Terminology Tuesday: What is Calcitic Limestone?

Table of contents

Short Answer

Calcitic limestone is used in gardening to modify soil chemistry, making it more conducive for plant growth by correcting soil acidity. The limestone primarily composed of calcium carbonate, which adjusts soil pH levels to a more neutral range without altering magnesium content. This is particularly valuable for gardens where magnesium levels are already adequate or for plants sensitive to magnesium. The application of calcitic limestone improves soil structure, enhances water penetration, root development, and increases the availability of essential nutrients like nitrogen, phosphorus, and potassium, leading to healthier soil and more vibrant plants. To use it effectively, you should test your soil’s pH, apply the limestone in fall or early spring, mix it into the topsoil, and water your garden afterward. While beneficial, it’s important to apply calcitic limestone based on soil test recommendations to avoid over-application, which can harm plant growth. The choice between calcitic and dolomitic limestone should depend on your garden’s specific calcium and magnesium needs, determined by a soil test.

What is Calcitic Limestone Used for?

Calcitic limestone plays a crucial role in gardening, acting as a key agent in modifying soil chemistry to favor plant growth. This natural mineral corrects acidity in soil, creating an environment where plants can thrive. Understanding its properties and applications helps gardeners enhance soil health and optimize conditions for their garden’s success. This article delves into what this limestone is, its importance in gardening, and how you can use it to benefit your garden.

What is Calcitic Limestone Used for

Understanding Calcitic Limestone

The limestone is primarily composed of calcium carbonate, a chemical compound that significantly influences soil chemistry. Unlike dolomitic limestone, which also contains magnesium, calcitic limestone offers a more focused approach to adjusting soil pH levels without altering magnesium content. This distinction makes this limestone especially valuable in gardens where the magnesium level is already adequate or where specific plant species are sensitive to magnesium levels. Understanding these differences helps you choose the right type of limestone for your garden’s needs, ensuring that soil conditions are optimized for plant health and growth.

Understanding Calcitic Limestone

Importance of Calcitic Limestone in Gardening

Calcitic limestone serves a vital role in gardening by adjusting soil pH to a more neutral level, which is essential for optimal plant growth. Most plants thrive in soil with a pH range of 6.0 to 7.0, and the limestone helps achieve this balance. (Lingenfelter, n.d.) It also improves soil structure, enhancing water penetration and root development. By increasing the availability of essential nutrients like nitrogen, phosphorus, and potassium, calcitic limestone directly impacts plant health and productivity. Understanding how to use this mineral effectively can transform your gardening efforts, leading to healthier soil and more vibrant plants.


How to Use Calcitic Limestone in Your Garden

To effectively use calcitic limestone in your garden, start by testing your soil’s pH. This step helps you determine the necessity and amount of limestone your garden needs. You can buy a soil pH test kit from a garden center or online.

Once you know your soil’s pH, follow these steps to apply the limestone correctly:

  1. Choose the right time: The best time to apply the limestone is in the fall or early spring. This allows the limestone to adjust the soil pH before planting season.
  2. Apply the limestone: Spread the calcitic limestone evenly over your garden soil using a spreader. The amount you’ll need depends on your soil test results and the size of your garden.
  3. Mix into the soil: For the limestone to be effective, mix it into the top 6 to 8 inches of soil. This can be done with a shovel or a tiller.
  4. Water your garden: After applying and mixing the limestone, water your garden. Moisture helps the limestone break down and begin adjusting the soil pH.

For best results, retest your soil’s pH annually and adjust your limestone application as needed. This ensures your garden soil remains at an optimal pH for plant growth. (Bob Battel, Michigan State University Extension, 2017)

Benefits of Calcitic Limestone for Garden Plants

Applying the limestone to your garden offers several benefits for plant growth and soil fertility. By adjusting soil pH to a more neutral level, it enhances nutrient availability, particularly nitrogen, phosphorus, and potassium. This improved nutrient uptake supports healthier and more robust plant growth. Additionally, calcitic limestone improves soil structure by increasing soil aggregation, which enhances water retention and drainage. This creates a more favorable environment for root development and reduces the risk of root diseases. The use of calcitic limestone in your garden can lead to more productive fruit and vegetable plants, more vibrant flowers, and overall healthier plant life.

Is Calcitic Lime Safe

Is Calcitic Lime Safe for Your Garden?

While calcitic limestone is beneficial for many gardens, it’s important to consider potential drawbacks and use it wisely. Over-application can lead to soil pH becoming too high, which can lock up nutrients and make them unavailable to plants, leading to nutrient deficiencies. It’s crucial to test your soil’s pH before application and follow recommended rates to avoid this issue.

Additionally, not all plants prefer neutral pH levels. Some, like blueberries and azaleas, thrive in more acidic soils. For these plants, using this imestone could harm their growth rather than benefit it.

To avoid overuse, apply calcitic limestone based on soil test recommendations and consider the specific pH preferences of the plants in your garden. This ensures that you enhance, rather than inadvertently harm, your garden’s productivity and plant health.

Calcitic Limestone vs Dolomitic Limestone

The main difference between calcitic limestone and dolomitic limestone lies in their chemical composition. Calcitic limestone is primarily composed of calcium carbonate (CaCO3), which effectively raises the soil’s pH and improves calcium availability. On the other hand, dolomitic limestone contains both calcium carbonate and magnesium carbonate (MgCO3), making it a source of both calcium and magnesium. (Jim Isleib, Michigan State University Extension, 2015)

This distinction is crucial for gardeners deciding which to use. The limestone is the preferred choice when soil tests show a deficiency in calcium but adequate levels of magnesium. In contrast, dolomitic limestone is beneficial in situations where the soil lacks both calcium and magnesium.

Another consideration is the speed at which they alter soil pH. Calcitic limestone may react slightly faster in the soil than dolomitic limestone due to the difference in magnesium content, which affects how quickly the limestone dissolves and thus how swiftly it adjusts the pH.

Choosing between calcitic and dolomitic limestone should be based on a soil test to determine your garden’s specific needs. This ensures that your application corrects soil imbalances effectively without inadvertently creating other nutrient issues.

Calcitic Limestone vs Dolomitic Limestone

Final Thoughts

Understanding and using the limestone appropriately in your garden can significantly enhance soil health and plant growth. By adjusting soil pH to optimal levels, improving soil structure, and increasing nutrient availability, this limestone creates a foundation for a thriving garden. However, it’s essential to apply it judiciously, considering the specific needs of your soil and plants. Testing soil pH and being mindful of the amount used ensures that your garden benefits fully from calcitic limestone without experiencing any negative effects. With careful application, gardeners can unlock the full potential of their soil, leading to a more productive and vibrant garden.


Bob Battel, Michigan State University Extension. (2017, September 8). Use of byproduct lime on agricultural soils. MSU Extension. https://www.canr.msu.edu/news/use_of_byproduct_lime_on_agricultural_soils

Jim Isleib, Michigan State University Extension. (2015, December 17). Should I use dolomitic or calcitic lime? MSU Extension. https://www.canr.msu.edu/news/should_i_use_dolomitic_or_calcitic_lime

Lingenfelter, D. (n.d.). Soil Acidity and Aglime. https://extension.psu.edu/soil-acidity-and-aglime

Disclaimer: Information in this article without an APA citation comes from our personal knowledge and collective experience. It reflects years of practice and informal discussions, not directly cited from scientific sources. For more information, read our editorial policy.


Steve Mille

Steve Mille

I'm Steve Mille. Before I retired, I spent my days among trees and plants as a forester. My passion didn't end there. For 40 years, I've volunteered at botanical gardens across the country. I've learned about different climates and the plants that flourish in them. I often visit high schools to teach and talk about gardening. Sharing this passion is something I love. I also contribute to BestoftheGardenState.com, where I get to reach even more people.


Stay tuned

Do you want to be informed about the latest articles filled with handy tips and essential tools for your garden? Then sign up for our newsletter. We promise not to overload your inbox – we dislike that just as much as you do.