Citrus limetta

Citrus limon Ponderosa

Small to medium sized tree, usually to 10-25ft high. Trees are somewhat sensitive to freezes and grow best in areas having only limited frosts and freezes. The Ponderosa Lemon tends to be slightly less hardy than other lemon varieties. Grows in conditions suitable for the average citrus, water frequently except during cold months. Fertilize 2-4 times per year. Can be container grown and was historically a common lemon grown indoors in temperate climates.

Very large, bumpy skinned lemon usually weighing 2-4 pounds. Flavor is typical lemon-like.

Propagation: Commonly by grafting cuttings to various citrus rootstocks. Can also be propagated by seed which usually come true, or fairly close to their parent.

Citrus medica

Citrus medica is characterized by its thick rind and small sections. Generally, it is eaten preserved or in bakery goods, such as fruitcakes. (The candied peel rather than the fruit is often used in cooking). The citron was the first of the citrus known to the Romans. In ancient time the fruit was never eaten (it began to be used in cooking by the early 2nd century), but its intense perfume was used, penetrating clothes to repel noxious insects.

Citrus trifoliata, Poncirus trifoliata

This is the hardiest close relative of Citrus. It is a deciduous shrub armed with vicious spines and will survive temperatures as low as 0F to -10F. In the USA it certainly grows as far north as Boston, MA (Hardy for zones 5-9). The fruits are like small oranges about 1.5 inches across, very sour, but can be used in conserves and drinks. Watch it through the seasons. In spring it sports white, fragrant flowers. Its summer foliage is shiny and dark green. In autumn it sheds its leaves to show off its glossy-green stems. Fruit, which is very sour, also adds fall interest. It is a great barrier plant and can be trimmed to form a 3-foot hedge. It can also be used as a novelty specimen. It is also used as citrus rootstock.

Citrus x sinensis

Orange refers to a citrus tree (Citrus sinensis) and the fruits of this tree. It is a hybrid of ancient cultivated origin, possibly between Pomelo (Citrus grandis) and Tangerine (Citrus reticulata). It is a small tree, growing to about 30ft tall, with thorny shoots and evergreen leaves 2-4in long. The fruit originated in southeast Asia, in either India, Vietnam or southern China.

Oranges are widely grown in warm climates worldwide, and the flavors of orange vary from sweet to sour. The fruit is commonly peeled and eaten fresh, or squeezed for its juice. It has a thick bitter rind that is usually discarded, but can be processed into animal feed by removing water using pressure and heat. It is also used in certain recipes as flavoring or a garnish.