Cumquats were once classified as Citrus but they now are accepted as belonging to their own genus Fortunella. They may be called Cumquats or Kumquats. Both spellings are acceptable, with Cumquat being of British origin.
Cumquats are small evergreen trees that can grow up to 3 metres tall, but generally much less when grown in pots. They have dark green foliage and, like their relatives the citrus, beautiful sweetly scented white flowers in late spring/summer. They are readily available in nurseries and can be bought with variegated leaves as well.
Many Australians only know Cumquats as a neglected pot plant inherited from Grandma, or as an ingredient of marmalade; but give that neglected pot some new potting soil and fertiliser and you may be surprised. The rewards are beautifully scented tiny white flowers in summer and then golden fruit to follow. The tiny fruit can remain hanging on the tree for a long time, so are very decorative. Some Cumquats are sweet enough to eat from the tree (skin and all) but others do need a little bit of sweetening to make them more attractive to our palates.
The fruit looks like a tiny orange. The fruit can be round, such as the Marumi Cumquat ( Fortunella japonica ), or an oval shape Nagami Cumquat ( Fortunella margarita ), roughly 3-5 cm long and 2-4 cm wide, about the size of a thumbnail. The peel colour is generally orange, but can also be yellow to reddish. The fruit has a sweet, oily skin and can be eaten fresh but they are a bit tart for most tastes and are more generally enjoyed as preserves or brandied cumquats, and especially made into marmalade, cumquat jelly, or fruit liqueurs. Like their relatives the Citrus they contain Vitamin C, Vitamin A, Iron and Calcium.
Another variety often sold as a Cumquat is Calamondin ( Citrus madurensis ). Some nurseries sell this with a tag “Kumquat ‘Calomondin’” but they are not truly a Cumquat. The Calamondin is also called “the miniature orange”, but the only thing miniature about it are the flowers and fruit, which are about the size of a thumbnail. The tree itself can grow 2 metres or so. Flowers and both ripe orange-coloured fruit and green-coloured fruit can appear on the tree at the same time, making it very decorative indeed. The Calomondin is perhaps a hybrid of Lime x Mandarin, or Lime x Cumquat or even Cumquat x Mandarin. No-one knows for sure.
All Cumquats deserve a place in the garden, or if that is not possible in a beautiful pot on the balcony or patio.
Cumquats are also home to a number of Australian butterfly and moth caterpillars which have adapted to the introduced RUTACEAE species. Some have become pests, feeding on the foliage, including :
(Gardenia Bee Hawk)
(Corn Ear Worm)
(Yellow Peach Moth)
Flowers in Australia
(updated 1 May 2008, 28 February 2014)