Both the American or common persimmon (Diospyros virginiana) and the Japanese or oriental persimmon (Diospyros kaki) need some winter cool weather to blossom and produce persimmons. American persimmons will grow in U.S. Department of Agriculture plant hardiness zones 5 through 9, but the Japanese persimmon will grow in USDA zones 7 through 10, although you need to exercise caution in selecting cultivars for Southern California’s zone 10.
Winter Chill Units
Many trees, including persimmons, need a sufficient number of hours between 32 and 45 degrees Fahrenheit to break winter dormancy and blossom. This evolved protection prevents them from blooming in an unseasonal warm spell only to have their blossoms destroyed by normal temperature drops in late winter or early spring. Northern California has 800 to 1,500 winter chill hours while Southern California has just 100 to 400 hours, requiring low-chill persimmon cultivars to yield fruit.
Japanese Persimmon Climate
Japanese persimmons typically have a chilling requirement of less than 100 hours. While they can tolerate winter temperatures of zero degrees Fahrenheit, they may break dormancy in early warm weather and be damaged by spring frosts. Temperatures as low as 26 degrees will kill the leaves. The high summer heat of desert regions can sunburn their bark and suppress their yield of persimmons.
Astringent and Non-Astringent Cultivars
Astringent Japanese persimmon cultivars have a sharp, pungent taste -- leaving a "furry" taste on the tongue -- until they are soft and ripe. They are best grown in cooler regions. You can eat non-astringent persimmons when they're hard as an apple. They like hot summers and may be slightly astringent if they're grown in cooler climates.
Low-Chill, Non-Astringent Cultivars
The California Rare Fruit Growers Association recommends low-chill, nonastringent cultivars for growing in Southern California's warm climate. They especially recommend “Suruga” (Diospyros kaki “Suruga”) for warmer climates. Large, very sweet “Suruga” persimmons are orange-red and ripen in November. CRFGA also recommends the late-ripening non-astringent cultivar “Fuyu” (Diospyros kaki “Fuyugaki”), popular in Japan, a deep orange persimmon with a sweet, mild taste and an oblong, faintly four-sided shape. The most popular non-astringent variety in California is the “Jiro” (Diospyros kaki “Jiro”), that resembles “Fuyu” but is more square. The orange-red “Jiro” has excellent flavor and quality and ripens in late October through early November.
- California Rare Fruit Growers Association: Persimmon
- Purdue University: Japanese Persimmon: Diospyros Kaki
- University of Florida Extension: Diospyros Virginiana: Common Persimmon
- Floridata: Diospyros Kaki
- University of California, The California Backyard Orchard: Tree Selection
- National Gardening Association: Persimmons
- Walterreeves.com: Persimmon - Ripening to Remove Astringency
- Photo Credit Hemera Technologies/Photos.com/Getty Images