Repot indoor citrus in spring, once roots show through the holes in the base, and move to a pot only slightly larger than the rootball. The RHS: How to grow citrus says to use peat-free citrus compost, or a soil-based compost such as John Innes No 2 or No 3 with about 20 per cent sharp sand or grit, and to top-dress between repottings. It adds that a newly bought plant can often stay in its pot for several years.
Citrus are less forgiving of a wrong repot than most houseplants because the RHS names overwatering and root rot as their main indoor failures, and a pot that is too big holds water around the roots. This guide gives the signs that a tree needs a new pot, how big the step up should be, which mix to use, how to handle a tree that cannot go in a bigger pot, and what to do if root rot has started.
When to repot
The sources agree on spring. The RHS: How to grow citrus says to repot in spring, the RHS: How to repot a plant says to avoid autumn and winter, when fresh compost can stay too wet, and Illinois Extension: Repotting says repotting is best when the plant is actively growing, typically spring or early summer. Clemson HGIC: Indoor plants, repotting adds that you should not repot ailing or dormant plants, or those beginning to flower.
The UC Master Gardeners of San Luis Obispo County: Growing Citrus in Pots give a timing detail specific to citrus: repot every few years to replace depleted soil, ideally when the tree is not flowering or fruiting heavily. That is a practical way to avoid losing a crop.
Signs your tree needs a bigger pot
- Roots grow through the drainage holes (RHS citrus guide, Illinois Extension).
- Roots appear on the soil surface, or the soil mass is filled with roots (Illinois Extension).
- New leaves are smaller than normal (Illinois Extension).
- The plant wilts between normal waterings (Illinois Extension).
- Roots spiral around the bottom of the container, or the compost has slumped and the level has dropped (RHS repotting guide).
Note the RHS says newly bought citrus can stay in the original pot for several years, so a young tree in a small pot is not a reason by itself to repot.
How big a pot, and what to fill it with
| Source | Pot size step | Mix |
|---|---|---|
| RHS citrus guide | Only slightly larger than the rootball | Peat-free citrus compost, or John Innes No 2 or No 3 with about 20 per cent sharp sand or grit |
| RHS general repotting guide | No more than one third larger; for containers under 25 cm, 2.5 to 5 cm wider and deeper | Peat-free multipurpose, or loam-based mixes for long-term pots |
| Clemson HGIC | 1 or 2 inches larger in diameter | Not specified for citrus |
| UC Master Gardeners, San Luis Obispo | Small trees in 14 to 16 inch pots; larger when roots fill the pot | Commercial palm or cactus mix; never garden soil |
The RHS problems page warns against putting citrus in a container much larger than the rootball, and the Clemson page says not to add a layer of clay pieces or rocks at the bottom. The UC guide adds that the pot should be raised so its base sits at least half an inch above the surface to drain. The sources differ on mix: the RHS wants a soil-based or citrus compost with about 20 per cent grit, while the UC guide recommends palm or cactus mix. Both aim at fast drainage.
Step by step
- Water lightly the day before if the compost is very dry, because the RHS says dry compost can make lifting the plant out easier.
- Lift the tree out gently and check the roots.
- If roots spiral, tease them out and trim lightly. Illinois Extension says to cut or unwind circling roots.
- Add fresh compost to the base so the top of the rootball sits just below the rim (RHS), or within 1 inch of the container top (Clemson). Replant at the same depth as before (Illinois Extension).
- Backfill with compost and press gently with your fingers, without packing it (Clemson).
- Water thoroughly until water shows at the drainage holes (RHS), repeating if the mix contains peat (Clemson).
If the tree cannot go in a bigger pot
For a tree already in the largest pot you can manage, the RHS gives two options. Repotting into the same container with fresh compost, you can prune off up to a quarter of the outermost roots. Where the container size cannot change at all, a light trim of up to 15 per cent of the root system every few years is often enough. The RHS also says to top-dress between repottings by replacing the top layer of compost, and Clemson says that for plants impossible to repot, you can remove the top 2 or 3 inches of soil and replace it with fresh mix every other year or so.
If roots are rotting
The RHS problems page says overwatering is the usual cause of rotting roots in citrus, with leaf fall or yellowing as the first sign. Its advice is to cut away damaged roots with some compost and repot into a smaller container. That is the opposite of the usual move to a bigger pot, and it is a good reason to check roots before assuming a struggling tree needs more room. See Citrus Leaf Drop Indoors in Winter for the winter version of the same problem.
After repotting
The sources read give no specific rule for how long to wait before feeding a repotted citrus. The RHS says to feed from late March to October with a summer citrus feed, which overlaps with spring repotting, so follow the product label. Keep the tree in the same light and temperature for a few weeks: Spring Repotting for Flowering Houseplants covers the general routine and Citrus Fertilizer Indoors the feeding side.
What the sources do not say
No opened page gives a repotting interval specific to calamondin, kumquat or Meyer lemon. The University of California Meyer lemon page and the Santa Clara citrus page both returned errors when I tried to open them, so nothing from them is used here. The RHS also gives no percentage step for citrus pot size beyond “slightly larger”.
Frequently asked questions
How often should I repot citrus?
The RHS says a new plant can stay in its pot for several years, and the UC Master Gardeners say every few years to replace depleted soil. Roots through the holes are the practical signal.
What size pot should I use?
Only slightly larger than the rootball (RHS citrus guide), no more than one third larger (RHS general guide), or 1 to 2 inches wider (Clemson).
Can I repot in winter?
The RHS says to avoid autumn and winter, when fresh compost can stay too wet.
What potting mix is best for citrus?
The RHS says peat-free citrus compost or John Innes No 2 or No 3 with about 20 per cent sharp sand or grit, and the UC Master Gardeners recommend palm or cactus mix.
Can I cut the roots?
Yes, lightly. The RHS says up to a quarter of the outermost roots when repotting into the same container.
Sources read for this page
- RHS: How to grow citrus
- RHS: Citrus problems
- RHS: How to repot a plant
- Clemson HGIC: Indoor plants, repotting
- Illinois Extension: Repotting
- UC Master Gardeners of San Luis Obispo County: Growing Citrus in Pots
Last reviewed 25 October 2026. Written by Md. Firozur Rahman. This page gives general guidance and cannot diagnose a plant from a description; see the Disclaimer. Back to the Citrus hub.
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