Lemon (Citrus × limon) is a small tree or spreading shrub belonging to the rue family (Rutaceae), widely cultivated for its edible and highly acidic fruits. Lemon juice is a key ingredient in many pastries and desserts, including tarts and the traditional lemon meringue pie. Its sharp, refreshing flavour, whether fresh or preserved, is also used to enhance poultry, fish, and vegetable dishes around the world. Lemonade, prepared from lemon juice, sugar, and water, is a popular warm-weather drink, while lemon juice is commonly added to tea. The fruit contains high levels of citric acid, which may account for more than five percent of its juice, and is rich in vitamin C, with smaller amounts of B vitamins such as thiamin, riboflavin, and niacin.
The lemon plant forms an evergreen, spreading bush or small tree that can grow between 3 and 6 metres tall if left unpruned. Young leaves are oval and reddish in colour before turning green, while some varieties develop angular branches and sharp thorns. The fragrant flowers grow singly or in small clusters and have white petals with purplish undersides. The fruit is oval with a small apical nipple and is divided into 8 to 10 segments. Its yellow rind is thick in some varieties and contains oil glands, while the inner white layer, known as the albedo, is the main commercial source of pectin. The pulp is juicy and strongly acidic, and the seeds are small and pointed, though some fruits are seedless.
In Kenya, the main lemon varieties grown are Eureka and Lisbon, which dominate commercial production, and Meyer lemon, which is sweeter and mainly cultivated on small farms and in home gardens. Lemon farming is concentrated in coastal counties such as Kilifi, Kwale, and Lamu, in Eastern Kenya including Machakos, Makueni, and Kitui, and in parts of Central, Rift Valley, and Western Kenya where irrigation and well-drained soils are available. These regions provide warm temperatures and moderate rainfall that support reliable fruiting throughout the year. Although official statistics often combine lemon and lime production, horticultural data indicate that about 8,000–9,000 hectares are under lemon and lime cultivation nationwide, with lemons occupying a large share due to strong local demand, processing, and export markets.
Nutritionally, lemons are an excellent source of vitamin C, which strengthens immunity and supports skin health. They also provide potassium, vitamin B6, folate, and small amounts of calcium and magnesium. Low in calories and rich in antioxidants and beneficial plant compounds, lemons aid digestion, help regulate blood pressure, reduce inflammation, and contribute to overall heart and metabolic health.