Fertilizing with Horn Shavings Before Applying Bark Mulch

While bark mulch is effective for suppressing weeds, it can have some negative effects on soil and plants. Understanding these challenges is key to using it successfully.

The Disadvantages of Bark Mulch

• Tannic Acid: Bark mulch releases tannic acid, which can adversely affect the soil’s pH and the health of certain plants.
• Nitrogen Depletion: The decomposition process of bark mulch requires nitrogen. It draws this essential nutrient from the soil, which can lead to a nitrogen deficiency for your plants, stunting their growth.

How to Counteract Nitrogen Depletion

To prevent nitrogen loss in the soil, you can amend it with a slow-release nitrogen fertilizer, such as horn shavings, before applying the mulch. This ensures that both the decomposition process and your plants have an adequate supply of nitrogen.

Application Guide

Follow this process for optimal results:

1. Prepare the Soil: In the spring, before applying any new mulch, spread a layer of horn shavings over the desired area.
2. Incorporate the Fertilizer: Gently work the horn shavings into the top layer of the soil with a rake or cultivator.
3. Apply Bark Mulch: Spread a layer of bark mulch approximately 5 cm (2 inches) thick over the prepared soil.
4. Annual Maintenance: For established beds, repeat this process each spring. Apply horn shavings on top of the old mulch layer, lightly work them in, and then add a fresh layer of bark mulch to maintain the desired thickness.