Citrus japonica - kumquats or cumquats in Australia - are a group of small fruit-bearing hardy trees in the flowering plant family Rutaceae. The edible fruit closely resembles the orange - Citrus sinensis - but it is much smaller, being approximately the size and shape of a large olive.
They are slow-growing evergreen shrubs or small trees, from 2.5 to 4.5 meters (8 to 15 ft) tall, with dense branches, sometimes bearing small thorns. The leaves are dark glossy green, and the flowers are white, similar to other citrus flowers.
Sowing & planting
200 - 400
6 - 7
Identify my kumquat
Evergreen shrub with slow growth, the kumquat can measure 4 meters high! Its branches sometimes bear small spines. Unlike citrus fruits of the genus Citrus, it is quite hardy because it can tolerate a temperature of -10 ° C.
Its leaves are bright dark green, and pure white flowers, similar to other citrus flowers. Attention: to be able to keep it in the cold regions, it is necessary to bring it in winter in a cold greenhouse, ie in a bright place where the temperature is around 8 to 12 °! In our overheated interiors, it won't stand.
Plant my kumquat
You will plant the kumquat in pot or in topen soil. Be aware that unlike citrus fruits of the genus Citrus, kumquat is relatively hardy because it can withstand a temperature of -10 ° C, but its fruits will not bear the slightest frost!
In the open soil, plant the kumquat in full sun, sheltered from the wind, ideally against a wall, in a light soil, a little acidic and well drained. Otherwise, choose a large tray or a pot preferably in terracotta, drilled at the bottom to ensure proper drainage of water.
Place in the bottom of the pot a thick layer of gravel or clay balls equivalent to about 20% of the volume of the pot.
Make a mix of good soil, compost and medium-sized river sand. Spread a layer of this mixture at the bottom of the pot and place your kumquat there so that the graft point slightly exceeds the top of the pot, because it should never be buried. Fill vacant spaces with the mixture and tamp around the roots.
Sprinkle copiously to remove any air bubbles in the soil. Add some mixture if necessary on the surface. On the other hand, never try to cultivate it indoors, it does not support the heat of the apartments.
Water my kumquat
Did you know this? The kumquat has a way to tell you that it's thirsty.
Leaves pointed upward signify that it doesn't have enough water. On the other hand, leaves pointed downward means that there's an excess of water!
That said, during good weather, an outside potted lemon is subject to a high level of evaporation: it therefore must be watered very regularly during this season for optimal growth. The mixture should never completely dry between two watering in summer, but water should never stagnate in the container.
In winter, water even more steadily as long as the tree is bearing fruit — after, you can reduce to just once a month, leaving the substrate slightly dry between two waterings.
Repot my kumquat
A potted kumquat needs regular provisions to stay in shape!
Repot in spring about every 2 to 3 years by changing the medium as much as possible to a potting soil specially for citrus fruit or planting. Ensure that the bottom of the pot has a hole - add some gravel to the bottom for drainage.
Shelter my kumquat
Starting in autumn, bring in the pots.
Have your potted kumquat spend winter in a bright frost-free spot: the ideal temperature is between 8 and 12°C - definitely not in your living room or else resign yourself to living in these temperatures.
During winter, keep watering your tree as long as it is still bearing fruit, then you can space out the watering, letting the substrate dry slightly between them.
Put outside my kumquat
Take out your kumquat in pot for the summer, from May.
Find a spot in full sun, but sheltered from the wind that dries its leaves!
Protect my kumquat
If your kumquat is planted in open soil, but you fear a possible frost, don't hesitate to cover its base with a good layer of dead leaves for the harshest weeks.
Also wrap the stem in a thick mat (woven bulrush, cane, rye or rice straw...), held by ties. You can also cover the foliage with a wintering cover.
Fertilize my kumquat
The kumquats love of water accelerates soil leaching: therefore, it really must be fertilized — especially for potted lemons!
For a plentiful harvest, regularly provide a fertilizer rich in nitrogen and lye — you can find fertilizers appropriate for citrus fruit in stores or try with a compost. In winter, reduce the provisions to once a month. In spring, start back up with a frequency of once every two weeks.
Prune my kumquat
The kumquat does not really need a pruning, but to balance its silhouette, you can prune slightly in the spring after harvest or after repotting.
Eliminate dead or diseased branches as well as overlapping ones, to "open" the plant and allow light to penetrate.
Check on my kumquat
Watch over your kumquat in winter: if the leaves darken, it's a cold spell, and if they lighten, it's a lack of fertilizer!
The lemon can also have other troubles:
Aphids are seen with the naked eye under the leaves near the veins. Spray the leaves with soapy water or a mixture of water and olive oil which will additionally nourish your plant.
Scale insects enclose themselves in a brown shell or under a white coating on the back of the leaf against the main vein and excretes honeydew which will attract fungi.
Is the kumquat's foliage faded? Its green is becoming a silver gray? Small spider webs are forming at the ends of the leaves? Your lemon has been attacked by red spiders.
Between the scale insects and red spiders, you can moisten the foliage as a precaution several times a week with soften and unbleached water.
Mulch my kumquat
Kumquats like a soil always fresh but well drained. Their roots are mostly superficial, and they do not appreciate the presence of herbs or other plants that compete with them. Mulch, to avoid weedings, and to keep the roots cool! Pine spines made mulch will suit kumquats perfectly, but dried mowing residues will also do the trick!
Reap my kumquat
The harvest takes place from November to January. Thus, the fruits often ripen inside. Keep the ground slightly damp until you pick the last fruit.