Oranges and lemons can be successfully grown in the UK, and with a little effort other citrus trees, such as limes, can be grown, too.
Lemon trees, Citrus x limon, and bitter or Seville oranges, Citrus x aurantium are the easiest citrus trees to grow. Both are vigorous plants and tend to tolerate the lowest temperatures. Limes need warmer, more tropical temperatures but it’s still possible to grow them in our cooler climate.
Most orange and lemon trees will require winter protection, though new hybrids are emerging that are pushing the boundaries of citrus hardiness.
How to grow orange and lemon trees
Grow orange and lemon trees in terracotta pots in a sheltered, sunny spot such as in front of a south- or west-facing wall. They do best in high humidity. In summer, water around once a week, using rainwater if possible. Feed them weekly with liquid seaweed and a citrus fertiliser. Prune in spring, thinning out the centre of the plant so light and air can get in, and remove branches that look dried, thin, tired or lacking in vigour. Move indoors in winter, where it remains cool but frost-free.
Watch Monty Don demonstrate how to look after a lemon tree growing in a pot:
Find out how to grow lemon trees and other citrus plants, below.
Planting orange and lemon trees
It’s best to plant lemon and orange trees in pots, so you can move them in and out of the garden for summer and winter. Opt for terracotta pots when planting, as they lose moisture more quickly, so it’s harder to overwater. Good drainage is essential for all citrus trees, and they won’t thrive in waterlogged soil. Try a 1:1:1 mix of loam, leafmould and horticultural grit, or John Innes No.3 top-dressed with garden compost or well-rotted animal manure. Repot in spring every two to three years, moving to a slightly bigger pot each time. Leave a gap between the top of the pot and the top of the soil to let water pool when you water.
Watch Monty demonstrate how to repot a citrus tree:
Caring for orange and lemon trees in summer
Once your orange or lemon tree starts growing again in spring, it’s important to move it outside to as sunny a spot as possible. The important thing is to protect them from sudden temperature changes. Look out for late frost forecasts and keep some horticultural fleece handy – you’ll need it to cover and protect the new growth if frosts are predicted.
Prune in spring once it’s outside and producing new shoots. Thin out the centre of the plant so light and air can get in, and remove branches that look dried, thin, tired or lacking in vigour. Cut out any suckers that appear at the base of the plant. Trim again in September to keep plants to the desired size. Don’t worry about pruning too much, most citrus (especially lemon trees) are vigorous and will benefit from pruning by producing more flowers and fruit on their remaining, strongest branches.
On young plants, it’s best to remove fruits, as they take a lot of energy to produce. Aim to encourage the tree to bear fewer but larger fruits, until it’s more mature. Pick any ripe fruits when you move the plants indoors in autumn, and again when you move them outside again, as ripe fruit can inhibit flower production.
Watering orange and lemon trees
Orange and lemon trees do best in high humidity. In summer, water around once a week, using rainwater if possible. If only tap water is available, let the water stand for 24 hours to let any chlorine evaporate. Water sparingly in winter – once a month is usually plenty – and a thorough soaking on occasion is much better than watering little and often.
Caring for orange and lemon trees in winter
In winter, orange and lemon trees will fare best in a cool, frost-proof area such as a garden shed, cellar or unheated greenhouse. Centrally heated rooms indoors are to be avoided, which are too hot and dry. If you have little options other than a room indoors, then go for a Calamondin orange, x Citrofortunella microcarpa, which copes best with dry heat.
Growing oranges and lemons: problem-solving
- Leaf drop: this is a sign of stress through too much heat, cold, incorrect watering or a lack of humidity, but not a disaster. See if reducing watering and increasing humidity helps
- Sticky leaves: these could be a sign of citrus mealybugs or scale insects, which thrive in warm, humid conditions. They excrete sticky honeydew that in turn, sooty moulds grow on. Wash the leaves every now and then with a soapy solution, and prune to improve ventilation. Under glass, biocontrols of wasps and ladybirds are effective
- Leaf damage: larvae of citrus leaf miners bore channels in leaves. Prune in autumn, removing all damaged material
- Yellow leaves: can be a sign of red spider mite, which is best controlled with biocontrols and high humidity. Citrus may also suffer from chlorosis as they don’t tolerate lime. Draughts, low temperatures, over- or underwatering, or poor feeding can also lead to yellow leaves
Find out how to restore a lemon tree to health, in our Quick Tips video: