The origin of the grapefruit, also known by the Latin name, Citrus paradisi, is somewhat obscure. It is thought that the grapefruit was first found in Barbados during the 1750’s as a mutation of the pummelo. Years later, research confirmed that grapefruit is a hybrid of a pummelo (Citrus grandis) and the sweet orange (Citrus sinensis). Originally known as “the forbidden fruit,” it wasn’t until the 1800’s that a Jamaican farmer called the fruit “grapefruit” for the grape-like cluster in which it grows on trees. During same period of time, it’s believed that grapefruit made its way to the United States in the form of seeds brought by either Spanish or French settlers to Florida. Eventually, the grapefruit made its way to South Texas, most likely by visiting Spanish missionaries.

The first reported planting of a grove in Texas was in 1893. Initial grapefruit plantings in Texas were the white varieties, followed by pink varieties. John H. Shary, a developer originally from Omaha, Nebraska, was so impressed by the small crop raised by early citrus experimenters that he felt citrus was the crop of the future for Texas. Shary, also known as the “Father of the Citrus Industry,” combined his interest in growing citrus with the latest irrigation techniques and a determination to sell valley citrus commercially. In 1914, he bought 16,000 acres of brush land and after clearing it, proceeded to grow his first crop of seeded white grapefruit.

The first commercial shipment of citrus – packed in onion crates – left the Lower Rio Grande Valley of South Texas in 1920. It was about the time of the great stock market crash in 1929 that the accidental discovery of red grapefruit growing on a pink grapefruit tree gave rise to the Texas Red Grapefruit Industry. In the late 1920’s and early 1930’s, redder bud mutations were found in numerous groves. Each new finding was named for the grower who found it.

TEXAS RED VARIETIES
Texas Red Grapefruit are sweet, juicy and tree-ripened, literally stored on the tree to the peak of perfection. Texas produces the following trademarked categories of grapefruit–look for them:

RIO STAR® CATEGORY: Combines the two reddest varieties – Rio Red and Star Ruby grapefruit. It has an overall blush on the exterior peel with a deep red interior color which is 7 to 10 times redder than the Ruby Red.

RUBY-SWEET® CATEGORY: Includes the famous Ruby Red, and other redder varieties – Henderson and Ray. Its smooth, yellow skin is naturally tinged with a reddish blush and an interior color 3 to 5 times redder than Ruby Red.

FLAME CATEGORY: Red, but not too red, with the sweet, delectable taste of the Ruby-Sweet and Rio Star. Available at certain times, normally October through May.
FREQUENTLY ASKED QUESTIONS

How do you know whether grapefruit is ripe or not? Does it depend on its color?
Early in the season the fruit may be green on the outside but perfect on the inside and ready to eat. Later in the season the fruit turns yellow or gold on the outside and this can also be a sign of maturity. Texas grapefruit often has an orange color that includes patches of a pinkish blush, almost like it has been “kissed by the sun.” Avoid fruit that is lumpy, which can indicate the fruit has over-ripened. Select citrus that is heavy for its size–that’s an indication of its juiciness.

What kind of machine do they use to get the fruit off the trees?
They don’t use a machine; they pick all the fruit from the trees by hand.

What does a grapefruit tree look like?
A grapefruit tree, when left alone, can grow has high as 40 to 50 feet. In South Texas, farmers usually keep the trees to 15 to 25 feet high, making the fruit easier to pick and ensuring a larger fruit size. The tree’s medium-sized leaves are shiny and green and cover the tree from top to bottom. You can find the grapefruit growing in clusters all over the tree (not just on the top).

How do I tell an orange tree from a grapefruit tree?
Identifying citrus varieties by their leaves can be complicated when you are looking at plants in containers because their care can have an influence on color and size–which are a couple of the characteristics you look for. In normal, well-maintained citrus trees, you will find the grapefruit leaves to be larger and a couple of shades lighter green in color. Again, lack of fertilizer or over-watering can produce the same result.

Beyond color and size, and in normal leaves, the grapefruit leaf has a larger petiole than the navel orange leaf. If that term is new to you, a petiole is a smaller second leaf between the large terminal leaf and the stem or limb to which it is attached. In a grapefruit with a main leaf spanning 2 1/2 inches in width, the petiole might be around an inch wide. A large navel orange leaf might be 1 1/4 inches wide in the middle, and the petiole would be difficult to find or not much over 1/4 inch. Color and size can vary with care and condition, but the petiole test is the most certain.

Do citrus trees go dormant every year? For how long? Why?
Citrus is a sub-tropical plant which does not actually go dormant. However, the root system becomes inactive when the ground temperatures fall below 50 degrees F. With proper conditioning by sustained cool temperatures, citrus becomes inactive, but a few days of warmth can break dormancy very quickly. Drought conditions can have the same effect, but both conditions can be very damaging when carried too far.

PICKING TEXAS CITRUS:
Look for a Texas sticker on the fruit.

Choose a grapefruit with a red-blushed skin that feels heavy for its size. Heavy fruit mean lots of juice.

Tropical Beauty Marks” or blemishes are caused by gentle breezes and don’t affect the fruit inside.

Store citrus in a cool area for up to 2 weeks or in your refrigerator for up to 6 weeks.

MEASURING TIPS:
One medium grapefruit equals:
120 calories
2/3 cup juice
1 cup bite-sized pieces
10 to 12 sections
3 to 4 tablespoons grated peel
For more information about Texas grapefruit, visit: http://aggie-horticulture.tamu.edu/citrus/grapefruit.htm

“Special Thanks” to Bexar County Master Gardener, Jack Stutts, in aiding with this informative article.

Remember, Learn and Have Fun!

David Rodriguez is the County Extension Agent-Horticulture for Bexar County. He represents Texas Cooperative Extension with the Texas A&M University System. For any landscape or gardening information, call the Bexar County Master Gardeners Hotline at (210) 467-6575, e-mail questions to mg-bexar@tamu.edu, or visit our County Extension website at http://bexar-tx.tamu.edu/ and click on Horticulture and Gardening.