What Plants Don’T Like Horse Manure?

When it comes to using horse manure as fertilizer, it’s important to know that not all plants thrive with this organic material. While horse manure can be a nutrient-rich source for many plants, some are more sensitive to its high nitrogen content and can suffer from fertilizer burn or other adverse effects. In this article, we will explore the plants that may not appreciate horse manure and suggest alternative fertilizers that are better suited for their growth and development.

what plants don't like horse manure

Sensitive Plants

When using horse manure as fertilizer, it is important to consider that not all plant species respond well to its application. Some plants are known to be sensitive to horse manure due to its nutrient composition or potential contaminants. In this section, we will identify specific plant species that are known to be sensitive to horse manure and discuss their specific requirements.


Rhododendrons are beautiful flowering shrubs that add a splash of color to any garden. However, they are known to be sensitive to horse manure due to its high nitrogen content. Excessive nitrogen can lead to an imbalance in the soil, affecting the overall health of rhododendrons. If you plan to fertilize your rhododendrons with horse manure, it is essential to ensure proper composting or aging of the manure to allow for the breakdown of nitrogen compounds.


Similar to rhododendrons, azaleas are also sensitive to high levels of nitrogen. These flowering shrubs require a well-balanced nutrient composition in the soil to thrive. When using horse manure as fertilizer for azaleas, it is crucial to mix it with other organic materials such as compost or leaf mold to dilute the nitrogen content. This will prevent any potential harm to the plants and promote healthy growth.


Blueberries are acid-loving plants that require a specific pH level in the soil for optimal growth. Horse manure, being alkaline in nature, can disrupt the acidity balance necessary for blueberries. If you intend to use horse manure as a fertilizer for blueberries, it is recommended to test the pH level of the soil and adjust it accordingly by incorporating amendments such as sulfur or peat moss.


Lilies are delicate and elegant flowers that can add a touch of beauty to any garden. However, they are known to be sensitive to fresh horse manure. Horse manure contains certain compounds that can be harmful to lilies if not properly decomposed. It is advisable to compost or age the manure before applying it to lilies, ensuring that any potential contaminants have broken down and are no longer harmful.


Ferns are known for their lush foliage and ability to thrive in shaded areas. While they generally tolerate a wide range of soil conditions, excessive nitrogen from horse manure can negatively impact their growth. When using horse manure as fertilizer for ferns, it is essential to apply it in moderation and ensure that the soil is well-drained to prevent waterlogging, which can further affect their health.

It is important to note that while these plants are known to be sensitive to horse manure, the level of sensitivity may vary depending on factors such as soil composition, climate, and the specific type of horse manure used. It is always recommended to conduct thorough research and consult with gardening experts or local agricultural extension offices for specific guidelines on using horse manure as fertilizer for sensitive plants.

Acid-Loving Plants

Acid-loving plants are a unique group of plants that thrive in acidic soil conditions. These plants have adapted to grow in environments with a low pH level, typically below 7.0. The acidic soil provides specific nutrients and conditions that are essential for their growth and development.

There are several types of acid-loving plants, including azaleas, rhododendrons, blueberries, camellias, and ferns, among others. These plants have specific requirements when it comes to soil acidity, and maintaining the right pH level is crucial for their overall health and productivity.

One of the main reasons why acid-loving plants require acidic soil is related to nutrient availability. Acidic conditions help break down organic matter and minerals in the soil, making them more accessible to the plants’ roots. These plants have evolved to thrive in environments where essential nutrients, such as iron and manganese, are more readily available in acidic soils.

However, not all organic matter is suitable for acid-loving plants, and this includes horse manure. While horse manure is an excellent source of organic material for many plants, it may not be ideal for acid-loving varieties. The main reason is that horse manure tends to have a higher pH level, which can raise the overall pH of the soil and make it less suitable for acid-loving plants.

See also  Where To Buy Horse Steroids?

Additionally, horse manure may contain high levels of nitrogen, which can further alter the pH of the soil. Acid-loving plants typically prefer a more balanced nutrient profile, with moderate levels of nitrogen. Excessive nitrogen can lead to rapid growth but may also inhibit the uptake of other essential nutrients, impacting the overall health of the plants.

Another concern with using horse manure for acid-loving plants is the potential presence of weed seeds. Horse manure is known to contain weed seeds that can germinate and compete with the desired plants for resources. Acid-loving plants are often more susceptible to competition, as they require specific conditions to thrive. Therefore, using horse manure that may introduce weed seeds can be detrimental to the growth and development of these plants.

It is important to note that while horse manure may not be suitable for acid-loving plants, there are alternative organic materials that can provide the necessary nutrients without compromising the soil pH. Examples include pine needles, peat moss, and composted oak leaves, which have naturally acidic properties and are compatible with acid-loving plants.

In summary, acid-loving plants have specific soil requirements, including a low pH level. While horse manure is beneficial for many plants, it may not be suitable for acid-loving varieties due to its higher pH and potential presence of weed seeds. Using alternative organic materials with naturally acidic properties is a better choice for promoting the healthy growth and development of acid-loving plants.

Nutrient-Sensitive Plants

When it comes to gardening and plant care, it’s important to understand that not all plants have the same nutrient requirements. Some plants are more sensitive to specific nutrients and may not thrive if those requirements are not met. Horse manure, while a valuable organic fertilizer, may not always provide the necessary nutrients for these nutrient-sensitive plants.

Let’s take a closer look at some plants that have specific nutrient requirements and why horse manure may not be sufficient:

1. Acid-Loving Plants

Plants such as blueberries, camellias, and rhododendrons thrive in acidic soil conditions. These acid-loving plants require a lower pH level in the soil to absorb essential nutrients. While horse manure is rich in organic matter, it tends to have a more neutral pH level. For acid-loving plants, it may be necessary to amend the soil with additional acidic materials like pine needles, elemental sulfur, or compost made from acidic organic materials.

2. Nitrogen-Hungry Plants

Plants that have a high demand for nitrogen, such as leafy greens and some vegetables, require ample amounts of this nutrient for vigorous growth and development. Horse manure contains nitrogen, but its nitrogen content may not always be sufficient for these nitrogen-hungry plants. Supplementing with additional nitrogen-rich fertilizers like blood meal, fish emulsion, or composted chicken manure may be necessary to meet the plants’ nutrient requirements.

3. Calcium-Dependent Plants

Calcium is an essential nutrient for plants as it plays a vital role in cell development and structure. Some plants, like tomatoes and peppers, are particularly dependent on calcium for healthy fruit development. While horse manure does contain calcium, its availability to plants can be limited due to high levels of phosphorus and potassium in the manure. Using supplemental calcium sources like gypsum or crushed eggshells can ensure that calcium-dependent plants receive adequate amounts of this nutrient.

4. Microelement-Sensitive Plants

Microelements, also known as trace elements, are essential nutrients that plants require in small quantities for their proper growth and development. Plants like orchids, ferns, and carnivorous plants are often more sensitive to deficiencies or imbalances of microelements. Horse manure may not always provide a balanced supply of these microelements, making it necessary to incorporate specialized fertilizers or soil amendments containing micronutrients.

While horse manure is a valuable fertilizer for many plants, it’s essential to recognize that nutrient-sensitive plants may have specific requirements that may not be fully met by it. The key to successful gardening is understanding the needs of different plants and finding the right balance of nutrients to support their growth. By supplementing with additional fertilizers or soil amendments tailored to these nutrient-sensitive plants, gardeners can ensure optimal plant health and productivity.

Excess Nitrogen Plants

Excessive nitrogen levels in the soil can have detrimental effects on certain plant species. It is essential for gardeners and farmers to identify plants that are sensitive to high levels of nitrogen and consider alternative fertilizers to ensure their healthy growth. In this section, we will discuss the plants that are particularly sensitive to excess nitrogen and provide suggestions for alternative fertilizers.

See also  Can Horses Have Twins?

1. Lettuce: Lettuce is a popular leafy green vegetable that is highly sensitive to excessive nitrogen. When exposed to elevated nitrogen levels, lettuce plants tend to prioritize root and leaf growth over forming compact heads. This results in loose and bitter-tasting leaves. To avoid this issue, it is recommended to use a balanced fertilizer with a lower nitrogen content. A fertilizer with an NPK ratio of 10-10-10 or 5-10-10 would be suitable for lettuce cultivation.

2. Tomatoes: While tomatoes generally require a moderate amount of nitrogen for optimal growth, excessive nitrogen can negatively impact fruit production. High nitrogen levels promote excessive vegetative growth at the expense of fruit development. To prevent this, it is advisable to use a fertilizer with a lower nitrogen content, such as a 5-10-10 formula. Additionally, incorporating organic matter, such as compost or well-rotted manure, into the soil can provide a more balanced and slow-release source of nutrients.

3. Corn: Corn is a heavy feeder that requires a significant amount of nitrogen to thrive. However, excessive nitrogen can lead to tall, spindly stalks that are more prone to lodging. To prevent this, it is recommended to use a slow-release nitrogen fertilizer or supplement with organic matter, such as compost or aged manure. This will provide a steady supply of nutrients to support healthy growth without overstimulating vegetative development.

4. Strawberries: Excessive nitrogen can lead to lush foliage but reduced flower and fruit production in strawberry plants. To maintain a balance, it is advisable to use a well-balanced fertilizer with a lower nitrogen content, such as a 5-10-10 formula, during the growing season. Mulching with organic matter can also help suppress excessive nitrogen availability and promote better fruiting.

5. Beans: Beans are nitrogen-fixing plants that can obtain a significant portion of their nitrogen requirements from the atmosphere. Therefore, excessive nitrogen fertilization can lead to vigorous vegetative growth with fewer flowers and pods. To avoid this, it is recommended to use a well-balanced fertilizer with a lower nitrogen content, such as a 5-10-10 formula. Additionally, intercropping with nitrogen-demanding crops, like corn or squash, can help utilize excess nitrogen and maintain a healthier nutrient balance.

When considering alternative fertilizers for these nitrogen-sensitive plants, it is important to focus on nutrient ratios and slow-release options. Organic fertilizers, such as compost, aged manure, or fish emulsion, can provide a balanced nutrient supply while reducing the risk of nitrogen burn. Additionally, incorporating cover crops or green manure can help improve soil fertility and reduce the reliance on synthetic fertilizers.

In summary, excessive nitrogen levels can have detrimental effects on certain plants, including lettuce, tomatoes, corn, strawberries, and beans. To ensure their healthy growth, it is crucial to choose alternative fertilizers with lower nitrogen content and balanced nutrient ratios. Additionally, incorporating organic matter and practicing sustainable gardening techniques can help maintain a healthier nutrient balance in the soil.

Soil pH Effects

Horse manure is a common organic fertilizer used by gardeners and farmers to enhance soil fertility. While it provides many benefits, it can also have an impact on soil pH, which in turn can affect the growth and health of plants. In this section, we will explore the effects of horse manure on soil pH and how certain plants may be adversely affected by changes in pH levels.

The Influence of Horse Manure on Soil pH

Horse manure is considered a moderately alkaline organic material, with a typical pH range of 7.4 to 8.4. When horse manure is applied to soil, it releases various compounds that can alter the soil’s acidity or alkalinity.

One of the key factors that influence soil pH is the decomposition process of organic matter. As horse manure decomposes, it releases organic acids into the soil, which can lower the pH levels. These acids include acetic acid, formic acid, and butyric acid. Additionally, the breakdown of proteins in horse manure produces ammonium ions, which can increase soil acidity.

However, horse manure also contains carbonates and bicarbonates, which act as alkaline compounds. These compounds can neutralize the acidity caused by organic acids and help maintain a more balanced pH level in the soil.

Adverse Effects on Plants

Changes in soil pH can have significant effects on plant health and nutrient availability. Different plants have specific pH preferences, and when the pH deviates from their ideal range, they may struggle to absorb essential nutrients from the soil.

See also  Can You Spay A Horse?

In acidic soil conditions, which can occur when horse manure contributes to lower pH levels, certain plants may experience nutrient deficiencies. Acidic soil can hinder the availability of macronutrients such as nitrogen, phosphorus, and potassium, as well as micronutrients like iron, manganese, and zinc. As a result, plants may exhibit stunted growth, yellowing leaves, and reduced vigor.

On the other hand, alkaline soil conditions caused by horse manure’s alkaline compounds can also pose challenges for plant growth. Alkaline soil can lead to nutrient imbalances, particularly with regard to micronutrients. Some plants, such as blueberries and rhododendrons, are particularly sensitive to alkaline soil and may struggle to thrive in such conditions.

Additionally, extreme changes in soil pH can disrupt the beneficial microbial activity in the soil. Many soil microorganisms play crucial roles in nutrient cycling and organic matter decomposition. When the pH shifts dramatically, it can negatively impact these microorganisms, affecting the overall soil health and fertility.

Managing Soil pH

Given the potential adverse effects of horse manure on soil pH, it is essential to manage and optimize pH levels to ensure optimal plant growth. Here are some strategies to consider:

  • Regularly test the soil pH using a soil testing kit to monitor any changes.
  • If the soil becomes too acidic, consider incorporating lime or other alkaline amendments to raise the pH.
  • If the soil becomes too alkaline, consider adding organic matter such as compost or peat moss to help acidify the soil.
  • Choose plant species that are well-suited to the current pH conditions of the soil. Conduct research or consult with local gardening experts for guidance.
  • Practice crop rotation and diversify plantings to mitigate any long-term effects of pH changes.


Horse manure can have both positive and negative effects on soil pH. While it contains alkaline compounds that can help neutralize acidity, it also releases organic acids that can lower pH levels. These pH changes can affect nutrient availability and plant health. Careful monitoring of soil pH and implementing appropriate management strategies can help mitigate the adverse effects and maintain a healthy growing environment for plants.


1. What plants don’t like horse manure?

Some plants are sensitive to fresh horse manure due to its high nitrogen content, which can burn the roots or cause excessive foliage growth. These plants include tomatoes, peppers, potatoes, and other members of the nightshade family. It is best to compost horse manure before using it as fertilizer for these plants.

2. Can I use horse manure on all types of plants?

No, not all plants tolerate horse manure well. Aside from the nightshade family mentioned earlier, other plants that may not appreciate horse manure include leafy greens like lettuce and spinach, as well as root crops like carrots and radishes. It’s important to research specific plant preferences and use composted manure or alternative fertilizers accordingly.

3. How can I safely use horse manure in my garden?

To safely use horse manure in your garden, it is recommended to compost it first. Composting allows the manure to break down and age, reducing the risk of harmful pathogens and excessive nitrogen. Mix the composted manure with other organic matter, such as straw or leaves, to create a balanced and nutrient-rich soil amendment that can be used for a wide range of plants.


In conclusion, it is important to be mindful of the plants that may not thrive when exposed to horse manure. While horse manure can be a beneficial organic fertilizer for many plants, there are some that may not tolerate the high levels of nitrogen and salts found in this type of manure.

Plants that are sensitive to these conditions include acid-loving plants like azaleas, rhododendrons, and blueberries, as well as plants that prefer dry or well-drained soil, such as cacti and succulents. It is crucial to assess the specific needs and preferences of each plant before incorporating horse manure into the soil to ensure optimal growth and avoid any potential negative effects.

Remember to always conduct proper research or consult with local gardening experts to determine the best fertilizer options for the plants in your garden or landscape.