UNITED STATES—Winter is bare root season, which is the best time for installation of deciduous fruit trees. It is also the best time for dormant pruning of deciduous fruit trees. Evergreen fruit trees do not get much attention. Installation and any pruning of evergreen fruit trees happens after winter. However, regardless of perceived neglect, winter is actually citrus season.

Technically, citrus is always in season here. That is because most citrus fruits last so long on their trees after ripening. Also, some types produce a few fruits sporadically after their primary season. The latest ‘Lisbon’ lemons can still be good as the earliest of the following season ripen. ‘Eureka’ lemons ripen in minor phases after their primary phase.

Therefore, winter is citrus season merely because it is when most citrus fruit ripens. The schedule is ideal. It begins as pear and apple season finishes. It finishes as cherry and apricot season begins. Pears and apples, and especially cherries and apricots, are less predictable than citrus. Fortunately, citrus can begin a bit early or finish late if necessary.

Sweet, sour or bitter?

All citrus are species or hybrids of the same genus of Citrus. Kumquats also classify as Fortunella though. The primary components of the flavors of their fruits are sweet, sour and bitter. The most familiar oranges are sweet oranges, but sour and bitter oranges also exist. Most lemons and limes are sour, but there are also sweet lemons and sweet limes.

Oranges, which are generally sweet oranges, are the most popular citrus. Navel oranges are traditional eating oranges. ‘Valencia’ is a traditional juicing orange. Blood oranges are a bit more tart, with blushed or red flesh and juice. ‘Seville’ sour orange is useful for marmalade. Rare bitter oranges provide flavoring for teas, and fragrance for perfumery.

Lemons are the second most popular citrus. Mandarin oranges, or mandarins, should probably be more popular. They are the more perishable of citrus though, because their rinds are relatively loose. Tangerines are merely mandarins of the Americas. ‘Rangpur’ lime is a sour mandarin. Real limes are very diverse, but mostly ripen greenish yellow. Grapefruits combine sweet, sour and bitter.

Highlight: Lime

Among citrus, limes are the most diverse. They include more species and hybrids than other types of citrus. Only a few of countless cultivars from centuries of development are available here. Yet, each of these few is very distinct from the others. Most provide juice for culinary application. At least one provides herbal foliage. Few limes are eaten intact.

Dwarfing understock is one commonality of almost all home garden lime trees. Not many grow more than 12 feet tall. With occasional pruning, most might stay less than eight feet tall. All have bright green evergreen foliage and small white flowers. Most have tiny but sharp thorns. Some are more bothersomely thorny. Fruit is green or greenish yellow.

‘Bearss’ lime is the most popular. Its ripe fruits are about three inches long and resemble greenish lemons. ‘Mexican’ lime provides fruits that are about an inch and a half wide, on thorny stems. ‘Palestine’ lime is thorny also, with round and yellowish fruit that is edible intact. ‘Rangpur’ lime produces bright orange fruit because it is really a sour mandarin.

Tony Tomeo can be contacted at tonytomeo.com.