In the last few articles I wrote about the many different types of fruit that can be grown in your home garden. While choices are limited due to our climate and soils, there are still some wonderful fruits worth growing here.
But of all the fruits that can be grown in the Lowcountry, there is one group that I haven’t mentioned yet. Citrus, the common name for many flowering plants within the Rutaceae family, is a group of subtropical and tropical plants that produce a wide variety of fruits. Citrus plants are some of the most rewarding fruit trees to grow. Citrus contains many wonderful fruits such as lemons, limes, oranges, grapefruits and mandarins.
Citrus fruits are a diverse and productive group of plants that, depending on the variety, tend to produce an abundance of fruits per tree each year.
The majority of citrus fruits are self-fertile, which means that only one tree is needed for pollination to take place and produce fruit. Citrus fruits generally bloom in spring but can bloom almost any time of the year depending on the weather. However, the fruits take a while to form and ripen on the tree, with citrus fruits like grapefruit taking up to 18 months to ripen.
Most citrus fruits are relatively easy to grow, but they require a consistently warm, sunny climate to thrive. They do best when grown in full sun, but can also tolerate light shade. They tolerate many types of soil, but like most of the fruit here, well-drained soil is important to prevent root rot.
Citrus grafting helps improve its cold hardness and disease resistance. Christopher Burtt / Provided
When planting citrus fruits, keep in mind that these trees are usually vegetatively propagated and not grown from seeds. The main reason for this is that citrus fruits go through a youthful phase when the tree neither blooms nor bears fruit. That’s why if you try to grow an orange or lemon from seeds, a plant can emerge, but it takes anywhere from five to 10 years to produce fruit. Citrus fruits are generally grafted onto a compatible rhizome to improve their disease resistance as well as their cold hardness. So when buying citrus trees for the home garden, be sure to buy from reputable manufacturers.
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The main limiting factor in growing citrus fruits is a lack of significant cold tolerance. The ideal temperature range for citrus fruits is between 60 and 90 degrees. However, depending on the type and variety, some have better cold tolerance for others. Kumquats are said to have the best cold tolerance as they are hardy up to temperatures of 15 degrees.
For most citrus fruits, some winter protection is necessary to avoid serious death. But even with a certain degree of death, the most important part of the tree that needs to be protected is the graft connection, the part where the desired tree or sprout is connected to the rootstock. When the plant dies due to the graft connection, only the rhizome grows back, leaving behind an undesirable citrus variety such as a three-leaved orange or a sour orange.
There are different degrees of cold hardness for each variety, so be sure to check the cold hardness for each citrus fruit you plant.
There are different types of citrus to grow, many varieties of them and a few hybrids to choose from. The varieties most frequently sold here in the Lowcountry are the lemon variety “Meyer” and the lime variety “Key”. Both are good for the home garden, but cannot be hardy and should be protected in winter. While growing oranges can be more of a challenge for our area, mandarins and calamondins do quite well, and certain varieties are quite cold tolerant. The tangerine ‘Satsuma’ is one of the best citrus trees that grow here because of its cold tolerance.
While citrus is really a wonderful world of fruit to explore, there are a few things that everyone should be aware of. One of the more serious concerns with citrus fruits is citrus greening disease, a bacterium spread by the citrus leaf insect. This insect and disease was identified in the Charleston area in 2010 and as a result the county is still under quarantine for citrus removals. The law does not allow you to bring Charleston County citrus, so use caution when buying citrus. For more information, see the Department of Plant Industries website: bit.ly/3i90iUL
There is a lot to do when it comes to citrus and I hope to be able to dwell more on this great group of fruit trees in the future. For more information on citrus, visit the Home and Garden Information on Citrus page or contact your local distributor.
Christopher Burtt is the Urban Horticulture Extension Agent and Master Gardener Coordinator for Berkeley, Charleston and Dorchester counties. He can be reached by email at cburtt@clemson.edu.
