Jujube

JUJUBE

Ziziphus jujuba Mill.

Rhamnaceae

Common Names: Jujube, Chinese Date, Tsao.

Related Specie: Indian Jujube (Ziziphus mauritiana).

Distant Affinity: Purple Haw (Colubrina texensis), Raisin Tree (Hovenia dulcis).

Origin: The jujube originated in China where they have been cultivated for more than 4,000 years and where there are over 400 cultivars. The plants traveled beyond Asia centuries ago and today are grown to some extent in Russia, northern Africa, southern Europe, the Middle East and the southwestern United States. Jujube seedlings, inferior to the Chinese cultivars, were introduced into Europe at the beginning of the Christian era and carried to the U. S. in 1837. It wasn’t until 1908 that improved Chinese selections were introduced by the USDA.

Adaptation: The jujube can withstand a wide range of temperatures; virtually no temperature seems to be too high in summertime. Winter dormancy allows it to withstand temperatures to about -28° F, yet it requires only a small amount of winter chill in order for it to set fruit. The plant revels in summer sun and heat, with the lack of either limiting fruit production more than winter cold. Yet jujubes have fruited in the Puget Sound and low Cascade regions of Washington State as well as in Pennsylvania. Fruiting of some cultivars has also been reported in northern Florida.The Indian jujube, which is more sensitive to frost, is grown in Florida, but the fruit is considered inferior. Jujube trees are not particularly suitable for container culture, but can be grown in this manner in a large container.

DESCRIPTION

Growth Habit: The jujube is a small, deciduous tree, growing to 40 feet tall in Florida, but smaller in size in California. The naturally drooping tree is graceful, ornamental and often thorny with branches growing in a zig-zag pattern. The wood is very hard and strong. Jujube cultivars vary in size and conformation, with some being very narrow in habit and others being more widespread. One cultivar, the So, seems to be fairly dwarfing in habit. After 30 years of growth in an average site, trees can be 30 feet tall with a crown diameter of up to 15 feet. Plants send up suckers (often with intimidating spines) from their roots, and these suckers can appear many feet from the mother plant. Currently, these root suckers must be controlled by mowing or hoeing.

Foliage: The small, ovate or oval leaves are 1-2 inches long and a shiny bright green. In the autumn, the leaves turn bright yellow before falling. There are usually two spines at the base of each leaf. Some spines may be hooked while others are long daggers. Virtually thornless cultivars are known. As the growing season commences, each node of a woody branch produces one to ten branchlets. Most of these are deciduous, falling from the plant in autumn.

Flowers: The inconspicuous, 1/5 inch diameter, white to greenish-yellow flowers are somewhat fragrant and produced in large numbers in the leaf axils. The flowering period extends over several months from late spring into summer. However, individual flowers are receptive to pollen for only one day or less. Pollination needs of the jujube are not clearly defined, but appear to be done by ants or other insects and possibly by the wind. Most jujube cultivars produce fruit without cross-pollination . The jujube is well protected from late spring frosts by delayed budding until all chance of cold weather has passed.

Fruit: The fruit is a drupe, varying from round to elongate and from cherry-size to plum-size depending on cultivar. It has a thin, edible skin surrounding whitish flesh of sweet, agreeable flavor. The single hard stone contains two seeds. The immature fruit is green in color, but as it ripens it goes through a yellow-green stage with mahogany-colored spots appearing on the skin as the fruit ripens further. The fully mature fruit is entirely red. Shortly after becoming fully red, the fruit begins to soften and wrinkle. The fruit can be eaten after it becomes wrinkled, but most people prefer them during the interval between the yellow-green stage and the full red stage. At this stage the flesh is crisp and sweet, reminiscent of an apple. Under dry conditions jujubes lose moisture, shrivel and become spongy inside. Tests in Russia indicate a very high vitamin C content. The fruit has been used medicinally for millennia by many cultures. One of its most popular uses is as a tea for sore throat

CULTURE

Location: Jujubes should be given a warm, sunny location, but are otherwise relatively undemanding. Given adequate heat and sun, the trees will thrive without any special care. They should not be planted in the shade of other trees

Soils: Jujubes tolerate many types of soils, but prefer a sandy, well-drained soils and do less well in heavy, poorly drained soil. They are able to grow in soils with high salinity or high alkalinity.

Irrigation: One of the outstanding qualities of the jujube tree are its tolerance of drought conditions. Regular watering, though, is important to assure a quality fruit crop.

Fertilization: Fertilizer requirements have not been studied, but jujubes appear to do well with little or no fertilization. Light broadcast applications of a balanced fertilizer such as 8-8-8 NPK at two-month intervals during the growing season would probably speed growth. Do not fertilize until the newly planted tree has several months to get established.

Pruning: Unpruned trees produce as well as trees that have been pruned. Extensive winter pruning, however, will keep the plants in better health and produce more easily obtainable fruit.

Propagation: Most Chinese cultivars in the U.S. are grafted or budded onto a thorny rootstalk which produces many suckers from the roots. There is evidence that jujube cultivars will root on hard or soft wood cuttings. However, successes have been limited to date with this process of plant reproduction. Jujubes also can be propagated from seed, although they do not come true. Most jujube cultivars produce fruit without cross-pollination, but seeds from such self-pollination are usually not viable (such as from the Li or Lang cultivars)

Jujubes should be set out 10 to 15 feet apart since they require high light intensities for good production. Upon setting out new, bare root trees, top the plant to 3 or 4 feet and remove all side branches to leave only a whip. New, stronger branches will emerge from each bud just below the point where the old branches were pruned.

Pests and diseases: The Chinese jujube appears to have no serious disease, insect, or nematode pests in the U.S., hence, no spraying is necessary. Only the pocket gopher has shown a liking for the roots. One disease, witches broom, is prevalent in China and Korea and could be destructive to a new industry if allowed to enter into non-endemic areas.

Harvest: The crop ripens non-simultaneously, and fruit can be picked for several weeks from a single tree. If picked green, jujubes will not ripen. Ripe fruits may be stored at room temperature for about a week.The fruit may be eaten fresh, dried or candied. Fresh fruit is much prized by certain cultures and is easily sold in Chinese, Korean, Vietnamese, and Indian markets. Tree dried fruit stores indefinitely and may have good marketing potential as it dries on the tree without the use of a sulfur preservative.

SELECTED RECIPES

Jujube Cake

  • 1 cup sugar
  • 1/2 cup butter
  • 2 cups dried, minced jujube
  • 1 cup water

Bring these to a boil then set aside to cool

  • 2 cups wheat flour
  • 1 teaspoonful soda
  • 1/2 teaspoonful salt

Sift these together then add to the above mixture. Bake at 325° F

Candied Jujubes

Wash about 3 pounds dried jujubes; drain and prick each several times with a fork. In a kettle bring to a boil 5 cups water, 5-1/2 cups sugar, and 1 tablespoon corn starch. Add the jujubes and simmer, uncovered, stirring occasionally, for 30 minutes. Cool, cover, and chill overnight.

The next day bring syrup and jujubes to a boil and simmer, uncovered, 30 minutes. With a slotted spoon lift jujubes from syrup and place slightly apart on rimmed pans. Dry in oven, or in sun for about 2 to 3 days. Check fruit frequently and turn fruit occasionally until the jujubes are like the dates ones sees in the market.

Jujube Syrup

Boil syrup remaining from the Candied Jujubes, uncovered, until reduced to about 2 cups. Use over pancakes and waffles. Store in the refrigerator.

Other uses: Substitute the dried jujube wherever recipes call for raisins or dates. Dried jujubes are a wonderful snack that can be prepared without the use of any preservative as is so commonly needed for other dried fruits.

CULTIVARS

Li and Lang are the two most commonly available cultivars and were from the original introductions by Frank Meyer to the Plant Introduction Station at Chico, California. The following is a list of currently propagated cultivars, based on the fruit ripening times in southern California. As interest increases, new cultivars will be brought out of China and Russia.

Early Ripening

Li
Large, round fruit up to 3 ounces in mid-August. May be picked at the yellow-green stage. Tree is many-branched, yet narrow and upright. Best eaten fresh. Best first tree to have.

Mid Season

Ed Hegard
Very similar to the Lang and Thornless.
GA-866
An outstandingly sweet selection out of the Chico Research program. Large, elongated fruit.
Jin
An excellent elongated fruit. Very chewy when allowed to dry on the tree.
Globe
A new, Chinese introduction.
Honey Jar
Another new, Chinese introduction.
Lang
Large, pear-shaped fruit which must be fully colored to be best eating. This fruit is best to let dry on the tree. Tree is upright and virtually spineless.
Redlands #4
Collected at an old homestead in Redlands, California. Very large, sweet, round fruit.
So
A tree of most beautiful shape. At each node of the stem the branch decides to go off in a new direction. Hence, a very zig-zag branching pattern which casts a beautiful shadow in the wintertime. Tree is somewhat dwarfed.
Sugar Cane
Small to medium fruit which can be round to elongated. Extremely sweet fruit but on a very spiny plant. The fruit is worth the spines!
Thornless
Just as the name implies. Very few, if any spines occur. A fruit very similar to the Lang.

Late Season

Admiral Wilkes
Collected on a South Seas expedition in the 1840’s and planted on the Capitol grounds in Washington, D.C. Elongated fruit which has been the very last to ripen, generally in mid to late November.
Chico (GI 7-62)
Fruit is round but flattened on the bottom. Looks like small apples. Excellent either fresh or dried.
GI-1183
Another cultivar from the Chico program. Large, sweet fruit.
Sherwood
A seedling plant from Louisiana. The fruit is very dense and sweet. Tree is very narrow and upright with leaves that are weeping in habit.
Silverhill
An elongated fruit which has cropped well even in northern Florida. Virtually spineless.
Tigerstooth
Very similar to Silverhill.
Topeka
From eastern Kansas and an excellent, late cropping fruit.

FURTHER READING

  • Reich, Lee. Uncommon Fruits Worthy of Attention. Reading, Mass., Addison-Wesley, 1991. pp 139-146.

 


 


© Copyright 1996, California Rare Fruit Growers, Inc.
Questions or comments? Contact us.

Raisin Tree

RAISIN TREE

Hovenia dulcis Thunb.

Rhamnaceae

Common Names: Raisin Tree, Japanese Raisin Tree, Kenpo Nashi

Distant Affinity: Jujube (Ziziphus jujuba), Indian Jujube (Z. mauritiana).

Origin: The raisin tree is native to moist areas and mountains of China, although cultivation spread long ago to Japan, Korea and India. The plant was introduced to the West in about 1820.

Adaptation: The northern limits for winter survival and fruit ripening of the tree has not been fully determined. It is cold-hardy to about -10° F, and fruits ripen in eastern North America at least as far north as southern New York. There is a 28-year old specimen in the Asian section of the Los Angeles County Arboretum and another specimen at nearby Huntington Gardens. Raisin tree plants are not particularly suitable for container culture.

DESCRIPTION

Growth Habit: The raisin tree is deciduous and can grow to a height of 70 feet or more, but cultivated specimens typically reach a height of about 30 feet with a singular trunk and a rounded head. The lower branches frequently drop off leaving a fairly high crotch. Growth rate is moderate, perhaps a foot or two per year, more when young and less when old. Raisin trees are particularly handsome when planted in groups. The deeply fissured bark is counterpointed by gently undulating branches and overlapping leaves

Foliage: The cordate, glossy green leaves are borne alternately. They are a large (up to six inches in length), rather limp leaf which must be spread out to see its shape.

Flowers: Racemes of small self-fruitful flowers bloom in late spring. They are cream colored and compensate for their small size by being clustered together in great masses. Where summers are cool, bloom may be delayed even until the end of summer with the result that fruit does not form or ripen.

Fruit: The edible “raisins” are not a fruit at all but a short, swollen mature flower stalk or peduncle which supports the inedible seed pod. As the pod matures, the peduncle of stem attaching it to the cluster swells, becomes knobby and turns a translucent reddish brown. A pear-like flavor develops as the sugars increase, and the peduncle is ready to eat when it falls to the ground. Although the edible portions are small, close to the size of a raisin, the crop is copious. The brown pod which is actually the fruit is not used.

CULTURE

Location: Although native to partially shaded sites, full sun helps hasten flowering and ripening. When placed in a southwest corner, the tree provides summer shade and allows winter sun to pass through the bare limbs.

Soil: The raisin tree tolerates a wide range of soil conditions and thrives in sandy loam.

Irrigation: Although somewhat tolerant of drought, raisin trees do best with a regular supply of moisture.

Fertilization: Little is known about the fertilization needs of the tree, but a light to moderate fertilizing in mid-spring is probably useful.

Pruning: The tree tends to prune itself, dropping the lower branches as the tree grows.

Propagation: The seeds have an impermeable seed coat that severely inhibits germination. Several methods have been employed to get around the problem. The seed coat can be scarified by nicking it with a file, or soaking the seed in concentrated sulfuric acid for two hours. Wash the seed thoroughly with water following the acid soak. The seed can also be soaked in hot tap water (approximately 140° F) for three consecutive days. Others have had some luck with freezing the seed. After treatment, the seed are planted in potting soil, covered with clear plastic wrap and placed in bright light. Seeds should germinate within a week to a month or more. Plants grown from seed usually bear fruit within 7 – 10 years, though bearing within 3 years is possible under good conditions

The plant can also be propagated by softwood cuttings taken in late summer, and by root cuttings. Little work has been done in the area of grafting.

Pests and diseases: Raisin trees are apparently free of any significant pests and diseases. Deer will probably browse the foliage, but the roots do not seem to be attractive to gophers.

Harvest: Raisin tree peduncles do not become tasty until very late in the season. They are excellent to eat out of hand or may be used in anything where raisins are normally used. The bonus with raisin tree “raisins” is that they don’t have to be dried. They are chopped and added to fruitcake in Australia, and in China they are made into a beverage called “tree honey” that is said to neutralize hangovers.

CULTIVARS

There are no known raisin tree cultivars.

FURTHER READING

  • Reich, Lee. Uncommon Fruits Worthy of Attention. Reading, Mass., Addison-Wesley, 1991. pp 95-99.

 


.


© Copyright 1996, California Rare Fruit Growers, Inc.
Questions or comments? Contact us.

Plant Propagation Chart by Claude Sweet

This is a very wide table.  Please click on the desired plant and then scroll to the right to see all propagation possibilities.  It is also possible to sort by column headings.

PlantSeedHardwood
Cuttings
Semi-Hardwood
Cuttings
Softwood
Cuttings
GraftingAir
Layering
Root
Cuttings
Offshoots/
Division
Acerola1yes45yesyesnono
Avocado1,25554yesnono
Banana1nononononono4
Capulin Cherry1,2,4555yesyesnono
Carob1,25yes5yesyesnono
Cherimoya2nonono4nonono
Cherry of the Rio Grande1,2,4no5555nono
Citrus1,2noyesyesyesyesnono
Coffee1.45yes5yesyesnono
Feijoa4noyes66yesnono
Fig14yesyesyesyesyesno
Grumichama1,2,4555yesyesnono
Guava456yes6yesnono
Jaboticaba1nonono5yesnono
Jujube1,2no55yesyesyesno
Jujube25554.5yes6no
Kei Apple1,25yes5yesyesnono
Kiwi Fruit1,2,3yesyesyes4yesyesno
Longan1,2no55yes4nono
Loquat2no5no4yesnono
Lychee1no5yesyes4nono
Macadamia1,2noyesyes4yesnono
Malabar Chestnut1,4nononoyesyesnono
Mango2,4nonono4yes2no
Mangosteen1,2no5noyesyesnono
Miracle Fruit1545noyesnono
Monstera1,4noyes4noyesnono
Mulberry1,24yesyesyesyesnono
Natal Plum1545yesyesnono
Panama Berry1,25yes5yesyesnono
Papaya4556yesnonono
Passion Fruit4noyesyesyesyes2no
Paw Paw1,2no5noyesyesnono
Pepino Dulce154yesyesyesnono
Persimmon2,3nonono4no2no
Pineapple1no4nonononoyes
Pineapple1nononononono4
Pitomba1,2,4555yesyesnono
Pomegranate14yesyesyesyesnono
Prickly Pear1no4noyesnonono
Raisin Tree1,4no5noyesyesnono
Star Fruit1,2no55yesyesnono
Sugar Cane1yes4nonononoyes
Sunnam Cherry1,2,4yesyesyesyesyesyesno
Tamarillo45yesyesyesyesnono
Tamarind1,4no5noyesyesnono
Tree Tomato1,45yesyesyesyesnono
Wampee1,2545yesyesnono
White Sapote1,2nonono4nonono
  • 1. Used in plant-breeding programs
  • 2. Nursery rootstock production
  • 3. Requires stratification period for germination
  • 4. Common commercial method
  • 5..Very difficult; requires special procedures; variable success
  • 6. Difficult procedure used to increase valuable selections

 

Fruit Cultural Data — Z

 

Key
Chill Hours between 32°F and 45°F, less hours above 65°F
Water D = dry, W = wet, M = medium
Genus Species Common Name Harm Kill Chill Water Soil/pH
Zamia integrifolia Coontie 10°F 5°F
Zanthoxylium piperitum Japanese Pepper Leaf
Zingiber officinale Ginger 32°F -10°F W
Ziziphus jujuba Jujube, Chinese Date -30°F low W/D >=7.0
Ziziphus mauritiana Indian Jujube 25°F
Zizyphus mucronata Buffalo Thorn
Zizyphus vulgaris Chinese Date Palm

 

A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z

 


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