Kumquat

Kumquats are small fruit-bearing trees that belong to the same family as oranges. They look a lot like oranges but are much smaller, about the size of a large olive. Kumquats grow naturally in southern China, but people have been growing them for many years in Japan and Southeast Asia. These trees can survive in cooler weather better than many other citrus trees.

Scientists sometimes disagree about how to group kumquats into species. In the past, they were called Fortunella, but now they are usually considered part of the Citrus group. Recent studies show there are three main types of kumquat trees, with one type being a mix of two others.

Etymology

The word "kumquat" comes from the Cantonese language. In Cantonese, it is called gām gwāt, which means "golden orange." This name reflects the fruit's beautiful golden color and orange-like appearance.

Description

Kumquat plants have smooth branches and very shiny leaves. They produce delicate white flowers that grow in groups or alone among the leaves. These plants can grow to be about 2.5 to 4.5 meters (8 to 15 feet) tall, with thick branches that sometimes have tiny thorns.

They produce small, yellowish-orange fruits that are oval or round. These fruits are about 2.5–5 centimeters (1–2 inches) wide. The skin of the fruit is sweet, while the inside is a bit sour. People often eat the whole fruit, enjoying its mix of sweet and sour flavors. Kumquat trees can pollinate themselves, meaning they don’t need another tree to help them make fruit (self-pollinating).

Species

The way scientists group kumquats is complex and still being studied. Some scientists think all kumquats belong to one group, while others believe there are several different groups. In the past, kumquats were considered part of the same group as oranges, but now some scientists think they should have their own special group.

One study from 2022 looked closely at many types of kumquats and found reasons to separate them into two main groups. One group has a wild type found in Hong Kong, and the other includes the types people usually grow. Inside this second group, there are several types that are quite different from each other, almost like different kinds of fruits.

Hybrids

Main article: Citrofortunella

Kumquats can mix with other fruits to make new types, called hybrids. Some of these include:

• Calamansi: made from a mandarin orange and a kumquat
• Citrangequat: made from a citrange and a kumquat
• Limequat: made from a key lime and a kumquat
• Mandarinquat: made from a Satsuma mandarin and a kumquat
• Procimequat: made from a limequat and a kumquat
• Sunquat: made from a Meyer lemon (maybe) and a kumquat
• Yuzuquat: made from a yuzu and a kumquat

Origin and distribution

The kumquat tree comes from southern China. People in China first wrote about kumquats in the 12th century. For many years, people have grown kumquats in East Asia, South Asia, and Southeast Asia. In 1846, a man named Robert Fortune brought kumquats to Europe for the London Horticultural Society, and since then, they have grown all around the world.

Cultivation

Kumquats are stronger than other citrus fruits like oranges. Planting seeds in the spring is best because the weather is nice, with more chances of rain and sunshine. This also gives the tree time to grow well before winter. Early spring is the best time to move a small tree to a new place. Kumquats need lots of sunlight, about 6 to 7 hours a day, and grow best when planted directly in the ground. They grow well in warm places, such as USDA hardy zones 9 and 10, and can survive in very cold temperatures, as low as 18 degrees Fahrenheit (−8 degrees Celsius). When trees are old enough, kumquats will grow in about 90 days.

In the UK, Citrus japonica has received a special award from the Royal Horticultural Society for being a good garden plant.

Kumquats do not grow well from seeds, so they are usually grown using parts of another citrus plant, special cutting methods, or pieces taken from other trees.

The Nordmann seedless is a type of Nagami kumquat without seeds. It looks similar to Nagami but has a slightly different shape and lighter skin.

The C_entennial Variegated_ is another type of Nagami kumquat. Its fruits change color from striped light green and yellow when not ripe to orange when ripe. These fruits are oval-shaped, about 2.5 inches long, and have smooth skin. They ripen in winter. This type produces more fruit compared to its skin and has rounder fruits that sometimes have a neck. The fruits can be recognized by their bright green and yellow stripes and lack of thorns.

The Puchimaru kumquat is a Japanese type that usually has no seeds. It resists certain plant diseases. The fruit weighs between 11 and 20 grams and is shaped like an oval. It has a dark orange skin that is 4 millimeters thick. The juice inside is not very much, and the oil spots on the skin are large and easy to see. The fruit ripens in January.

Uses

Kumquats are mostly water, with some carbohydrates, protein, and a little fat. They give you a good amount of vitamin C and have energy you can eat.

The skin of a kumquat has special oils that give the fruit its smell and flavor. These oils include something called limonene and a few other compounds that make the kumquat taste spicy and a bit woody. There are also some other chemicals that help give kumquat its unique taste.