How to grow a lemon tree in the UK
Updated: October 2026
A young lemon has just arrived in a 12 cm pot, about 20 to 30 cm tall, and the compost is still the nursery mix. How to grow a lemon tree in the UK, in that first season, is water, feed and a pot you do not rush to replace. Keep the roots only just moist, and leave the root ball where it is this week. The three living plants are on the [lemon tree comparison](/hub/trees-and-palms/lemon-tree). Winter temperatures sit on the [lemon tree winter](/hub/trees-and-palms/lemon-tree/sub/lemon-tree-overwintering) page, and the room is on the [indoor lemon tree](/hub/trees-and-palms/lemon-tree/sub/lemon-tree-indoors) page. We did not grow these plants in a trial.
A young lemon has just arrived in a 12 cm pot, about 20 to 30 cm tall, and the compost is still the nursery mix.
A young lemon has just arrived in a 12 cm pot, about 20 to 30 cm tall, and the compost is still the nursery mix. How to grow a lemon tree in the UK, in that first season, is water, feed and a pot you do not rush to replace. Keep the roots only just moist, and leave the root ball where it is this week. The three living plants are on the lemon tree comparison. Winter temperatures sit on the lemon tree winter page, and the room is on the indoor lemon tree page. We did not grow these plants in a trial.
Our top picks
| Badge | Product | Arrival pot | Water on listing | Sun | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Carbeth Plants Carbeth mini lemon tree | 12 cm | Moderate | Full sun | 6.7 | about £26.99 | View offer |
 Gardens4you Gardens4you lemon and orange | Diameter not stated | Not stated | Full sun | 7.4 | about £34.99 | View offer | |
| Alternative |  Carbeth Plants Carbeth gift-wrapped lemon | 12 cm | Moderate | Full sun or part shade | 6.0 | about £29.99 | View offer |
Water and feed
In summer the RHS grow guide wants rainwater and compost that stays just moist, checked daily rather than on a weekday guess. A 12 cm pot on a sunny sill can dry between breakfast and supper, so the test is a finger in the compost, not a fixed cupful. In winter you let the surface dry partly, then water with tepid rainwater, and you never leave the pot standing in the saucer.
Rainwater is what the RHS prefers. If the butt is empty, use tap water that is not icy, and switch back when you can. A pot left in the runoff rots roots faster than a slightly dry day in July.
Feed is where the RHS pages disagree, and this guide will not invent a third calendar. The grow guide says a high-nitrogen summer feed from late March to October, then a balanced winter feed from November to mid-March. The citrus problems page stops the high-nitrogen feed at mid-summer. Follow one of those two and say which.
The pot it arrived in
The plain Carbeth, B09R4RLNQH, states 20–30 cm in a 12 cm pot. The gift Carbeth, B0BT1Y4K82, is the same pot with an expected height of about 30 cm. The RHS says most new citrus can stay in the nursery pot for several years. A small pot on the doorstep is not, by itself, a reason to repot on the day the box opens.
If you do move it, the new pot should be only slightly larger. The grow guide suggests John Innes No 2 or No 3 with about 20 per cent grit. A rule of thumb is 2.5–5 cm wider than the root ball. A 12 cm pot moved into a 15 cm pot fits that idea. A 12 cm root ball dropped into a 30 cm patio pot does not. The lemon tree buying guide is where pot size is checked before you order.
Moving it outside
All three listings say full sun. The gift listing also allows partial shade. Sun on a UK patio is still not a reason to carry the plant straight from a porch into a June wind. The RHS hardening-off advice is about two to three weeks, and it does not turn a tender plant into a hardy one. You lengthen the time outside, starting with a sheltered hour, and you bring it in if a cold night is forecast. Hardening off changes the shock. It does not change the H2 rating.
The citrus grow guide adds that you may have to wait until mid-June. If your nights are still sharp in early June, wait. When autumn nights dip, the plant comes back under glass. That return, and the argument between 5°C and 10°C, belongs on the winter page.
What you might see
Scale, mealybug and red spider mite are the insects the RHS names on citrus. Scale and mealybug leave a sticky film. Red spider mite likes hot, dry air, and the leaves look dusty and faded rather than wet. This page does not give a pesticide rate. Read the label, and check it is for edible crops, before you spray anything you might later pick.
Lemon fruit can irritate skin in sunlight. The RHS species page says wear gloves when you handle it. If the plant arrives with black, mushy roots or a stem that snaps dry, contact the seller. A vet is the right call if a pet eats leaves or fruit. We do not call these plants pet-safe. The listings do not say whether these plants are grafted.
Common questions
How often should I water a lemon tree in summer?
Check the pot daily and water with rainwater when the compost is only just short of dry, so it stays moist rather than wet. A 12 cm pot in full sun can need water more than once on a hot day, and a shaded porch can wait. The test is the compost, not a weekday. In winter, let the surface dry partly, then use tepid rainwater and empty the saucer.
Should I move it out of the 12 cm pot this week?
Usually, no. The RHS says most new citrus can stay in the nursery pot for several years. The plain and gift Carbeth plants are sold in that 12 cm size, and the pair does not state a diameter. Repot when roots are tight at the holes and growth has stalled, and then only a little wider.
When can a lemon tree go outside in the UK?
Harden it off over two to three weeks, and be ready to wait until mid-June if nights are still cold. Hardening off does not make the plant hardy. All three listings ask for full sun, with partial shade also listed on the gift plant, so the outdoor place is bright and out of the worst wind. Bring it in again when autumn nights dip. The date is local. Frost is still fatal.
When does lemon tree feed change?
There are two RHS calendars, and they do not match. The grow guide keeps a high-nitrogen summer feed from late March to October, then a balanced feed from November to mid-March. The problems page stops the high-nitrogen feed at mid-summer. Follow one of those and do not average them into a private third plan.
The leaves look dusty or sticky. What is that?
Sticky leaves often mean scale or mealybug. A fine, faded, dusty look in warm dry air often means red spider mite. Isolate the new plant and identify the insect before you spray. This page does not give a dose. If you cannot tell residue from a pest, ask a nursery rather than guessing a spray onto a plant you hope to eat from.
Related pages
Sources
Public UK sources used for this comparison, last checked in October 2026.
- RHS, How to grow citrus (retrieved October 2026)
- RHS, Citrus problems (retrieved October 2026)
- RHS, Citrus × limon (retrieved October 2026)
- RHS, Meyer’s lemon (retrieved October 2026)
- RHS, Garey’s Eureka lemon (retrieved October 2026)
- GOV.UK, Issue plant passports (retrieved October 2026)
- GOV.UK, Plants that need a plant passport (retrieved October 2026)
- PDSA, Cats and essential oils (retrieved October 2026)