Kumquat – Fortunella margarita

There are two species of Kumquat. Meiwa Kumquat (Fortune crassifolia) has 5cm (2 in) orange fruits, while ‘ the Nagami Kumquat (F. margarita) bears bright orange fruits that are oblong and about 2.5cm (1 in) across. The white flowers measure 12mm across and have the rich, sweet fragrance of orange blossom.

The Kumquat originated in China and Japan. Indeed, it used to be known as Citrus japonica. It differs slightly from typical citrus plants, but it still remains in the same Rutaceae family. The fruit is very common in both China and Japan, where it has been cultivated and eaten for many generations. The fruit are often sold in supermarkets in this country.

Both species of Kumquat are available on normal or dwarfing rootstocks. Plants grown on their own roots may grow from 1.8-7.5 (6— 25ft) tall when grown in the right climate. However, those grown on dwarfing rootstocks usually only grow to about 1.2m (4ft) high. Plants on dwarfing rootstocks are perfect for large indoor containers.Kumquat - Fortunella margarita

Unlike most citrus-type fruits, both the flesh and skin of Kumquats are eaten. The rind has a sweet flavour, while the flesh is sour-tart..

Kumquat trees require protection in all areas — they need steady high temperatures in order to fruit well. Select a south or west-facing position, preferably indoors in a sunny window. Kumquats are fragile and can suffer in all but the warmest summer weather.

Using the fruits

The fruits can be used for making marmalade and jelly, and can also be candied and perserved.

Slice the fruits thinly and add them to a fruit salad or float a few slices on the top of a refreshing drink to add a bittersweet flavour.


If you are able to buy or are given some of these fruits, save a few seeds.

Wash the flesh from the seeds, and let them dry out for two or three days. Fill a pot with soil-based seed compost to which has been added further sharp sand. Sow seeds in a shallow pot or seed pan, and cover lightly with finely sieved compost. Stand the pot in several inches of water until moisture rises to the compost surface, then remove and allow surplus to drain.

Put the pot in a plastic bag and use a twist-tie to secure the top. Place on a warm windowsill. Check the compost every 7-10 days to ensure that it has not become dry. Remove the bag as soon as the seedlings appear and place in light shade.

When the seedlings are about 5cm (2in) high, pot them separately into small pots of a soil-based potting compost. The seedlings can now be treated as mature plants.

Pests And Diseases

Red spider mites and scale insects are both pests of citrus plants and Kumquats. Large colonies of scale insects are difficult to eradicate once established.

Treatment: Scale insects can be lightly scraped off the area wiped with diluted methylated spirits, while red spider mites need to be sprayed with a suitable insecticide. Check the label to ensure that the insecticide is suitable for citrus-type fruits

and that the fruits can still be eaten safely by humans after it has been applied.


Pinch out the growing tips from young plants to encourage bushiness, and prune and trim each year to encourage good growth.

Potting: Repot plants when they fill their pots with roots, perhaps every other year when young. Old and established plants are top-dressed in spring — the surface compost is removed and replaced with fresh.

During summer, wait until the compost is starting to dry out, then water thoroughly. In winter, water even more carefully and sparingly.

Feeding: From spring to late summer feed every month with a standard liquid fertilizer. Do not feed in winter.


  • Light: The brightest position possible is needed, but do not expose it to intense sunlight and high temperatures during summer. The roots need to be kept cool. Place in bright light during winter.
  • Temperature: In a warm summer the plant can be set out on a sheltered patio, but in winter a minimum 13-16°C (55— 61°F) is needed.

Buying Tips

  • In early summer, from specialist nurseries and garden centres.
  • Buy plants which have been grown by a nursery, and are well established. Seed-raised plants may also produce good fruits.
  • Once established a Kumquat will live for many years.

The Kumquat is a member of the citrus family. It has lovely sweet-smelling flowers and fruits which resemble miniature oranges.

Sorry, comments are closed for this post.