Can I put walnut in my compost bin?

NO ✋🏼

You can't put walnut into your composting bin!

Why We Avoid Composting Walnuts: Understanding the Risks of Juglone

The Dangers of Juglone in Walnut Trees

While composting is an excellent way to reduce waste and create nutrient-rich soil for our gardens, we must be cautious about the materials we include in our compost piles. One such material that we avoid composting is walnuts, including their shells, leaves, and other parts of the tree. The reason behind this is the presence of juglone, a natural chemical compound found in black walnut trees and other members of the walnut family, such as English walnuts, Persian walnuts, butternuts, and heartnuts.

Juglone is an allelopathic compound, meaning it can inhibit the growth and development of other plants. When walnut leaves, shells, or other debris decompose, they release juglone into the soil, which can accumulate and cause harm to sensitive plants. The toxicity of juglone can lead to stunted growth, wilting, and even death in some plants, making it crucial for us to be aware of its potential risks when composting. To learn more about the importance of maintaining the right balance of materials in your compost pile, check out this informative ebook on mastering the green-brown mix.

Plants Sensitive to Juglone

While not all plants are affected by juglone, there are many common garden vegetables, flowers, and herbs that are highly sensitive to this compound. Some of the plants that we avoid planting near walnut trees or using walnut-based compost include:

Tomatoes
Potatoes
Peppers
Eggplants
Asparagus
Cabbage
Peonies
Petunias
Lilies
Chrysanthemums

To protect our gardens from the allelopathic effects of walnuts, we refrain from composting any part of the walnut tree, including the leaves, shells, husks, and sawdust. By doing so, we minimize the risk of juglone accumulating in our compost and potentially harming our plants when the compost is applied to the soil. Using a composting bin can help keep your compost contained and prevent the spread of juglone to nearby plants.

Alternative Uses for Walnut Shells and Leaves

While we don't recommend composting walnut shells and leaves, there are alternative uses for these materials that can still contribute to a more sustainable and eco-friendly lifestyle. For example, walnut shells can be used as a natural abrasive for cleaning purposes or as a drainage material in potted plants. Walnut leaves can be used as a natural mulch around juglone-tolerant plants, such as black raspberries, black cherries, and some oak species.

Proper Disposal of Walnut Debris

When it comes to disposing of walnut debris, we suggest collecting the leaves, shells, and other parts of the tree and disposing of them in a separate area away from our compost piles and gardens. This helps prevent the unintentional spread of juglone and protects our sensitive plants from its toxic effects. A sturdy pitchfork can be a useful tool for handling and moving walnut debris.

Frequently Asked Questions

1. Can I compost small amounts of walnut shells or leaves?

We recommend avoiding composting any amount of walnut shells, leaves, or other debris to minimize the risk of juglone accumulation in the compost and potential harm to sensitive plants.

2. How long does juglone persist in the soil?

Juglone can persist in the soil for several months to a year, depending on factors such as soil type, moisture, and temperature. To be safe, we suggest waiting at least a year before planting juglone-sensitive plants in areas where walnut debris has decomposed. The Penn State Extension provides a helpful list of plants that are tolerant of black walnut toxicity.

3. Are there any plants that can tolerate juglone?

Yes, some plants are tolerant of juglone and can grow near walnut trees or in soil containing juglone. These include black raspberries, black cherries, some oak species, and certain varieties of grasses and herbs.

In conclusion, while composting is an excellent way to reduce waste and improve soil health, we must be mindful of the materials we include in our compost piles. By understanding the risks associated with composting walnuts and taking steps to properly dispose of walnut debris, we can create a thriving, healthy garden while minimizing the potential for harm to our plants.