How to Grow Grapefruit
Days to germination: Seedlings are more typical
Days to harvest: Approximately 4 years
Light requirements: Full sun
Water requirements: Regularly when dry
Soil: Well-drained and fertile, with added nutrients
Container: Not great, but dwarf varieties do exist.
Introduction
The grapefruit is actually a very modern fruit, that has only existed for a couple hundred years. It’s a hybrid of the pomelo and the sweet orange, though in some regions it is misnamed as a pomelo. Most believe that it was a natural hybrid, rather than an intentional breeding done by a gardener or fruit-grower.
The flesh inside can be pink or deeper red, depending on the variety but the outside rind is typically orange and it looks just like a large orange. Varieties known for their deep red flesh include Rio Red and Flame grapefruits.
Grapefruits tend to be sour and are usually sweetened with sugar before raw eating. Hotter climates will result in sweeter fruit. It’s a very tropical tree that will only grow successfully in zones 8 to 10.
The fruit is very high in vitamin C, and is also a great source of potassium, folic acid, fiber and vitamin A. With hardly any calories, it is very popular as a breakfast fruit, usually sprinkled with sugar. The fruit is seldom used in any cooked or baked dishes, though it is also popular juiced.
Starting Your Tree
A grapefruit tree will grow to be about 15 to 20 feet tall, though older trees can be taller than 30 feet. If you are growing more than one tree, make sure to allow for 15 to 20 feet between them. Dig a hole large enough for the entire root ball to fit comfortably and cover with loose soil.
Grapefruits are self-fertile, which means the female flowers can (and will) be pollinated by the male flowers on the same tree so you don’t need to plan an orchard of several trees just to get some fruit.
When you are buying a grapefruit seedling, it will mostly likely be a grafted tree that has one kind of branching portion but a different kind of rootstock. Don’t let that discourage you, it’s perfectly normal with many kinds of citrus trees to start with grafted trees. The fruit will produce true, based on whatever kind of tree the branching portion is from.
Tree Care
Grapefruit trees should be watered at least once a week if the weather is dry, especially when the weather is very hot. You’ll also need to water your tree weekly for the first several months after planting.
In order to produce such large fruits, the grapefruit trees need a lot of nutrients so regular fertilizings are very important. A citrus fertilizer application once a month is a good idea, or at least twice per season.
These trees don’t really need any pruning, though a little maintenance each spring won’t hurt. Trim out dead branches or any that are crowded. That should be all that’s necessary.
Containers
There are some dwarf trees available, and they can usually be grown in large planters or half-barrel sized pots. They still do better when grown outside, but some cool-region growers have gotten a few fruit with indoor plants that are kept in very sunny locations.
If you do want to grow dwarf grapefruits inside, they will do better if you are able to leave them outside during the summer months and only bring them inside during the winter.
Not only are the trees smaller, but the fruit will also be noticeably smaller with container-grown dwarf trees.
Pests and Diseases
Many insect pests are common with all citrus trees, so problems with oranges or lemons can also be found with grapefruits.
Tiny aphids and scale insects are usually found on grapefruit trees, but a mature tree won’t suffer for it unless it’s a thorough infestation. A hard stream of water can easily wash off aphids, though it won’t have any effect on tough-shelled scale. If your trees have a large population of scale, there are treatment products specifically for that.
Citrus leafminers will bore through the leaves, and you will be able to see winding little patterns on each leaf. It can get bad enough that trees will start to drop their leaves, and fruit production will suffer even if the tree survives. Areas in the southern United States are prone to leafminer damage.
If you see patches of dusty black spores, your trees may have contracted sooty canker. When on the branches, you have to cut all infected material off the tree and get rid of it safely (burning is good). Once the spores have settled in the trunk, the tree is usually untreatable. It can attack the tree when there is damage to the bark, so take care when pruning and cover any cuts with an antibacterial liquid or paint (sold at nurseries) to keep out the spores.
Harvest and Storage
The exact season for grapefruit harvest can vary by region, but the fruit is usually ripe during the winter months between October and April. Young trees will only start to have fruit after the first 3 to 5 years. Depending on the variety of grapefruits being grown, you can usually judge the ripeness by the skin color. They are ready to pick once the skin is completely yellow, but a taste-test of a few fruit can help you make that decision.
Grapefruits don’t fall from the tree when they are ripe, so don’t watch for any fallen fruit as a symptom of maturity.
The trees can be prickly or thorny, so it’s usually best to wear long-sleeves during the harvest or use a long pole to gently snip or tug the fruit free.
Any fruit that is going to be used within a few days can be stored on the counter at room temperature. For longer storage, you can keep them in the lower part of your refrigerator for 1 to 2 months. They will be juicier if you let them warm to room temperature before eating though.
December 14th, 2011 at 2:00 pm
My grapefruits are yellow and they are not very sweet. What can be done to make the fruit sweeter? Will leaving it on the tree longer help?
October 18th, 2012 at 3:15 pm
Hi,
I have 3 years old Pomelo grafted grapefruit, I fertilize and water it very often. It looks healthy.
Last year it has 2 fruits quite big, but the flesh is too dry.
What should I do to get juice flesh?
Thank and best regards
MH
March 22nd, 2013 at 5:50 pm
i just bought a grapefruit tree i lve in east texas and know nothing about gardening itsa rio red grapefruit tree i need all knowledge you can send me on this great tree thanks
August 22nd, 2013 at 12:49 pm
I ALSO LIVE IN E. TEXAS, TYLER, AND HAVE A FEW CITRUS TREES. MOST OF MINE ARE SMALL BUT DO HAVE FRUIT ON THEM. HOLLOW BACK IF YOU WANT DETAILS.
January 20th, 2014 at 3:00 pm
My grapefruit tree yields a lot of fruit . The fruit at the bottom of the tree always look great and taste great . The fruit from the middle to the top of the tree do not develop properly and the skin is rough with dark patches .what can we do differently ?
August 11th, 2016 at 11:26 pm
I have this beautiful mature grapefruit tree that produces a lot of fruit but is so sour and therefore not edible. Is there something I can do to improve the taste of the fruit? Thanks.
November 10th, 2016 at 9:22 pm
Grapefruit will germinate from a peeled seed in a moist paper towel in 4 to 14 days. Seeds are notorious in citrus for not being true to their parents, and may produce inedible fruit. 5 to 7 years is a better estimate in time from planting to harvest, some have reported them to take up to 15 years to produce. The trees cannot take freezing weather, but are more resistant to a frost than most other citrus.
@ Fred Jones : Citrus, like most fruit, put out more than they can support. You should thin the crop out to 1-2 fruit per branch so the upper ones can receive a better share of nutrients during development.
I’m in my 4th year now for 30 some potted citrus trees that I started from seed, mostly grapefruit.
January 17th, 2017 at 11:06 am
I purchased a property in Mesa AZ roughly a decade ago. It contained several citrus trees, including a mature white grapefruit tree which is now about 16 ft. tall. It gets fertilized at the rate one lb. fertilizer for each inch of trunk diameter three time per year. The fruit are relatively sweet, juicy and plentiful, but small. I prefer that the fruit be larger. Next year I will thin the fruit,as a post on this blog suggests. What else can I do?
January 19th, 2017 at 3:44 pm
Fruit is mostly water, if any fruit producing plant has inadequate water it cannot product large fruit. You live in Arizona, so perhaps it isn’t getting enough water.
April 25th, 2017 at 1:16 am
i have a grapefruit in a pot usually all the blossoms fall off now 1 has remained is now nearly the size of a tennis ball.what causes blossoms to drop.we live in Johannesburg we have winters average 20cent some frost its called central plateau.Our garden is tiny and very protected