The decision to replant almonds after the existing orchard is retired may not be as simple as ordering new trees and booking the removal company. As one Central California farmer explains, the questions don't start and stop with selecting variety and rootstock.

Denair, Calif. farmer Cal Mast knew well ahead of time that he had some planning to do. The orchard his father-in-law planted on pasture ground adjacent to the family dairy revealed some issues needing addressed if the next 25 years is going to do better than the last.

Land preparation

Mast knew that he had a problem area where water would collect. He points to the corner of the parcel on a map where trees suffered and died because of drainage issues. Though he did not need to level the property because the planned drip irrigation system will overcome those issues, there was nevertheless some work to be done to address how water can drain from the sloped former pasture.

He also learned that reconfiguring the orchard 90 degrees to a north-south configuration would likely benefit production and tree growth. He also wanted slightly wider rows.

The north-south decision was based primarily on light. Rows configured east-west can see trees – particularly those at the south edge of the orchard – bend to the south as they chase the light, he said. He says he is familiar with an east-west orchard near him with a significant fungal disease problem, though he's unclear if that is attributable to the configuration.

Mast was told that configuring the rows north-south can help capture light better across the orchard without the south side of the orchard leaning towards the sun.

"They may lean a little bit within the row, but you don't have a whole row of them trying to tip over," he said.

Mast keeps a personal notebook full of questions, thoughts and ideas related to the new orchard. In it are notes from conversations with Extension advisors and others that he used to plan for his new orchard.

Rootstock choices

University of California Extension advisors Roger Duncan, Katherine Jarvis-Shean, and Joe Connell wrote about the importance of choosing rootstocks to improve profitability. Today there are several choices growers can pick from to address the unique challenges of individual orchards.

Mast opted on Guardian, a peach rootstock for the bulk of his 45-acre orchard. He said that was recommended for his situation – a former livestock pasture with a slight slope that became an almond orchard for the first time 25 years ago. A small segment of the previous orchard had drainage issues, which he thinks was addressed with the post-removal land preparation.

In that segment of the orchard he will use Rootpac R rootstock because of its ability to perform better in those areas where drainage and the potential for soggy soil could be an issue.

According to a UC paper written by Duncan, Jarvis-Shean, and Connell, growers are encouraged to understand their soil profile before selecting a rootstock. It is important to sample the soil profile in 12–18-inch increments to a depth of five feet, they suggest. Testing for nematodes and a complete soil chemistry analysis can be helpful in selecting the right rootstock.

Varieties

While Nonpareil almonds remain popular with growers because of their ability to capture higher prices, they require a pollinator, another variety within the orchard for cross pollination. This can also necessitate two harvest trips through the orchard. Mast did not want to make multiple harvest trips.

He opted for the newer Shasta variety from Burchell Nursery. After talking with growers who have them, he likes what he sees and hears. These self-fertile trees are promoted as needing fewer bees for pollination, another benefit towards profitability as costs continue to rise for pollination services. They are also showing promise on nut size and the ability to shake easily.

Replacing his retired orchard with almonds, rather than change crops, became easier given the large acreage of almonds where he lives in Stanislaus County. Access to processing, labor, harvest equipment, companies to repair that harvest equipment and access to the brain trust within U.C. Cooperative Extension all factored into his decision. Having 25 years of experience with the crop helped too.

"You also have to think about what the best use for this piece of property is and try to come up with something that works," he said.