Walnut > Year-Round IPM Program > Budbreak through Bloom > Nitrogen Fertilizer Timing

Walnut

Nitrogen Fertilizer Timing

Fertilizer recovery is greatest when application coincides with periods of high nitrogen demand from walnut trees. In California, apply one-half to two-thirds of the fertilizer nitrogen in spring, so it is available during the main flush of spring shoot growth.

Applying less than the full amount of nitrogen and making more than one application throughout the growing season increases uptake efficiency and minimizes leaching losses, especially in sandy soils where storage capacity is limited.

Multiple applications help maintain nitrogen in the root zone. Fertilizing from fall through winter is not recommended, because tree capacity for nitrogen uptake is low at these times.