Kumquat Tree Gardening Guide: How to Grow Kumquat Trees

A kumquat (Citrus japonica) is a flowering broadleaf fruit tree that produces a tart, orange fruit with a sweet rind. A kumquat plant produces white flowers in the late spring or early summer, which is followed by a bounty of bright orange kumquat fruit. Compared to many other citrus plants, a kumquat is rather easy to care for. It requires full sun, a warm climate, and moist, well-draining soil. Once established, it can thrive for many years.

Like many citrus trees, the kumquat plant comes in numerous varieties.

1. 1. Nagami kumquat: Also known as Fortunella margarita or oval kumquat, most kumquats found in grocery stores are Nagami kumquats. The fruit has an oblong shape and very few seeds.
2. 2. Marumi kumquat: The Marumi kumquat is round in shape. It is larger than the Nagami kumquat and somewhat less sweet. This makes it good for marmalades but less ideal for eating whole or raw.
3. 3. Meiwa kumquat: Also called Fortunella crassifolia, the Meiwa kumquat is sweeter, larger, and juicier than the standard Nagami, but it tends to be more expensive and harder to find.
4. 4. Jiangsu kumquat: Also known as Fukushu kumquat or Fortunella obovata, this kumquat plant is distinguished by its round leaves. Its fruit is popular both in raw form and in marmalades.
5. 5. Hong Kong kumquat: Known scientifically as Fortunella hindsii, this wild kumquat grows natively in the forested hillsides of Hong Kong and southern China. Its fruit is quite small and bitter, so it functions best as an ornamental plant.
6. 6. Centennial Variegated kumquat: This kumquat variety grows more compactly than a typical Nagami kumquat tree (7 to 10 feet tall as opposed to 10 to 15 feet tall). Both its fruit and leaves feature variegated colors.
7. 7. Malayan kumquat: This kumquat from the Malay Peninsula is better known by its common name, hedge lime. The fruit is similar to a limequat, which is a genetic hybrid of a kumquat and key lime.

The USDA has classified kumquats as belonging in Hardiness Zones 9–10, which means it prefers some specific conditions.

• Moist soil: Kumquats require consistently moist, loamy soil to thrive. That said, wet clay soil will likely produce root rot, so use well-draining soil.
• Slightly acidic soil: To reach the right acidity level, aim for a pH between 5.5 and 6.5.
• Full sun: Kumquat trees need plenty of exposure to bright sunlight.
• No frost: Exposure to frost can kill a kumquat tree. In Hardiness Zones 8 and below, kumquat plants must be brought indoors for the winter.

The kumquat is an evergreen tree that is native to southern China. It grows most naturally in warm, humid climates such as those in South Florida. With proper kumquat tree care, growers in any climate can house these plants indoors in pots.

1. 1. Pick a sunny location. A kumquat tree needs full sun and at least six hours of sunlight every day to thrive. If you're planting your tree outside, pick a sunny spot with loamy, well-draining soil. Avoid dense, heavy clay, which can lead to standing water and root rot. If you're potting the plant, select a pot that is at least three times as wide as the root ball and has drainage holes.
2. 2. Plant your tree at the right time. In warm climates, you can plant a kumquat tree in the late winter. Otherwise, get it in the soil by early spring for best results in its first year.
3. 3. Water and mulch regularly. To develop a healthy rootstock, keep the plant roots moist throughout the first month. Water the kumquat plant thoroughly when the soil feels dry two inches below the surface. If your plant is outdoors, put a two-inch layer of much 10 inches away from the trunk to retain moisture but prevent root rot.
4. 4. Mist and fertilize young plants. Mist the kumquat leaves regularly for the first month (at least three times per week). After one month, apply citrus fertilizer. Fertilizing occasionally during the spring and summer months will help promote a healthy root system.
5. 5. Prune as needed. Kumquat trees have shrub-like, dark green foliage, and they generally don't need much pruning. However, a gentle degree of pruning can help the plant grow thicker branches, which will help when it's time to produce fruit.
6. 6. Watch for insects. The pests that are most likely to harm a kumquat tree are aphids and mealybugs. You can mist your plant's leaves with diluted insecticidal soap or horticultural oil if you spot an outbreak.
7. 7. Don't worry about pollination. A kumquat plant is self-pollinating, so it doesn't need another kumquat tree to flower or produce fruit.
8. 8. Harvest the fruit with scissors. Most kumquat varieties produce fruit in the fall. When your kumquats are ripe, snip them from the branches using scissors. Pulling too hard on the branches can damage the plant—particularly when the kumquat tree is young. Your first year's harvest will likely be modest, but a mature kumquat tree produces a bounty of fruit.

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