6 Ways: How To Make Soil More Alkaline Naturally

Red flowering tulips are growing on slightly alkaline soil.

Most plants prefer a neutral soil around pH 6.5 to 7.5. However, all the plants in your garden have their own individual soil preferences and those include the ones that thrive best in more alkaline soil.

To help you gardeners out, we will be discussing some easy procedures you can implement to make your soil more alkaline among your garden.

The majority of shrubs, vegetables, fruits, and flowers prefer slightly acidic soil. But some perennials such as bulb plants, a couple of ornamental grasses, clematis, flowering vines, and many others are alkaline-loving plants.

Knowing the right soil pH in your garden is essential for the health of your plants. Soil pH determines how well your plants absorb nutrients to grow healthy.


6 Ways How To Raise Soil pH Naturally


1) Conduct a Soil Test

A soil test will help you determine if the soil in your garden contains the nutrients your plant needs. As some growing media are naturally deficient in nutrients, your plants will require some changes to your soil pH.

Some soils have sufficient levels of nutrients at the start. But over time, continuous removal of crop harvest will deplete the reserves.

Soil testing is done routinely, particularly in most advanced crop-production areas that practice crop rotation, to determine the primary nutrients your plant needs. You can do it too in your home garden to ensure higher yields.

Suppose you’re unsure whether the soil you have in the garden is alkaline or acidic, you can either contact and send samples to a reliable soil testing lab for a pH test or do a DIY soil acidity-alkalinity test using items commonly found around your home.


2) Amend Soil With Compost

Ground compost on a left hand.

Once you have the results, you can now compare them to your desired pH. And if it requires you to adjust the soil’s pH just a bit, adding several inches of organic compost to your garden will help you increase the pH to make the soil more alkaline.

Most finished compost is close to a neutral pH level, and adding it into your garden will raise the soil’s organic content.

An increase in organic matter allows the soil to recover natural buffer capacity. This activity also means to amend and increase pH in acid soils.


3) Add Lime To Increase The Soil pH

Four fragments of limestone.

  • Which Lime Should You Use?

You can use several liming materials to increase the pH of your soil if you have highly acidic soil. Knowing the effectiveness of lime varieties allows you to determine which one will do the best job in your garden and give you the best value for your money.

So before making a purchase, look for the following lime characteristics to ensure you get the best one for your gardening needs.

  1. The neutralizing value (NV) tells you the lime’s effectiveness in stabilizing the soil acidity.
  2. Fineness is your lime’s particle size, and this characteristic determines how fast lime amendments will react in the soil.
  3. The calcium and magnesium content in your crops helps you decide which type of lime to buy. The soil test results help you determine how much calcium and magnesium your crops need. You can find the percentage marked on the bag when purchasing lime to use.
  • Different Types of Liming Materials

1) Calcium carbonate, known as agricultural lime, is a natural rock plant growers commonly use to raise acidic soil pH on the North Coast.

2) Calcium oxide, known as burnt lime, is more concentrated than agricultural lime. This type is more unpleasant to handle and is rarely used in farming.

3) Crushed oyster shells are calcium carbonate. However, this is also rarely used in farming as the seashells are too coarse to be effective in the soil.

A cluster of oyster shells

4) Dolomite is a naturally occurring rock that is a mixture of calcium carbonate and magnesium carbonate.

With a neutralizing value of 95–98 and 22% calcium and 12% magnesium, dolomite is considered good quality lime and efficient for acidic soil.

However, frequent dolomite use can cause a nutrient imbalance due to its 2:1 ratio, as the soil should be around 5:1.

5) Magnesium carbonate, known as Magnesite from crushed magnesium carbonate rock, has 25–28% magnesium, no calcium, with a neutralizing value of 95–105.

6) Magnesium oxide, known as burnt magnesite is often sold in granulated form. The lime contains about 50% magnesium, and with a neutralizing value of 180–220, it is a perfect amendment to use if your acidic soil has sufficient calcium.

7) Wet lime is often sold at an affordable price. Its effectiveness is determined by how much water content it has and the NV. The lime with a water content of about 10% is only 90% effective.

8) Lime and cement kiln dust have almost similar properties and are useful in farming. The only difference is that the cement kiln has a significant amount of calcium. However, both are too fine and are difficult to handle. This requires you to ask an expert to spread the product evenly.

  • Adding Lime Improves Nutrient Availability To Your Plants

Early bloomer lavender crocus.

Adding lime to the soil will significantly increase the soil pH. Its primary function is to raise the soil pH organically and considerably reduces soil acidity.  Besides, the compound help improves the nutrients’ availability to the plants.

  • Reverse Soil Acidification

Soil acidification or a decrease in soil pH occurs naturally, accelerated by crop production practices. Adding lime to established perennials or top-dress lime to no-till crops is beneficial to reverse soil acidification.

However, some gardens present different soils, and the application of lime will vary for it to be advantageous to your garden. Please take note that liming with different soils vary in its effectiveness.

  • Incorporate Lime or Top-Dress Lime

You can apply lime in your garden in two forms. You can either incorporate lime into the soil or top-dress on the surface.

If you’re into a no-dig gardening practice and prefer to top-dress lime on the soil surface, know that the pH will only increase an inch or two from the soil’s top surface. Lime must contact acidic soil to react and raise the soil pH.

  • Recommended Adjustments

The amount of limestone you’ll need to adjust the soil’s pH depends on the soil type and natural pH level.

A clayey soil high in organic matter requires more considerable amounts of limestone to reduce acidity than a sandy soil lower in organic matter, given each soil has the same pH level to begin with.

If both silt loam soil and loamy sand have the same pH of about 5.5 and you want to raise the pH level up to 6.5 for both soil types, loamy sand will only require about 1 to 1-3/4 tons of limestone per acre to adjust the soil acidity.

However, a silt loam would require about 2-3/4 to 4 tons of limestone per acre to increase the soil pH to 6.5.

  • Lime Application

How often limestone is applied to your garden also depends on the soil type and how fast it drains.

Sandy soils require frequent application because these types of soil hold less calcium and magnesium than a garden higher in clay and organic matter.

If your soil does not drain fast, you don’t have to apply lime frequently, as the leaching of basic cations in poorly drained soil conditions will take time.


4) Use Wood Ash To Increase Soil pH

A piece of wood charcoal.

Wood ashes are also used to increase soil pH naturally, and they can increase the pH in your soil by up to 59%. This substance is abundant in calcium, potassium, magnesium, and phosphorus, with an average NPK ratio of about 0-1-3.

However, the frequent use of wood ash can raise the soil’s pH value to a very high level, causing plants nutrient deficiency, especially in sandy soils. So please use moderately.

Wood ash can also cause damage when in contact with germinating seedlings or plant roots. So, remember to use wood ash sparingly and carefully in your garden.


5) Water Soil Generously

Watering a farm using a garden hose.

Water your garden generously, ensuring the soil is well saturated of at least 6 inches depth. Watering encourages soil amendments to work actively. However, make sure not to overwater to avoid minerals and nutrients from draining out of the soil.


6) Conduct Soil Test Regularly

Checking the soil by hand.

After a few months of application, you may want to conduct a soil test again to see how your amendment are working. The retest will help you determine if you used the right amounts and if those amounts are working to raise your soil pH level.

Limestone usually takes longer to breakdown, so it might take a little while to see positive results. However, monitor the soil as frequently as possible to know if you need to apply another round of limestone.

pH levels in your garden are mostly affected by the lack of rainfall, fertilizers applied, and significant changes in your garden’s condition.

Regular soil tests will help you monitor the pH level to determine the appropriate remedy as needed, before an imbalanced pH level can cause damage to your plants.


Final Thoughts

Managing soil pH is essential because it influences the nutrients available to your plants. It also helps increase your crop income and improve your lawn and garden performance.

However, it requires knowledge to determine how the soil becomes acidic or alkaline and their respective significant functions to practice best soil management. The right soil pH may lead to greater yields – be it on a large scale farm or in your home garden.

We hope you enjoyed these productive and cost-effective tips how to increase your soil’s alkalinity for you to have a more efficient gardening experience.

Any tips you would like to add to the list? Feel free to share in the comment section below. Happy gardening!

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!

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