Can I Compost Potato Plants?

Potato plants are a common crop grown by home gardeners and farmers. As the potato growing season comes to an end, the question arises – can I compost potato plants? The stems, leaves, and haulms (foliage) contain valuable nutrients that could enrich a compost pile. However, there are also some potential risks to be aware of. In this article, we’ll explore the pros and cons of composting potato plants and best practices for doing it safely.

The Benefits of Composting Potato Plants

Composting potato haulms, vines, and leaves can provide the following benefits:

• Adds nitrogen – The greens of potato plants are high in nitrogen, an essential nutrient for compost. Nitrogen provides food for the microorganisms that break down organic matter

• Moisture content – Potato foliage contains a lot of moisture, helping to achieve the ideal 40-60% moisture level in a compost pile

• Nutrients – In addition to nitrogen, potato plants contain potassium, phosphorus, magnesium and micronutrients. These will enrich the finished compost.

• Material volume – Potato vines and leaves add bulk to the compost, improving air circulation and access for decomposing organisms.

• Reduces waste – Composting this green waste keeps it out of landfills and gives the nutrients a second life.

The Risks of Composting Diseased Potato Plants

While composting potato plants has benefits, there are also some potential risks:

• Spreading disease – Potato plants are susceptible to diseases like early and late blight. Composting diseased plants could spread blight spores to the finished compost. Using this compost in the garden could then transmit blight to other susceptible plants like tomatoes, eggplants and peppers.

• Toxic compounds – Potato foliage and skins contain glycoalkaloids such as solanine. These natural toxins protect the plant but in excess can be harmful to humans. Composting diseased or damaged potato haulms releases higher levels of glycoalkaloids.

• Volunteer potatoes – Small potatoes left on plant roots or stems may sprout and grow if added to compost. These volunteer potatoes can harbor disease.

• Slow decomposition – Whole diseased potato haulms decompose slower than chopped greens. The fungi and bacteria need access to plant cell walls to break the material down.

Best Practices for Composting Potato Plants

To gain the benefits of composting potato plants while avoiding potential issues, follow these guidelines:

• Inspect plants first – Check potato foliage and stems for signs of disease like blight or insect damage. Discard any diseased material.

• Chop/shred – Cut or shred potato vines, leaves and stems into smaller pieces before adding to compost. This speeds decomposition.

• Bury pieces – Bury chopped potato haulms under 10-12 inches of other compost materials like leaves or straw. This prevents regrowth.

• Maintain heat – Turn the compost pile regularly to distribute airflow and moisture. Monitor temperature using a compost thermometer, maintaining 130-150 Fahrenheit for several weeks to kill pathogens.

• Avoid tubers – Remove any small tubers clinging to potato roots or stems. Even small potatoes can sprout in compost conditions.

• Let cure – Allow finished compost to cure 4-6 weeks before use. This allows for further decomposition of any remaining potato particles.

• Use wisely – Avoid using compost with potato residue in the same veggie beds where susceptible crops will be planted. Or wait at least 2 years between potato crops and other nightshades.

Composting healthy potato plants provides an opportunity to recycle nutrients back to the soil. With proper precautions, the benefits can outweigh the risks in most home composting situations. Inspect potato foliage for disease, chop plant remains, bury in active compost, and maintain high temperatures. Monitor your compost closely when adding potato residue. With awareness and care, the whole potato plant can nourish next season’s garden.