The Wonderful Kumquat
What’s a Kumquat?
Cold and flu season is upon us, and it’s time to bring out the heavy arsenal of health care products: cough drops and syrups, tissues, hot soup, and kumquats. Wait, kumquats? What’s a kumquat?
Meet the Gam Gwat
Called cumquats in Europe, these citrus trees produce little orange fruits, about the size and shape of a large grape. They are native to the mountains of south-east China and Japan, where they were originally called by their Cantonese name “gam gwat,” meaning Golden Fruit.
Robert Fortune, a collector for the London Horticultural Society and for whom the kumquat’s genus Fortunella is named, introduced them to the west in 1846. Kumquats are unique in the world of citrus in that they are the only citrus fruit with an edible peel. They are typically just eaten whole or halved, in salads or by the handful. The seed is bitter but harmless, and can be either swallowed whole or spat out. Because of its sweet peel, it is also excellent candied or used in marmalade.
A Delicious Citrus Super Fruit
Vitamin C is well known for its ability to head off a bad cold. In the citrus family, oranges are the heavy lifter, with 53.2 mg of Vitamin C per 100 grams of fruit (that’s one large fruit, once the peel is removed). At 43.9 mg per 100 grams (73% of Recommended Daily Allowances, or RDA), kumquats have nearly as much. However, they have a lot going for them that oranges lack. This is because in kumquats, you eat the whole fruit, peel and all. As with most fruits and veggies, the outer layer is where the bulk of the nutrients are. When you peel your orange and toss those skins in the compost pile, you’re throwing away all kinds of nutrients. But when you eat a kumquat, you not only get the high amounts of vitamin C and potassium in the juicy pulp, but all the nutrition of the peel too.
So what is in the kumquat peel anyway?
- It is high in fiber (100 grams of kumquats have a whopping 6.7g, or 17% of your RDA for fiber, nearly 3 times as much as an equivalent serving of orange).
- It contains abundant anti-oxidants, including carotenes (14 times as much as an orange!), tannins, etc.
- Many healthful essential oils are found in the peel, such as limonene, which is has anti-microbial properties (naturally helping to fight those germs).
- In addition to Vitamin C, it also contains Vitamins A (25% more than an orange), Niacin (a B-Vitamin, at double the amount of an orange), and Vitamin E, all of which help remove damaging free radicals from the body and thus help to protect and heal us from infections.
- A significant amount of minerals are found in the peel, as well. 62mg of calcium (50% more than an orange), as well as copper (more than double that of an orange), magnesium (nearly 10 times), manganese (6 times), zinc (2 times), and especially iron (11 times as much as an orange!)
Kumquats require much the same care that you would give your lemon or other citrus trees (more on that here). They make ideal potted plants, or can be grown outdoors in the proper conditions. Although there are many varieties of kumquat, the Nagami is most commonly available in the U.S. A few breeders have also begun producing crosses between kumquats and mandarin oranges (mandarinquats) or limes (you guessed it - limequats).
Kumquats are among the most cold-hardy of all citrus, withstanding temperatures down to 24F. They can be grown year round outside in zone 9 and 10, but also make nice looking container plants for greenhouses in any zone. These thornless trees are rather slow growing, with a maximum possible height of 8 to 12 feet. However, they are easy to prune as a dwarf, so once they reach the size you want it is easy to keep that way. Kumquats like hot summers, which stimulate abundant flowering. Harvest the fruit when they are bright orange all over.
Once they are fully orange, they will not get any bigger or sweeter. The fruit is ready for harvest in the winter, just in time for the annual germ war!