Almond Climate & Cultivars

Growing Almonds in California: Climate & Cultivars | Rootstocks | Orchard Management | Nutrients & Fertilization | Pruning & Training

David Doll, UCCE Farm Advisor, Merced County and Carolyn DeBuse, UCCE Farm Advisor, Yolo and Solano counties: editors

Almond Climate Requirements

The almond tree, Prunus dolcis Mill., a native of central and southwest Asia, may have been cultivated in the ancient world as early as 4000 B.C. Almonds were introduced to the Central Valley of California in the 1840s where they thrived in the mild, wet winters and hot, dry summers. Few varieties of almonds are self-fertile, therefore a combination of varieties are required for a satisfactory crop. At the beginning of the almond industry in California, a number of varieties were introduced, including Nonpareil with Ne Plus Ultra and Peerless as the pollinators.  Today the standard for almond orchard planting is to alternate pollinator rows with Nonpareil rows for optimal crop production. An introduction of nematode-resistant peach rootstocks in the 1950s contributed to a significant expansion of almond acreage from 1965-1985. Major varieties currently planted in California include Nonpareil, Carmel, Monterey, Butte, Padre, and Fritz (from 2009 California Almond Almanac).
For important characteristics to consider when selecting varieties, see the "Field Evaluation of Almond Varieties" research report on the Almond Board of California Web site and the tables below:

Time of Bloom | Pollen Compatibility | Time of Maturity | Nut Removal

Susceptibility to NOW, PTB & Noninfectious Bud Failure | Marketability

Source: Almond Production Manual (1996), UC Division of Agriculture and Natural Resources.

Table 1. Time of Bloom

Almond varieties grouped by approximate bloom periods (from Table 8.1, p.52, Almond Production Manual, 1996)

Note: This table is based primarily on results of the Mission Regional Variety Trial. The numbers in the column heads indicate the days before (-) or after (+) peak Nonpareil bloom)

Table 2. Pollen Compatibility

2a. Pollen-incompatibility groups of almond varieties (from Table 8.2, p.53, Almond Production Manual, 1996).

*Jefferies is a mutation of Nonpareil and should belong to the Nonpareil compatibility group. However, field experience combined with controlled tests in 1984 and 1985 show that Jefferies possesses unilateral incompatibility. All varieties – including the parent Nonpareil – can fertilize Jefferies. But Jefferies is unable to fertilize Nanpareil, Carmel. Solano, Monterey and all varieties in these incompatibility groups, as well as Butte. In the other hand, Jefferies can fertilize all varieties in the Mission, Ne Plus Ultra, and Thompson groups, as well as Fritz.

2b. Varieties tested for pollen incompatibility, for which no separate incompatibility group has been identified (from Table 8.3, p53, Almond Production Manual, 1996).

*If a variety in a known incompatible group is listed as compatible, then any other variety in that group should also be compatible.

Table 3. Almond Varieties' Time of Maturity

Almond varieties' time of maturity/readiness for harvest (from Table 8.4, p.54, Almond Production Manual, 1996)

*Indicates approximate number of days after Nonpareil maturity.
†LeGrand may harvest better at an earlier date (or double harvest may be helpful).

Table 4. Susceptibility to navel orangeworm, peach twig borer, and noninfectious bud failure disorders.

4a. Industry reject levels for several varieties in the 1980s (from Table 8.7,  p.56, Almond Production Manual, 1996).

Rejection rates. Low: <2%; Medium:2-4%; High: >4%.

4b. Varieties affected by non-infectious bud failure and the severity of this disorder (from Table 8.8,  p.56, Almond Production Manual, 1996).

†Not observed for the following varieties: Butte, Padre, Sonora, Ne Plus Ultra, Fritz, Monterey, Mono
*Insufficient data for rating.

Table 5. Ease of Nut Removal

Relative ease of nut removal for almond varieties (from Table 8.5, Almond Production Manual, 1996)

*Fritz matures very late and is difficult to knock if harvest is attempted too early
†Mission is harder to knock as a young tree

Table 6. Marketability

For more information go to: http://www.almondboard.com/Handlers/Documents/Almond-Varieties.pdf

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