What we grow - Biodiversity



Lemon (Citrus limon) is a fruit tree belonging to the Rutaceae family. According to genetic studies, lemon is a hybrid and derives from the cross between bitter orange and citron. Although the origins of the lemon are uncertain, it is thought that the first places where it grew are China, where it was grown before the Song dynasty (960-1279 A.D.), the Indian region of Assam and the north of Burma. According to some experts, the ancient Romans already knew lemons. The hypothesis is supported by the depictions of these fruits in some mosaics in Carthage and frescoes in Pompeii (According to other experts, it is possible that the authors of those works had imported citrus fruits or seen in their countries of origin). Around 700 A.D. the lemon spread to Persia, Iraq and Egypt. The term “lemon” derives from the Persian term “līmū”, which generically indicates citrus fruits. The first literary descriptions of the lemon are found in Arabic writings of the tenth and twelfth centuries, by Qustus al-Rumi and Ibn Jami’. Lemon trees were first used by the Arabs as ornamental plants. The first lemon crops in Europe were those of Genoa in the mid-fifteenth century. Later the lemons were introduced in America by Christopher Columbus. In 1747 the Scottish doctor James Lind recommended the use of lemon juice as a cure for scurvy. In the 19th century, the lemon began to be intensively cultivated in Florida and California.


The lemon is a tree that reaches 3 to 6 meters in height. The buds and petals are white and violet. The lemon blossoms (Zagara), typically very fragrant, appear solitary or in pairs, white in color with purple hues in the lower part. The fruit is yellow on the outside and almost colorless on the inside, spherical-oval in shape, often with a protuberance at the apex and pointed at the other end. The peel can be very rough to smooth, more or less lined on the inside with a white spongy mass called albedo. Lemons are usually grown for fruit production but the plant can be grown in pots for ornamental purposes. In a favorable climate, the lemon blooms and fructifies several times a year. Flowering lasts at least two months and the ripe fruit can wait another two months on the tree before being picked, which favors a systematic harvest. The spring flowering produces the best fruits, the harvest of which then lasts all winter, from November to April or May. The second flowering, sometimes forced in commercial plantations (For example for the production of the “Verdello” lemon, in Sicily), occurs in August and September, the fruits can be harvested from May onwards, immediately after the winter ones. Lemons are grown all over the world in countless varieties (There are some little-known varieties, which have less commercial relevance, such as the “red lemon” and the “sweet lemon”), the differences between them are in fact found mainly in the appearance while their food qualities and relative economic importance remain practically unchanged. In fact, lemons are rarely consumed as a fresh fruit. Almost all varieties are suitable for processing. Often a distinction is made between yellow and green lemons, but this is a purely commercial distinction, as the two types grow on the same tree.The green lemon is the product of summer flowering, which is often artificially induced with the absolute deprivation of irrigation of the plant in the months of June and July. In this way, fruits with a thin green skin and very juicy pulp are obtained, which can remain stored for a long time and they withstand transport and sudden changes in temperature well, so they are exported all over the world. This type of forcing stresses the tree, but it is a very advantageous practice economically, so it is generally adopted in all plantations.


From the peel, much appreciated for the production of candied fruit, essences and pectin are also extracted. The oil is extracted from the seeds and the leftovers are used in animal feed. A liqueur called “Limoncello” is produced with the peel of the lemon and is widespread all over the world. The most commonly used part of the fruit is the juice which represents up to 50% of its weight, contains 50-80 grams/liter of citric acid, which gives the typical sour taste and several other organic acids including malic acid and vitamin C. Pasteurized juice keeps preservative-free for at least one year and is used as an ingredient in various foods and drinks. Concentrated juice is instead subjected to further processing and consumed in the canning industry. In addition, a very popular drink, lemonade, a drink prepared with lemon juice, water and sugar. The essential oil of lemon is a liquid with a color ranging from yellow to green, and is mainly used in the food industry for its flavoring power and in the perfume industry. Its by-products are often used in the production of detergents. Even in pharmacology the lemon is highly appreciated and its parts used are the juice and the zest. Its use as a medication was consolidated when nothing was known about vitamins, in fact it was used as an antihemorrhagic, disinfectant, against diarrhea and to decrease blood glucose. In aromatherapy it is indicated as a refreshing, tonic for circulation, bactericidal, antiseptic, valid for lowering blood pressure, useful for eliminating warts, calluses, inflamed gums, for treating arthritis and rheumatism, varicose veins, colds, flu. It was considered indispensable in the treatment of scurvy, something well known among sailors who did not fail to stock up on lemons before any demanding voyage. It is very rich in potassium, calcium and magnesium.


Lemon is a very sensitive plant to wind and low temperatures, much more than other citrus fruits (For this reason it is very important to choose the right exposure). If temperatures drop below freezing for a prolonged period, the risk is that the lemon tree defoliates completely. Above -5°C it can also damage the wood and therefore compromise the life of the tree. The lemon tree is very delicate, so in addition to being afraid of frost, it also suffers from the scorching heat in the summer months which, if prolonged, can compromise the correct ripening of the fruit. The lemon water requirement is high and the most delicate phase in which water must not be lacking is between flowering and fruit set, as the lemon blooms several times a year. Mulching, like any other species, is very useful especially in the first years of the plant’s life, because it avoids the growth of spontaneous grass that can compete with lemon for water and nutrients. In addition, it is particularly useful for protecting the root system from the winter cold, distributing a layer of straw or bark under the organic fertilizer. The lemon does not require systematic pruning, and therefore the cuts are usually linked to special needs, such as the elimination of parts affected by diseases and to aerate the foliage.