How to Harvest Walnuts?

Harvesting walnuts involves waiting for the right time when the nuts are ripe, carefully collecting them, and then properly preparing them for storage. The key steps include knowing when to harvest, getting the nuts off the tree, removing their outer green husks, washing, and drying them.

When Walnuts Are Ready for Harvest

Timing is crucial for a successful walnut harvest. Walnuts are typically ready for collection in late summer to early autumn, usually from late August through September or October, depending on the variety and climate.

Look for these signs of ripeness:

• The outer green hull begins to split open, revealing the hard inner shell of the walnut.
• Some walnuts may naturally fall to the ground.
• The green hull might start to turn yellow or brown.
• When shaken, the nuts inside the hull feel loose.

It's important to harvest once these signs appear to prevent spoilage from pests, mold, or extended exposure to moisture.

Methods for Collecting Walnuts

Once walnuts are ripe, there are a few primary ways to gather them:

1. Shaking the Tree: This is a common and efficient method. You can shake walnuts loose from your tree to harvest them once they are ripe.

   • Manual Shaking: For smaller trees, simply use your hands to shake branches.
   • Using a Pole: For larger trees, a long pole can be used to dislodge walnuts from higher branches.
   • Tarps or Sheets: Lay tarps, old sheets, or plastic sheeting on the ground around the tree beforehand to make collection easier and keep the walnuts clean.
   • Immediate Collection: Collect the walnuts from the ground immediately after they fall or are shaken loose to prevent them from becoming stained, moldy, or attracting pests.

2. Waiting for Natural Drop: Walnuts will eventually fall from the tree on their own once fully mature. While this requires less effort, it can result in more stained or damaged nuts if left on the ground too long. Regular patrols of your orchard or yard will be necessary to collect them promptly.

Post-Harvest Processing: Essential Steps

After collecting the walnuts, they require several processing steps before they are ready for consumption or long-term storage.

1. Hull Removal (De-hulling)

The most immediate step after collection is to remove the outer green skin, also known as the hull or husk. This hull contains tannins that can stain your hands and the nut shells if left on too long, and it can also encourage mold.

• By Hand: You can remove the outer green skin with your hands. It's highly recommended to wear heavy-duty gloves (like gardening or dishwashing gloves) during this process to prevent severe staining of your skin.
• Stomping: For a large batch, you can stomp on a group of fruits to break them open. This can be done on a hard surface like a driveway or patio.
• Other Methods: Some people use a hard brush or even specialized hulling machines for very large harvests.

Do not discard the hulls where livestock might access them, as they can be toxic.

2. Washing the Walnuts

Once the hulls are removed, wash the walnuts thoroughly.

• Place the de-hulled walnuts in a large bucket or tub of water.
• Swirl them around and scrub off any remaining bits of hull, dirt, or debris.
• Remove any floating nuts, as these often indicate an empty or spoiled nut.
• Rinse them under clean running water until the water runs clear.

3. Drying the Walnuts

Proper drying is the most critical step for successful storage and preventing mold. Walnuts need to be dried slowly and thoroughly.

• Air Drying: This is the most common method.
  • Spread the washed walnuts in a single layer on screens, mesh trays, or old window screens.
  • Place them in a cool, dry, well-ventilated area out of direct sunlight. Good air circulation is essential, so avoid stacking them or placing them in sealed containers.
  • Good locations include a shed, garage, attic, or a dedicated drying rack.
  • Stir or turn the walnuts daily to ensure even drying and prevent mold.
  • Drying can take anywhere from 2 to 4 weeks, depending on humidity levels and air circulation.
• Dehydrator: A food dehydrator can be used, typically at a low temperature (around 95-105°F or 35-40°C) for several days until completely dry.

How to tell if they are dry: A fully dried walnut will produce a clean, crisp "crack" when broken open. The kernel inside should be brittle and snap, not rubbery or soft.

Storing Walnuts

Once completely dry, walnuts can be stored in their shells for an extended period.

• In-shell storage: Store dried, in-shell walnuts in a cool, dry place with good air circulation, such as mesh bags, baskets, or burlap sacks. Avoid airtight containers, which can trap moisture. They can last up to 6 months this way.
• Shelled kernels: For longer storage, crack the walnuts and store the kernels in an airtight container.
  • Refrigerator: Walnuts can be stored in the refrigerator for up to a year.
  • Freezer: For optimal freshness and longevity, freeze walnut kernels. They can last up to two years or more in the freezer.

Tools for a Successful Walnut Harvest

Having the right tools can make your harvesting process much smoother and more efficient:

• Heavy-Duty Gloves: Essential for protecting your hands from staining during de-hulling.
• Tarps or Ground Cloths: To collect fallen walnuts easily and keep them clean.
• Long Pole or Rake: For shaking walnuts from higher branches.
• Buckets or Bins: For collecting and transporting the walnuts.
• Nut Gatherer (Optional): Rolling nut gatherers can save your back if you have many walnuts to pick up from the ground.
• Brushes or Scrapers: To help remove stubborn hull pieces.
• Drying Screens or Racks: For proper air circulation during the drying process.

Harvesting Stages at a Glance

By following these steps, you can successfully harvest and preserve your homegrown walnuts, enjoying their rich flavor for months to come. For more detailed information on nut processing, resources like the University of California Cooperative Extension offer valuable insights.