Members of the Rutaceae family and Citrus genus, Kumquats are more cold hardy than other citrus
and have smaller fruit. The fruit rind is lacking citric acid, which makes it sweet and edible, but provides
less protection against insects.
Lifespan: Productive up to 50 years in a good location with proper care.
Leaf retention: Evergreen.
Growth rate: Slow.
Mature Size: 8-25' high and as wide.
Flowers: White, five petals, sweetly fragrant, borne
singly or in a cluster of three or four.
Bloom: Mid spring into fall, or throughout the year
in regions without freezes.
Self-fruitful: All Kumquat cultivars self-pollinate.
Years before fruiting: 3 years after grafting.
Fruit: Oval or round, golden yellow to reddish orange, 1" to 1.5"
diameter, sweet edible rind, tart to sweet flesh, entire fruit, except seeds are eaten. The seeds are a
source of pectin.
Months for fruit to ripen: 6, depending on cultivar and micro-climate.
The fruit are ripe when fully orange with no trace of green. They do not ripen after harvest.
Storage after harvest: At room temperature up to 3 days, or refrigerate
up to 2 weeks.
Leaves: Glossy green, ovate. Citrus leaves have a tendency to turn
pale-green or yellow in cold weather. When temperatures warm back up in the spring, the leaves will green up.
Stems: Few or no thorns. Densely branched. The bark is prone to
sunscald if not shaded by leaves, especially in higher temperatures.
Roots: Usually grafted on Trifoliate Orange (Citrus trifoliata)
rootstock because its own roots do not allow it to flourish.
Cultivars of Note:
'Large Round' / 'Meiwa' - nearly round shape, sweet thick rind
and pulp, sweetest tasting, 1.5" diameter.
'Oval' / 'Nagami' - oval shape with sweet rind and tart pulp,
unique sweet-sour flavor, eaten whole, about 1" diameter. 'Nordmann Seedless' is a variation.
'Round' / 'Marumi' - round shape, sweet rind and pulp,
intermediate sweetness between Nagami and Meiwa, 1" diameter, flesh can be dry.
'Fukushu' / 'Changshou' - a hybrid, possibly kumquat-mandarin,
less cold hardy, oval with depressed apex, 1-1.5" long, sweet rind and tart pulp, thornless, spreading
dwarf tree with larger leaves, 6-10' tall.
Wildlife: Attracts bees, butterflies, birds.
Toxic / Danger: Possible thorns.
Origin: Southeast Asia.
Cultivation and Uses
USDA hardiness zones: 8b-11.
Chill hours: None.
Heat tolerant: Less than other citrus members.
Sun: In very hot climates, afternoon shade is necessary to reduce
heat and water stress. Avoid reflected heat.
Drought tolerant: Yes.
Water after becoming established:
Every one or two weeks minimum. Deep water twice a week to maintain fruit crop. Allow soil to dry out
between waterings. Water may be needed more often in extreme heat.
Soil: Well drained, tolerate of soil types, pH 5.6-7.5
(acidic to neutral) for best results.
Fertilize: Do not fertilize the first year.
Apply an organic fertilizer every month from mid-February to late September. Apply citrus micronutrients
three times a year in February, May, and August. Do not fertilize after September to keep the plant from
producing new growth that will be harmed by early frost.
Kumquat trees are small and grow slowly, so they need less fertilizer than most citrus trees.
These trees are prone to zinc deficiency, signaled by smaller leaves, reduced shoot length and possibly
yellow blotches between green leaf veins, so application of citrus micronutrients is necessary.
Mulch: With organic material all year to reduce water loss and reduce
heat and cold stress. Keep mulch one foot away from the trunk.
Planting: Kumquat can be grown in large containers. Indoors, in cold
climates, the tree should be placed near a large, south-facing window.
First Year Care: Do not fertilize. Water at least twice a week, but
do not overwater. The soil must dry out between waterings.
Prune: Remove any suckers growing from below the graft on the trunk.
Remove crossing branches and shape in winter. If you prune up from the bottom to expose the trunk,
you should paint the trunk with tree paint to avoid sunscald.
Litter: Fruit drop.
Propagation: Cuttings grafted onto special rootstock.
Seed does not grow true and ungrafted kumquats have very weak roots that cause them to grow poorly.
The Giant Swallowtail Butterfly caterpillar. This larvae
resembles bird poop and has white and black and/or brown splotches. On a large plant it will cause no harm.
On a small plant, relocate it to a large citrus. The fruit may need to be sprayed with a garlic and Habanero
pepper mix to keep insects away. See
Citrus: Diseases and Disorders
Uses: Ornamental, edible fruit, jams, marmalade.
Former botanical name: Fortunella.
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