and lighten heavy soil. It also provides nutrients for beneficial soil microorganisms which will, in turn, also help improve the soil. Before planting in spring, add compost and aged manure. A 2- to 3-inch layer worked into the soil to shovel depth is a good amount. Throughout the growing season, mulch with organic materials like grass clippings, shredded leaves, or additional compost. Since soil microorganisms literally "eat" organic matter, make a habit of continually adding it to your soil.

Build raised beds. Because clay soils hold water, creating raised beds can help improve drainage by encouraging water to run off. Raised beds can be a simple mound of soil, or can be constructed out of wood, brick, or stone. To lessen compaction, size the beds so you can reach the middle without stepping in the bed.

Mulch beds over the winter. Driving rain can really pack down bare soil, so keep beds mulched with organic matter both during the growing season and over the winter. A layer of straw over the beds will protect the soil from compaction and reduce erosion it can also help minimize weed growth. In the spring, transfer the mulch to the garden paths.

Plant a cover crop. A cover crop is like a living mulch. Different cover crops are appropriate for different regions. In the north, winter wheat and winter rye are popular choices in warmer regions, crimson clover and oats are commonly used. For a winter cover crop, sow after the last crops have been harvested. The following spring, simply till the plants into the soil, adding yet more precious organic matter.

Improving soil takes time, so don't expect overnight results. On the other hand, if you follow the above steps you should notice some improvement each year. Within a few years, you'll have rich, plant-friendly soil.

Add compost any time. However, if you are tilling in fresh or uncomposted organic matter, such as a cover crop, leaves, or straw, wait at least a few weeks before planting to allow the material to break down.

Why Is It Important to Test the Soil pH Level?

Whether you plant a novel blueberry patch or try to enhance the production of settled blueberry bushes, it’s quite important that you test the soil. In some places, the soil pH could be very high and examining the soil could tell how much high the soil pH is. The test of soil will enable gardeners to wonder how much effort their soil will require for growing blueberries well. A perfect soil pH for blueberries is from 4 to 5. If the soil pH goes higher than that, then you have to take some steps for lowering the pH for growing blueberries.

Four Home Remedies To Acidify Soil

Did you know that if your soil isn't acidic enough, your plants would not be able to grow well? There are some vegetables like turnips, potatoes and tomatoes which need an acidic soil to grow well. If you have a garden and you are all prepped up to make this beautiful place into a vegetable feast, then you should have a soil which is acidic in nature or you can make it acidic through some simple home remedies.

In a garden, having the apt soil will make sure that your plants are well looked after. Dry soil will not provide your vegetables with enough water content, therefore resulting in a dry crop. Therefore, a good soil, rich in acid, is necessary for your vegetable garden.

Take a look at some of the home remedies to acidify soil in your garden:


One of the home remedies to acidify soil in your garden is with the help of organic fertilisers. These organic fertilisers will raise the acidity of the soil in a few days. If you are concerned about what type of fertiliser to use in your garden, the liquid one is much more preferred for the summer months compared to the soil-like mixtures. When you go in for organic fertilisers, make sure that the label mentions acidic and the percentage too.

One of the best home remedies to acidify soil in your garden is with the help of vinegar. Although this is a natural way of increasing the acid in the soil, it is not a permanent fix. Vinegar is absorbed and depleted in the soil and in a few days, you will begin to see the improvement in your fruits and vegetables. All you need to do is add 2 tbsp. of vinegar to a gallon of water and water the soil with it. The soil needs to be watered for weeks and should be repeated after 3 months once you see the progress.

Peat moss is one of the home remedies to acidify soil in your garden. Peat moss is highly acidic in nature and is effective for small gardens. It is also good for soil drainage and if your plants are growing in clay-based soil, then peat moss is a bad option to use to increase the acidity. For light or loamy soils, peat moss is ideal.

Adding sulfur is a safe and inexpensive way to lower the pH of your soil, but it is also one of the slowest acting options when it comes to home remedies to acidify soil in your garden.

How To Naturally Increase Your Soil Acidity

Acid-loving plants like perennials, shrubs, ground covers, and trees can fill your garden with life and colors. But they thrive most successfully in acidic soils. Follow these steps:

1) Conduct A Soil Test

A pH is the standard measurement of the soil’s alkalinity and acidity. It ranges from 0 to 14, being 7 the neutral level. The soil below 7 is acidic, and above is alkaline.

Before attempting to either raise or lower the soil’s pH in your garden, conducting a soil test is essential. A soil test will help you determine whether the growing media you have is neutral, acidic, or alkaline. Determining soil pH is the first step for successful soil management.

To see whether the soil you have is alkaline or acidic, you can contact and send samples to a reliable soil testing lab for a pH test.

Another option is to conduct your own homemade soil acidity-alkalinity test using items commonly found around your home.

2) Consider How Wide Your Growing Areas Is

Determining your soil’s current pH level allows you to choose what method to use to increase the acidity in your soil.

Of course, there are some factors you have to consider. Apart from the soil pH, you also need to consider how wide the area is you’re going to amend and how fast you want results.

3) Know What Causes Soil Acidity

Wet climates and the following four factors are the significant contributors that make soil more acidic. These are: rainfall and leaching, decaying organic matter, acidic parent material, and the harvest of crops.

Excessive rainfall drains away elements like calcium, magnesium, sodium, and potassium. These are the elements that potentially prevent soil acidity. Also, the decaying organic matter produces hydrogen ions (H+), which are responsible for acidity.

The harvest of crops also contributes to increasing soil acidity. As the crops grow, calcium, magnesium, and potassium are absorbed by the plants for healthy growth. And as the yield increases, more nutrients are required, thereby removing them from the soil.

4) Manually Increase Your Soil’s Acidity Level

Natural soil acidification happens when the concentration of hydrogen ions in the soil increases. And ammonium-based fertilizers are significant contributors to soil acidification.

Soil is also acidified naturally when acid rain and other organic materials like lichens and algae break down rocks.

Plants take up nitrogen in the form of ammonium, the positively charged ions, and nitrate, the negatively charged ions. The rule is, plants tend to release a hydrogen ion (H+) when it absorbs an ammonium ion and releases a hydroxide ion (OH-) when a nitrate ion is taken.

However, plants cannot absorb nitrate during the assimilation process due to waterlogging and lack of oxygen. Unabsorbed nitrate is washed away by rainfall, causing an increase in the acidity of the soil. Here are some things you can do to increase the acidity of your soil.

Amend Soil With Compost

Photo by: Edward Howell on Unsplash

Adding an aged compost to your soil will help lower the pH level over time. The decaying organic matter in the compost is by far the best way to increase acidity in your soil.

Not only does it improve the soil structure and encourage more beneficial micro-organisms, but it also gradually lowers the pH in your garden.

Water Plants With Compost Tea

Photo by:

Watering your plants with homemade compost tea can also contribute to soil becoming more acidic. Compost tea is famous for feeding your plants fast-acting nutrients. Still, it can very much make the soil more acidic organically.

Apply Sulfur To Your Home Garden

Sulfur is another essential element growers use to bolster plant resistance against diseases. But it is also a natural substance that effectively acidifies soil in the garden.

Using sulfur is the most favored method of large scale growers, commercial gardeners, and farmers to acidify the soil. And you can definitely use it in your home garden too.

To determine how much sulfur you’ll need depends on the size of your garden, the starting pH, and how compacted or sandy your soil is.

Make sure to do your soil test to get accurate pH measurements before starting to amend your soil with sulfur. Follow the instructions carefully and let the natural wonder of elemental sulfur work on its own after the application.

Add Mulch

Using organic mulch among your garden beds is another way to acidify your soil naturally. As the materials break down gradually, the process helps acidify the soil.

Releasing beneficial nutrients and organic materials like bark, pine needles, and oak leaves into your soil can also boost soil acid naturally when used as mulch in your vegetable garden.

Consider Sphagnum Peat Moss

Peat moss is also famous for contributing to soil acidity. It is often used to amend the soil for acid-loving plants in sandy and slightly acidic soil. However, soil containing minerals like limestone is not acidified by adding peat moss.

Apply Coffee Grounds For Short-Term Solutions

There are lots of recommendations online how coffee grounds positively contribute acidity to the soil. However, coffee grounds do not acidify your soil permanently.

They’ll boost the soil acidity in the immediate area they’re added to, but definitely do not in the larger surrounding areas.

However, coffee grounds are rich in nitrogen. So, it can be an excellent addition to your compost pile if you are hesitant in using manure because of the concern about pathogens. It makes a perfect substitute for nitrogen-rich manure to amend your plants.

5) Maintaining Soil Acidity

Photo by Gabriel Jimenez on Unsplash

After all the hard work of making your soil more acidic, regular monitoring is necessary to maintain the soil’s pH level. Amend by adding compost and homemade liquid fertilizers when the pH starts to rise up again.

Also, make sure to conduct a soil test periodically. The use of elemental sulfur does not guarantee to keep the soil acidity. Changing climates and a decrease in precipitation in your area can cause soil pH to increase.

Final Thoughts

Understanding the concept of acidity and soil pH that affects your plant’s healthy growth helps you determine the elements your plants require to thrive and the elements that are toxic to them.

Soil acidity is measured and expressed as soil pH using a scale from 0-14, indicating values below 7.

Your plant requires other elements like zinc and iron to grow healthy. But they cannot absorb the nutrients when the soil is too alkaline or when the pH level is above 7.5.

Therefore, soil acidification by amending your garden to increase the amount of iron, zinc, and other micronutrients available is essential for your plant’s optimum growth.

Plants with yellowing of leaves are sometimes suffering from iron deficiency and not because of pest infestations.

And iron deficiency occurs when the soil has a higher pH than the plant can tolerate. The most common solution to this problem is to acidify the soil.

Understanding how to make your soil acidic naturally allows you to determine issues affecting your plant’s growth.

By keeping your soil healthy, your happy plants will surely thank you. If you have any questions, feel free to ask in the comment section below. Happy gardening!

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About Benita Abucejo

Hi there! My name is Benita Abucejo. What can I say? I truly love spending my days in the outdoors, specifically in the garden. Gardening has always been a strong passion of mine since I was a little girl. It has brought me so much joy and happiness that it is definitely safe to say that I will be a gardener for life. For a period of time, I was able to work with people who are into home gardening and I found it to be quite beneficial to my physical health, as well as my mental well-being. Here at Seasonal Preferences, I am going to share with you my experience and ideas so that you can fulfill yourself with the same satisfaction and happiness. Of course, if you have ideas, I would love to hear those as well! Being creative in the garden can really be quite fascinating so let's share our experiences and be the best gardeners we can be. With that being said, thank you for dropping by and please leave me a comment on one of my posts if you would like to get in touch!

Another long-term solution for acidic soil is to keep adding good quality compost to the area. While this won't have an immediate impact on the soil's pH, it will help improve it over time and provide any plants in the area with vital nutrients while you're getting the soil's acidity level under control. Add at least two to three inches of compost per year, either to the surface of the soil or dug into the soil, depending on what you're growing in that area. If you're growing perennials, shrubs, or trees simply topdress the area with compost. If it's a new planting area or one that you replant every year, such as a vegetable garden, then dig it into the top few inches of soil at or before planting time, or at the end of the season.

You can also use wood ashes to increase your soil's pH. If you take this route, just make sure that you haven't burned any treated woods or black walnut, which is generally toxic to other plants. Wood ash is best applied in the fall, at a rate of about five to 10 pounds per 100 square feet. If you decide to apply wood ash, be sure to dig it into the soil otherwise, the small, dusty particles will simply blow away.

Improving acidic garden soil isn't difficult, but it will take a bit of time and patience. Whether you choose lime, bonemeal, ash, or compost (or a combination of them) to help improve your soil, you'll have a healthier garden and stronger plants as a result.

DIY soil ingredients:

As mentioned, your DIY garden soil has three ingredients: topsoil, compost, and potting soil. Let’s take a closer look at each ingredient to see why each is important to your mix.


Topsoil is just what it sounds like – the top 5 to 10” of your lawn. You can purchase topsoil, or you can mix ingredients with your own topsoil.

Organic matter and microorganisms have the highest concentration in topsoil. These are essential for your garden.

The exact makeup of topsoil will depend on the area. For example, some topsoil may be more acidic than others.


Compost is organic material that has decomposed. It can be made up of vegetable and fruit scraps, houseplant trimmings, dead plants, sod from old garden beds, eggshells, holiday greenery, old herbs, coffee grounds, and tea bags or leaves (be careful if you have a problem with acidic soil), and old produce that is no longer good to eat.

You do not want to add things like dairy or meat to cause odor problems and attract pests. You also don’t want to add diseased plants to cause the disease to spread to your other plants.

If you don’t have the space to have a compost bin, you can also purchase compost. Just keep in mind that it won’t be as fresh as if you had made it yourself.

Potting soil

Potting soil is a confusing term as it actually doesn’t contain soil. Instead, it is made of peat moss, perlite, and/or vermiculate.

The purpose of potting soil is to add moisture balance. This is crucial if you’re growing your plants in containers or raised beds.

That’s it. You’re ready to start mixing your DIY garden soil so that you can fill your beds and start growing. Soon, your small plants will grow into vegetable and fruit-producing plants that will feed your family this summer.

If you’ve done things properly, you’ll end up with high yields that will allow you to freeze or can excess produce for the fall and winter.