Which plants do not like manure?

Certain plants can be harmed by manure, especially fresh, nitrogen-rich varieties. These include seedlings, acid-loving plants like blueberries and azaleas, and plants with shallow root systems that can easily be burned. It’s crucial to use composted manure and apply it correctly to avoid damaging your garden.

Understanding Manure and Plant Sensitivity

Manure is a fantastic natural fertilizer, packed with nutrients that can boost plant growth. However, not all plants welcome it with open arms. The key lies in the type of manure and its stage of decomposition. Fresh manure is often too potent, containing high levels of ammonia and salts that can "burn" plant roots.

Why Some Plants Dislike Manure

• High Nitrogen Content: Fresh manure, particularly from poultry and horses, can have very high nitrogen levels. This can lead to excessive leafy growth at the expense of flowers or fruits, and in severe cases, can damage or kill plants.
• Salt Buildup: Manure contains salts. When applied in large quantities or too frequently, these salts can accumulate in the soil, making it difficult for plants to absorb water and nutrients. This is known as salt toxicity.
• Ammonia Burn: Ammonia, a gas released during the decomposition of fresh manure, can be toxic to plants. It can scorch leaves and damage root tissues.
• Pathogens and Weed Seeds: While less common with well-composted manure, fresh manure can sometimes contain harmful pathogens or viable weed seeds that can infest your garden.

Plants That Are Particularly Sensitive to Manure

While many plants thrive with aged manure, some species require a more delicate approach. Understanding these sensitivities can prevent common gardening mishaps.

Seedlings and Young Plants

Seedlings are incredibly vulnerable. Their delicate root systems are easily damaged by the high concentration of nutrients and salts found in even moderately aged manure. It’s best to avoid direct application of manure around very young plants.

• Best Practice: Use a seed-starting mix that is low in nutrients. Once seedlings have established a stronger root system, you can gradually introduce diluted liquid fertilizers or a thin layer of compost.

Acid-Loving Plants

Plants that prefer acidic soil conditions can be negatively impacted by manure. Many types of manure tend to be alkaline or neutral, which can raise the soil pH. This makes it harder for these plants to absorb essential nutrients like iron, leading to yellowing leaves (chlorosis).

• Examples:

  • Blueberries
  • Azaleas
  • Rhododendrons
  • Hydrangeas (especially those you want to be blue)
  • Evergreens like pines and firs

• Alternative Fertilizers: For these plants, opt for fertilizers specifically formulated for acid-loving plants or use organic amendments like peat moss or pine bark mulch.

Plants with Shallow Root Systems

Some plants have shallow root systems that are more exposed to the potential "burning" effects of manure. These roots are closer to the soil surface where manure is often applied.

• Examples:

  • Many herbs (like basil and parsley)
  • Certain leafy greens (like lettuce and spinach)
  • Some annual flowers

• Application Tip: If you want to amend the soil for these plants, incorporate well-rotted compost deeply into the soil before planting, rather than top-dressing with manure.

Specific Plant Families to Watch

While not a strict rule, some plant families are generally more sensitive to the strong effects of manure.

• Orchids: These epiphytic plants are not adapted to rich soil and can be easily killed by direct fertilization.
• Carnivorous Plants: These plants have evolved to thrive in nutrient-poor environments and will be harmed by the high nutrient content of manure.

The Importance of Composting Manure

The key to safely using manure in your garden is composting. Composting breaks down the harsh compounds in fresh manure, reducing the risk of burning plants and killing off weed seeds and pathogens.

What is Composted Manure?

Composted manure is manure that has undergone a heating process (either naturally or through active composting) that breaks down its components. This process transforms it into a stable, nutrient-rich soil amendment.

How to Compost Manure

1. Gather Materials: Mix manure with "brown" materials like straw, dried leaves, or sawdust to balance the carbon-to-nitrogen ratio.
2. Build a Pile: Create a compost pile, ensuring adequate aeration.
3. Maintain Moisture: Keep the pile consistently moist, like a wrung-out sponge.
4. Turn Regularly: Turn the pile every few weeks to aerate and speed up decomposition. The pile should heat up significantly during this process.
5. Wait for Maturity: The compost is ready when it’s dark, crumbly, smells earthy, and the original materials are no longer recognizable. This can take several months to a year.

Best Practices for Using Manure Safely

Even with composted manure, moderation and proper application are crucial for a healthy garden.

• Age is Key: Always use well-composted or aged manure. If you’re unsure, err on the side of caution and let it age longer.
• Mix it In: Incorporate composted manure into the soil before planting, rather than just piling it on top. This helps distribute nutrients evenly and prevents root burn.
• Dilute if Necessary: If using manure that is not fully composted, or if you’re concerned about its strength, mix it with other organic matter like compost or topsoil.
• Observe Your Plants: Pay attention to how your plants respond. If you see signs of stress like wilting or leaf scorch, reduce the amount of manure you’re using.
• Consider Your Soil Test: A soil test can tell you your soil’s nutrient levels and pH, helping you determine if and how much manure is needed.

People Also Ask

### Can I put fresh chicken manure directly on plants?

No, you should never put