Jujube (Ziziphus jujuba) is one of the species
which will handle salt and the vagaries of weather in southern Australia....
better than olives. Known also as Chinese Date and Tsao, it is related
to Indian Jujube (Ziziphus mauritiana) and is placed in the Rhamnaceae
family.
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 to America by the USDA.
Seedlings were introduced to Western Australia
from Asia before European occupation of the continent and have naturallised
in the Kimberley area.
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.
Growth Habit: The jujube is a small, deciduous
tree, growing to about 7-10m. 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.
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 on current season's growth. 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 thefruit ripens further.
The fully mature fruit is entirely red-brown. Shortly after becoming fully
red, the fruit begins to soften and wrinkle.
The fruit can be eaten after it becomes wrinkled,
but many people prefer them during the interval between the yellow-greenstage
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
very sweet (20% natural sugars).
Growing Jujubes
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.
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.
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.
Fertilizer requirements have not been studied,
but jujubes appear to do well with little or no fertilization. Light broadcast
applications of a balanced fertilizer during the growing season will
speed growth.
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 are
whip 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)
A single seed is inside the fruit and the dark
brown appearance and this seed gives rise to the common name, Chinese Date.
Jujubes should be set out 4-5 metres 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 willemerge 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 so no spraying
is necessary.
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. The texture and flavor more closely
resemble that of an apple than a date.
Tree dried fruit stores indefinitely and may
have good marketing potential as it dries on the tree without the use of
a sulphur preservative.
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 1.5kg dried jujubes; drain and prick
each several times with a fork (de-pipping can occur now if you intend
to do it). Bring to the boil 5 cups water, 5 cups sugar, and 1 tablespoon
corn starch (optional). Add the jujubes and simmer, uncovered, stirring
occasionally, for 30 minutes.
Cool, cover, and chill overnight.
The next day add 2 tablespoons of honey to the
saved syrup, bring it and jujubes to the 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.
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. Yum!
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. Bloom to mature to maturity is 2 to 4 months,
depending on kind and climate.
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.
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.
Medicinal uses etc
The berries are valued for their mucilage and
sugar. The Jujube is classed with the raisin, date, and fig as a pectoral
fruit, being nutritive and demulcent. It is eaten both fresh and dried.
A syrup and a tisane were formerly made from it. 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.
Further Resources
*Reich, Lee. Uncommon Fruits Worthy of Attention.
Reading, Mass., Addison-Wesley, 1991. pp 139-146
Source of trees
Perrys Nursery, McLaren Flat South Australia
ph 08 83830268
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