Kumquat Tree Care: The Complete Guide

Kumquat tree care at a glance

Kumquats are the citrus you eat whole: sweet peel, tart center, no peeling required. The trees stay small, handle cold better than most citrus and fruit through winter, which makes them one of the best citrus trees for a pot. Give them heat and sun in summer, steady water and regular feeding, and they'll cover themselves in bright orange fruit.

Choosing a kumquat variety

All kumquats stay compact, and a grafted tree in a pot usually tops out at 3–6 feet. The main difference is flavor.

If you want to snack on them whole, choose a Meiwa. If you plan to cook or preserve them, a Nagami gives you more tang.

Light, water and soil

Light. Give kumquats at least 6–8 hours of direct sun. They flower in the heat of summer, later than most citrus, so a hot, bright spot in summer is what sets up a big winter crop.

Water. Water when the top 1–2 inches of soil feel dry, slowly, until it runs out the drainage holes. Empty the saucer so the roots never sit in water. Kumquats in pots dry out fast in summer and may need water every couple of days, then much less in winter.

Soil. Use a fast-draining citrus mix or a bark-based blend like our 5-1-1 recipe, in a pot with plenty of drainage holes. Go up just one or two pot sizes at a time. In the ground, plant on a slight mound if your soil holds water.

Cold tolerance and growing indoors

Kumquats are among the most cold-tolerant citrus. Once established and resting for winter, they can handle brief dips into the low 20s°F that would damage a lemon or orange. That makes them a good in-ground choice in zones 8–11. In zone 8, cover them with frost cloth on the coldest nights.

In colder areas, grow your kumquat in a pot and bring it inside before hard freezes. It doesn't need to come in as early as a Meyer lemon, so a few chilly fall nights are fine. Indoors, give it your sunniest window and a grow light if the light is weak, and keep it away from heating vents. Ease it back outside in spring once frosts are over. For a step-by-step on the move, see moving citrus indoors for winter.

Feeding a kumquat tree

Kumquats do most of their growing and flowering in the warm months, so that's when they need the most food. Feed every 4–6 weeks from spring through late summer. Feed lighter through fall and winter while the tree is mostly resting and ripening fruit.

A good citrus fertilizer for kumquats leads with nitrogen, has moderate potassium and less phosphorus, and includes the micronutrients potted citrus run short on: iron, zinc, manganese and magnesium. Pale new leaves are often the first sign those are running low.

For a kumquat in a pot, our 3-in-1 Citrus Tree Fertilizer for Container Citrus has everything pre-measured, with slow-release NPK, trace elements and calcium plus a feeding schedule to follow. For a large tree in the ground, use the Large & In-Ground kit from the same citrus fertilizer collection.

Flowers, fruit and harvest

Kumquats bloom in mid to late summer, sometimes in more than one flush, and they're self-fertile, so one tree is enough. Indoors, help pollination along by brushing a small paintbrush through open flowers. Expect some tiny fruits to drop after bloom; the tree keeps what it can carry.

The fruit ripens from late fall through winter. A ripe kumquat is fully orange with no green and gives slightly when squeezed. Ripe fruit holds on the tree for weeks, so pick as you go, snipping the stem instead of pulling.

How to eat them: pop them in whole, peel and all. The peel is the sweet part and the flesh is tart. Roll a kumquat between your fingers first to release the oils. They're also great sliced into salads, candied, or cooked into marmalade.

Pruning: kumquats need very little. After harvest, remove dead or crossing branches and trim to keep the shape. Most kumquats are grafted, so snip off any shoots from below the graft; they often have three-part leaves and won't give you kumquats. Here's how to tell if your tree is grafted.

Common kumquat problems and fixes

Most kumquat trouble comes down to light, water or nutrition:

For more on leaf color, see the most common causes of yellow citrus leaves.

Where to get a kumquat tree

Shopping for a tree? Trees.com carries citrus trees and can add a GrowScripts kit to your order, so your tree is ready to feed from day one.

Frequently asked questions

How long does a kumquat tree take to fruit? A grafted nursery tree usually fruits within 2–3 years. Trees grown from seed take much longer.

Can you grow a kumquat tree indoors? Yes. Kumquats are one of the best citrus for pots. Give them a sunny window and a grow light in winter, and put them outside for summer if you can, since summer heat is what triggers flowering.

How cold can a kumquat tree handle? Established trees handle brief dips into the low 20s°F, more than most citrus. Young trees and potted trees are more tender, so bring pots inside before hard freezes.

How big does a kumquat tree get? In a pot, usually 3–6 feet. In the ground, often 8–10 feet, and sometimes taller over many years.

How often should I fertilize a kumquat tree? Every 4–6 weeks from spring through late summer, and lighter through winter. Our citrus fertilizer kits include a schedule.

Do you eat kumquats with the peel? Yes. The sweet peel balances the tart inside, so eat them whole.

Growing other citrus? See our Meyer lemon tree care guide and orange tree care guide. Growing calamondin too? See our calamondin tree care guide.