How to Make Soil More Alkaline Naturally (And Fix Acidic Soil)

If you’re wondering how to make soil more alkaline, you’re in the right place. Whether you’re starting a garden from scratch or trying to fix soil that’s too acidic, adjusting the pH naturally is easier than you might think.

In this guide, I’ll show you the best ways to raise soil pH using simple, natural methods. You’ll also learn what causes soil to become too acidic, what to add to make soil more alkaline, how to test your soil’s pH, and how to fix overly alkaline soil.

What Does Alkaline Soil Mean?

Alkaline soil has a pH level above 7.0. While neutral soil is ideal for many plants, some plants will thrive in slightly more alkaline conditions. Knowing your soil’s pH is the first step in understanding what your garden needs. A simple soil test kit can help you find out for sure.

How to Test Your Soil’s pH Level

The best way to determine the pH of your soil is through soil testing. You can use an affordable home pH meter or a rapid test kit that also checks nitrogen, phosphorus, and potassium levels. For a no-cost option, try these pantry-friendly tests:

Vinegar Test (for Alkaline Soil)

Place 2 tablespoons of soil in a bowl and add 1/2 cup of vinegar. If the mixture fizzes, your soil is alkaline.

Baking Soda Test (for Acidic Soil)

Place 2 tablespoons of moist soil in a bowl, then add 1/2 cup of baking soda. Fizzing indicates acidic soil.

If neither test causes a reaction, your soil is likely neutral.

Why Make Soil More Alkaline?

Some vegetables, herbs, and perennials grow better in alkaline soils. If your plants are struggling despite proper watering and sunlight, acidic soil could be the problem. Making the soil in your garden more alkaline can:

• Improve nutrient absorption
• Balance overly acidic soil
• Create a better environment for alkaline-loving plants like lavender, lilacs, clematis, and hydrangeas (if you prefer pink blooms)

How to Make Soil More Alkaline Naturally

Raising the pH of your soil can be done safely and naturally with common household and garden materials. Here are the most effective ways to make your soil more alkaline:

1. Add Garden Lime (Calcium Carbonate)

Lime is one of the most common soil amendments used to raise pH. It comes in pellet or powder form and is easy to apply. Use dolomitic lime if your soil is also low in magnesium.

2. Use Wood Ash

Wood ash is a fast-acting soil amendment that raises pH levels. Sprinkle it sparingly over your garden beds and mix it into the top layer of soil. Use untreated ash only.

3. Crushed Eggshells

Eggshells are rich in calcium and decompose slowly to raise soil alkalinity over time. Crush them finely for faster results.

4. Baking Soda Solution

For small areas or potted plants, dissolve a tablespoon of baking soda in a gallon of water and apply to the soil. This method is temporary but useful in a pinch.

5. Crushed Seashells or Oyster Shells

Like eggshells, these are high in calcium carbonate and work slowly to raise pH while adding minerals to the soil.

6. Compost

Well-balanced compost has a neutral to slightly alkaline pH and improves overall soil structure. It’s slower-acting but great for long-term soil health.

7. Kiln Dust (Use With Caution)

Industrial byproduct kiln dust is rich in lime and can significantly raise pH. Consult local extension services for advice and follow safety guidelines when using.

8. Ground Limestone (Agricultural Lime)

Ground limestone, also known as agricultural lime, is a finely milled version of natural limestone that provides a long-lasting pH increase. It works more gradually than kiln dust but is safer and widely recommended for garden use. Apply evenly over your soil and work it into the top few inches for best results.

Compost: Enhances structure and slow pH balancing

Dolomitic lime: Raises pH and adds magnesium

Crushed limestone: Increases calcium and pH

Wood ash: Adds potassium and alkalinity

Crushed oyster shells: Great for long-term alkalinity

What to Add to Soil to Make It More Alkaline

• Dolomitic lime: Raises pH and adds magnesium
• Crushed limestone: Increases calcium and pH
• Wood ash: Adds potassium and alkalinity
• Crushed oyster shells: Great for long-term alkalinity
• Compost: Enhances structure and slow pH balancing

How to Treat Alkaline Soil (If You Go Too Far)

If you raise the pH too much, your soil can become too alkaline. Here’s how to fix it:

• Add peat moss to slowly lower pH
• Use elemental sulfur to neutralize excess alkalinity
• Water with diluted vinegar or coffee grounds

Want to Learn How to Make Soil More Acidic?

Sometimes the solution isn’t raising pH but lowering it. If your soil is too alkaline and you need to acidify it instead, check out my complete guide here: How to Make Soil More Acidic

Best Fertilizers for Alkaline Soil

Choose fertilizers labeled for high pH soils or containing:

• Calcium
• Magnesium
• Potassium

Examples include bone meal, wood ash, and lime-based fertilizers.

Alkaline vs. Acidic Soil: What’s the Difference?

• Alkaline Soil: pH above 7.0; often found in dry climates
• Acidic Soil: pH below 6.5; more common in rainy regions

Plants That Prefer Alkaline Soil

Some plants grow better in these conditions, some examples are

• Lavender
• Lilacs
• Clematis
• Yarrow
• Pink hydrangeas (color depends on soil pH)
• Cabbage and broccoli

Matching soil pH to your plants’ needs ensures better growth and nutrient absorption.

Frequently Asked Questions

Now you can confidently adjust your garden’s pH naturally and effectively. Be sure to test your soil regularly and make adjustments slowly to avoid harming your plants.

And if you’re dealing with the opposite issue, don’t forget to read: How to Make Soil More Acidic.

Happy gardening!

More Helpful Gardening Tips

• Raised Bed Soil Mix Recipe & Raised Bed Soil Calculator
• How to Dry Out Overwatered Soil Quickly
• 17 Cheap Ways to Add Nitrogen to Soil

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