The joys of a semi-dwarf navel orange tree and other hardy citrus with winter fruit

In January, I recognize the blessing of living in Southern California each time I step into my backyard and see a navel orange tree laden with fruit. As winter sets in, imbibing a daily dose of juicy vitamin C packed within a seedless navel orange, is a wonderfully purifying and revitalizing January ritual, as is smelling fragrant roses from bushes that are still in bloom.

My orange tree was planted 20 years ago and is 10 feet tall. It is a semi-dwarf, meaning that a bud from a navel orange tree was grafted onto a rootstock of a species known as hardy orange (Poncirus trifoliata). It’s a rootstock that controls the growth and ultimate size of the adult tree. A semi-dwarf orange tree is the perfect candidate for a small yard since it has a compact growth habit and reaches only about 15 feet in height. It does not produce shade so you can plant other similarly sized fruit trees around it. Its legendary springtime orange blossoms have an unrivaled fragrance that migrates throughout the garden. Orange trees, once mature, are quite drought tolerant and, even in the hottest weather, I do not soak mine more than twice a month. 

Although semi-dwarf orange and other citrus trees are highly rewarding, true dwarfs are something else again. A dwarf orange tree, which is touted for its diminutive stature of only eight feet at maturity, is made possible by a dwarfing variety of hardy orange known as Flying Dragon, used as a rootstock. A dwarf navel orange tree is suitable for container growing, but more as a curiosity than for its yield of oranges, which is minimal. 

Moreover, dwarf orange trees do not do well when planted in the ground in our dry climate, although they have done quite well, along with other dwarf citrus, when planted in large orchards in the tropics. Although the yield of individual trees is still small, the presence of so many trees per acre more than offsets the discrepancy in yield between dwarf and conventional trees. Thus, an acre of dwarf orange, tangelo, lime, or grapefruit trees would yield between 50% and 200% more fruit than an acre of much larger, conventional trees.

Flying Dragon, the rootstock utilized in the creation of dwarf citrus trees, has a fascinating personality of its own. Native to northern China and Korea and hardy down to 0 degrees, It is the only deciduous citrus species, but is an enticing garden ornamental in all four seasons. During the spring, the perfumed scent of its flowers is without compare. These flowers are followed by the appearance of golf ball-sized orange fruits covered with down. The fruits are bitter but are excellent for making marmalade. In the fall, leaves turn every shade of red and gold. Fruit remains on Flying Dragon during the winter, contrasting nicely with evergreen stems and thorns, which are up to four inches long. It is these angular thorns that give the appearance of a dragon in flight. At Oklahoma State University, a long hedge of Flying Dragon has been kept at a height of three feet for many years, resulting in such a thick accumulation of leathery growth that you can walk along the top of the hedge without fear of stepping through it.

Speaking of hardy citrus with winter fruit, I would be remiss not to mention the kumquat, which can withstand cold down to 18 degrees. In fact, kumquat trees require a dose of winter cold to live up to their full potential. An advantage of kumquat trees is their manageable size, as they seldom exceed 10 feet in height. Their fruit, no more than two inches long, although somewhat tart, may be eaten whole, together with the peel. As long as you have a sunny room, you can grow kumquats indoors too. In order to get fruit, you will need to use a small paintbrush or Q-tip. Rub or brush your pollinating utensil over the center of a flower and then apply the yellow pollen that has adhered to it to the center of another flower in order for pollination, followed by fruit development, to occur.

A commonly encountered dwarf avocado variety known as Holiday can be as disappointing as a dwarf navel orange. Although the elongated foliage of Holiday is highly ornamental, it is a reluctant bearer of fruit. You may need to wait five years to see any on your tree and when they do arrive, they will be few in number. The tree also tends to sprawl so you will have to stake it to see it develop into a proper tree. On the plus side, the fruit is gigantic as compared to Hass and it is borne inside the tree, protected by surrounding foliage from sunburn.

Have you had success with a dwarf fruit tree? If so, please write me about your experience. Everyone is invited to send questions, comments, and photos to joshua@perfectplants.com.

California native of the week: Next to the California poppy, no plant put California natives on the map like fuchsia-flowered gooseberry (Ribes speciosum). The first time you see this plant in full bloom, you may not believe the glorious sight that meets your eyes, unless you pass by it during its leafless summer dormancy period, when it looks like nothing more than a clump of thorns. With our first rain, it starts growing a new crop of glossy-lobed foliage and by December’s end, flowers begin to open. And what heart-stopping flowers they are: brilliant scarlet slightly bulging tubes with long stamens, resembling miniature fuschia blooms and so crowded along the stem that they touch each other, described as “red dressed ballerinas dancing in a line” at calscape.org. To hummingbirds, these flowers are especially magnetic. Fuschia flowered gooseberry should not be watered in the summer and thus, once established and with a minimum of winter rain, it should never be watered at all. Ultimately growing up to 10 feet tall and eight feet wide in full to dappled sun, it is best suited as a background specimen due its thorniness, which discourages proximity to walkways where it could easily prick passersby. For propagation purposes, take woody cuttings and root them in water. Locally, I have spotted this native gooseberry when wandering through Franklin Canyon, a 600-acre park at the east end of the Santa Monica Mountains that is situated between Mulholland Drive and Beverly Hills.