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The Star Ruby Grapefruit Tree

The Star Ruby grapefruit is a wonderful fruit tree with a wide variety of uses. This fruit is known as Citrus paradisi and is renowned for its semisweet, sour, slightly bitter flesh. The first grapefruit originated as a citrus hybrid in Barbados, resulting from the crossing of a sweet orange and a shaddock (another name for a pomelo or pummelo).

Closeup of a half of a Star Ruby grapefruit on a plate.

History of the Star Ruby Grapefruit Tree

The Star Ruby is a grapefruit sport originating in Texas. Originally found as a variety of Citrus paradisi in San Benito in the 1930s, the Star Ruby was perfected by horticulturalists at the R.A. Hensz breeding program conducted at Texas A & I University in Welasco. Using the irradiated and specially bred Hudson grapefruit variety helped breed a grapefruit with fewer seeds and deeper pigments. 

Star Ruby Grapefruit Tree / Fruit Characteristics

Star Ruby grapefruits are slightly flattened, globular-shaped fruits with yellow-orange rinds and a sweet, tart flavor profile. This summer citrus tree bears fruit from mid-June to mid-September, making them a popular late summer treat to beat the heat. 

Closeup of cluster of white grapefruit tree blossoms.

The grapefruit is an evergreen that usually grows between 16 to 20 feet tall. They have been known to reach up to 49 feet, however. They produce thin glossy leaves that are dark green and up to six inches long. White four-petaled flowers grow up to two inches and eventually produce the characteristic yellow-orange fruit. Fruit is segmented and easily broken apart.

Planting Zones

Being originally a subtropical fruit, the Star Ruby grapefruit thrives in warm and tropical climates. Texas was the Star Ruby’s first home environment. These trees are now grown throughout Florida with great success. Typically, they grow well in USDA hardiness zones 9, 10, and 11. However, grapefruit trees can withstand short temperature drops as low as 25 F as long as they are already established.

Size and Spacing

Your best bet is to give each grapefruit tree plenty of breathing room. Plant saplings at least 25 but ideally 30 feet from each other. Make sure to keep fences, buildings, sheds, garages, or other structures about the same distance away, too. This helps discourage damaging insects and other pests, as well as various diseases.

Pollination

Grapefruit trees are easy to hand pollinate. That said, grapefruits are also self-pollinating! This means you have the option to pollinate or not as you see fit. Hand pollination is usually done for trees indoors or in a greenhouse. Otherwise, natural pollination by insects usually yields enough for backyard growers. If your area lacks natural pollinators such as bees, hand pollination may be necessary to pick up some of the slack.

Tree Care 

Closeup of cluster of Star Ruby grapefruits on a tree branch.

The Star Ruby Grapefruit tree is pleasant to the eye and pretty simple to care for. They grow easily and usually don’t require lots of pruning. If you plant a grafted Star Ruby, you may be able to harvest fruit as soon as two years afterward. A key component is planting your young tree after there is no longer any danger of frost. Just as important is planting early enough that high heat can’t damage your tender saplings. 

A best practice is surrounding your grapefruit tree with a few inches of organic mulch. Compost, mowed grass, leaves, and hay are all great options. Make sure not to leave mulch directly against the trunk, or you could encourage pests and disease. About 12 to 16 inches should be sufficient.

Sunlight

Star Ruby grapefruits enjoy full sun, so be sure to plant them somewhere unobstructed. It’s wise to pick the high point on your land, if you have one, to help keep it safe from cold air and excess moisture buildup. 

Watering

Water your Star Ruby tree with three to six inches of water each time you irrigate. Make sure to moisten the soil evenly about two feet deep, but make sure not to make the soil soggy or overly saturated. Water slowly and be sure to watch for when the top few inches of soil go dry. 

If there is little or no rain, every few days should be sufficient in the first five or so weeks of growth. For the next 12 weeks or so, you can likely water as little as every five days. This will depend on local climatic conditions, so use the soil as your guide.

During spring and summer, water once or twice a week. Only water two or three times a month in the fall and winter since your tree will be growing much less. 

Pruning 

The Star Ruby grapefruit requires very little pruning compared to other fruit trees. Typically, their canopies grow to be full and even largely by themselves. Use clean pruning shears to remove growth below the bud or graft throughout the year, though. Make sure you also cut away damaged or dead wood after the last frost.

Diseases 

Over-pruning grapefruit trees can cause them to develop and spread Rio Grande gummosis. Be sure to trim away any suckers that appear but otherwise do not overly prune your tree.

Pests

Closeup of Ceratitis capitata, the Mediterranean Fruit Fly, or Medfly.  This is one of the most common citrus tree pests.
The Mediterranean Fruit Fly, or Medfly, is one of the most common pests for citrus trees.

Grapefruits are prone to fruit fly infestations. Flies lay their eggs in spoiled or otherwise overripe fruits. These can easily become large outbreaks as larvae consume fruit flesh until they become pupae. Be sure to dispose of any rotting or ripened fruit to keep fly numbers to a minimum. 

Common Uses For The Star Ruby Grapefruit

Closeup of glass of pink-colored grapefruit juice with a wedge of pinkish red grapefruit next to it and in background.

The Star Ruby grapefruit stays fresh at room temperature for about a week. When refrigerated, grapefruits can last about two weeks.

What Does The Star Ruby Grapefruit Taste Like? 

The Star Ruby grapefruit tastes like the standard pink grapefruit variety. They are sweet and tart, with a vibrant tang underlying the flavor profile. Full of delicious juice and crisp red flesh, Star Ruby grapefruits are unmistakable. 

Cooking

Grapefruits are a lovely addition to salads, baked dishes, and frozen desserts. Their juice is great for making vinaigrettes and cocktail drinks. Grapefruit juices can also be cooked down for use in sauces or for making jellies, syrups, and jams. 

Eating Raw

Star Ruby grapefruit slices with slices of lemon and lime.

These grapefruits are popular as breakfast side dishes, in salads, or eaten whole. They pair well with other fruits like avocados, but especially other citruses and tropical fruits.

Star Ruby fruits are a great addition to yogurt, as a garnish for fish, or accompanying fresh herbs and greens. They’re also a fantastic addition to fruit smoothies and protein shakes. Fresh-squeezed grapefruit juice is also a popular and nutritious way to enjoy the taste of Star Ruby grapefruits. 

Canning / Freezing / Drying

Most of us haven’t had home-canned grapefruit, but it can be done! In fact, it is pretty easy to do on your own. If you’re a home canning enthusiast, make sure to try your hand at canning grapefruits. 

Grapefruit can be kept in the freezer for up to 12 months. For the best results, remove the peel and pith, then divide into segments or cut into pieces. This will keep the fruit in best condition at frozen temperatures. 

Drying grapefruit is sometimes done for candying, though you will also see it used for potpourri! 

Recipes

Grapefruit can be incorporated into many different recipes both savory and sweet. Check back often for our upcoming grapefruit recipes, including grapefruit sorbet, grapefruit relish, and spicy grapefruit margaritas. 

Health Benefits Of The Star Ruby Grapefruit

Grapefruits have many nutritional qualities that make them an excellent addition to the average person’s diet. Grapefruit is rich in vitamin C and A. They contain copper, potassium, zinc, iron, B vitamins, and dietary fiber. Star Ruby grapefruits also have the highest lycopene levels of all grapefruit varieties.

People on certain prescription medications should not regularly consume grapefruit or grapefruit juice. Grapefruit can interact with numerous drugs resulting in adverse direct and side effects. Be sure to check your prescriptions for warning labels and ask your medical caregiver before consuming grapefruit. Just one seven ounce glass or a single whole grapefruit can be enough to cause drug overdose toxicity.

Where To Buy a Star Ruby Grapefruit Tree

Star Ruby grapefruit trees can be purchased online from reputable growers like Nature Hills. These trees have been selectively bred and cultivated for the best possible results. They are grown to be aesthetically pleasing, easy to maintain, and make an abundance of seedless fruit. 

Ripe, pinkish yellow grapefruits hanging on tree branches.

Where To Buy Star Ruby Grapefruits

Fresh Star Ruby grapefruits are available in markets from the end of June to the end of September. You can often find them in grocery stores. If you live in a region where grapefruits are grown, see if you can find fresh ones at your local farmers’ market!

Conclusion

Overhead view of bowl of reddish pink grapefruit slices.

Star Ruby grapefruits are a wonderful choice for any grower looking for a unique and delicious citrus to add to their home garden. Their easy maintenance and pleasing appearance make for a great backyard tree.

With a generally large yield of delicious fruit with lots of uses, Star Ruby grapefruit trees are a great choice for fruit lovers. Growing your own fresh grapefruits has never been easier!

Do you a question or a tip to share about the Star Ruby grapefruit? Leave it in the comments section below!