How to Propagate Walnuts? A Detailed Guide to Common Propagation Methods

Walnuts are a common nut in daily life. Due to their extremely high nutritional value and unique taste and flavor, they have gained consumer recognition, and more and more farmers are growing walnut trees. Below, the editor will introduce how to propagate walnuts.

1. Seed propagation

Sow the collected seeds in spring, or sow in autumn, when the temperature is suitable. In spring, March and April are the best sowing periods. The seeds must undergo stratification to promote germination before sowing; direct sowing rarely germinates. The stratification site should be a warm, sunny place, and generally, one layer of sand and one layer of seeds, maintaining a temperature of 2°C to 5°C. Humidity at around 60%. After two months of stratification, they can be taken out and sown. Therefore, stratification must be done in advance. Alternatively, before sowing, soak the seeds in cold water, soak and press the seeds, changing the water once a day, and after a week, expose them to the sun until the shells crack, then they can be sown. Sow in holes, place the seeds horizontally, cover with about 6 cm of soil, then water and manage.

2. Grafting for seedling propagation

Generally, hickory is used as the rootstock; wild hickory has strong adaptability, strong resistance, and sturdy stems. Grafting other varieties can bring fruiting earlier. For the scion, select one-year-old healthy branches with moderate internode strength and no pests or diseases from robust mother plants of excellent varieties. If there are many scions, they can be stored in moist sand. The rootstock should have a thickness of about 1.5 cm, and grafting should be done at a position about 10 cm above the ground. After cutting, grafting must be done immediately; bleeding affects survival, and the scion can be placed in the mouth to prevent bleeding. The cleft grafting method is generally used. After fixing, check frequently, and remove the film after survival.

3. Cutting propagation

Generally, cutting is the fastest method to produce seedlings. Cut one-year-old to 3-year-old branches from the outer part of the mother plant, with a thickness of 1.5 cm, and take branches about 15 cm long. Some trimming is also needed, leaving about 10 cm for the final cutting. Keep three to four leaves on the upper part of the branch, then soak the lower end in a rooting powder alcohol solution, and afterward insert it into a moist seedbed, cover with pine needles to keep warm, set up a shade net, and control the temperature between 18°C and 25°C, not exceeding 30°C and not below 10°C. Later maintenance is also needed.

The common propagation methods for walnuts are sowing, grafting, and cuttings. They are not easy to carry out, so more methods should be used to help propagation. However, these three methods each have their own advantages, and everyone can decide according to the actual situation.