shrub

Kumquat

Citrus japonica

The Story

Plant Bio

Citrus japonica, the kumquat, is a dense evergreen shrub or small tree reaching six to ten feet in height, with glossy, dark green leaves that feature narrowly winged petioles. The fragrant white flowers have five petals and are borne singly or in small clusters in the leaf axils, followed by small orange fruits eaten entirely rind and all.

New foliage emerges a vibrant light green before maturing to a deep, glossy shade, occasionally accompanied by small, sharp thorns on the branches. The species is notably more cold-hardy than other citrus, surviving brief temperature drops down to 15 to 10 degrees Fahrenheit once established.

Uses & Benefits:

Provides year-round structure with dense, glossy evergreen foliage, fragrant white flowers, and bright orange winter fruit.

Produces abundant edible fruit that is consumed whole, rind included, directly from the branch.

Fragrant blossoms attract and support honeybees, native bees, and other generalist insect pollinators.

Essentials

At a Glance

Plant Type

Shrub

Height

118"

Width

98"

Light

Full Sun

Zones

8, 9, 10

Water

Medium

Humidity

High

Lifespan

Multi-decade

Native To

China

Toxicity

Non-toxic

Bloom period

Spring – Summer

In flower about 6 months of the year

Planting

How to Grow

Select a planting site in full sun receiving at least six to eight hours of direct daily sunlight.
Dig a hole twice as wide as the root ball but no deeper, ensuring the graft union remains well above the final soil level.
Backfill with well-draining loamy or sandy soil, tamping lightly to remove air pockets without compacting the root zone.
Water thoroughly at planting and apply a thick layer of organic mulch, keeping it several inches away from the trunk base.

Pro Tip

Never plant the root flare below the soil line, as deep planting traps moisture against the bark and triggers Phytophthora collar rot.

Keep It Thriving

Care Guide

Do

Water consistently during flowering and fruit development to prevent premature blossom and fruit drop.
Apply a specialized slow-release citrus fertilizer three times a year in early spring, late spring, and mid-summer.
Prune lightly immediately after harvest to shape the canopy and remove dead or crossing branches.

Don't

Do not overwater or allow the soil to become waterlogged, which rapidly induces root and collar rot.
Do not prune heavily into old, leafless interior wood, as these branches fail to resprout reliably.
Do not pile mulch against the trunk, which traps moisture and invites fungal pathogens.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fertilize
Mulch
Pest Check
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

EspalierContainer SpecimenEdible GardenEvergreen Screen

Companion Plants

Rosmarinus officinalis Lavandula angustifolia Origanum vulgare

Multiply

Propagation Methods

Good to Know

Common Questions

Kumquat questions

What zones can Kumquat grow in?

Kumquat is hardy in USDA Zones 8–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Kumquat deer resistant?

Not reliably. Deer may browse Kumquat, especially tender spring growth — plan on repellents or fencing where pressure is high.

When does Kumquat bloom?

Kumquat typically blooms in spring through summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Kumquat need full sun?

Kumquat does best in full sun (6+ hours).

Is Kumquat drought tolerant?

Yes — once established (usually after the first full season), Kumquat handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.