Kumquats and calamondins

Small orange fruits, often eaten whole, and a compact plant the RHS singles out for preserves.

Britannica treats the kumquat as genus Fortunella, evergreen shrubs or trees of the family Rutaceae, grown for their tart orange fruits. Britannica The RHS describes the kumquat (Citrus japonica, AGM) as having oval orange fruits with sour flesh and a sweet rind. RHS

Native to eastern Asia, these small trees are cultivated throughout the subtropics. Britannica Kumquat fruits may be eaten fresh, or they may be preserved and made into jams and jellies. In China they are frequently candied. Britannica Kumquat plants reach about 2.4 to 3.6 metres (8 to 12 feet) high. Britannica The bright orange-yellow fruit is round or oval, about 2.5 cm (1 inch) in diameter, with mildly acid juicy pulp and a sweet, edible, pulpy skin. Britannica

The oval, or Nagami, kumquat (Fortunella margarita) is the most common species, native to southern China. Britannica The egg-shaped Meiwa kumquat (F. crassifolia) has both pulp and rind that are sweet, and is widely grown in China. Britannica

Kumquats often need 7 degrees C (45 degrees F) or more. RHS Only kumquats, with their much smaller fruits and bushy style of growth, can successfully carry a heavy crop without any need for thinning. RHS

The RHS notes that calamondins make attractive plants and the fruit is great in preserves. RHS Calamondin oranges need at least 13 degrees C (55 degrees F). RHS