Grapefruits are sub-tropical to tropical citrus trees, so if you live in USDA hardiness zones 9 to 11, then you’re in luck, as growing grapefruits outdoors is possible in your area. They love heat and are a great addition to any yard being evergreen. Even if you don’t live in the perfect location, you can also choose to raise them in pots as attractive houseplants and keep them inside over winter. Let’s learn more about how to grow a grapefruit tree of your own.
What You'll Learn Today
- How To Grow A Grapefruit From A Seed?
- How To Grow A Grapefruit From A Cutting?
- How To Graft A Grapefruit Tree?
- How Long Does It Take to Grow A Grapefruit Tree?
- Do You Need Two Grapefruit Trees To Produce Fruit?
- How Many Years Does It Take For A Grapefruit Tree To Bare Fruit?
How To Grow A Grapefruit From A Seed?
It’s possible to grow a grapefruit from seed. First, you’ll need some seeds, but these can simply be taken from a ripe grapefruit.
There are several seedless grapefruit varieties so be sure to check when purchasing one from a store. The best solution may be to get some seeds from a friend or from a tree you already have growing on your property.
Once you’ve acquired some seeds, they are fairly easy to sprout and grow into young plants.
The main thing to remember here is that any tree grown from seed will not necessarily have all of the attributes of its parent plant. Like us, they are individuals with their own unique traits that are only similar but not identical to the parent.
With citrus fruits, the nucellar embryony means that the trees are often more true to type than with many other types of fruit tree, so it can be worth a gamble.
Commercially, grapefruit trees are generally propagated using bud grafting onto rootstock. There are several benefits to this over growing the trees from seed. Firstly, they are clones of their parent tree and will have all the same traits.
Secondly, they mature a lot faster and will produce fruit in a few years as compared to seven or many more for seed-grown trees.
Other options are to root some green cuttings taken from a mature tree. Again these will mature more quickly and have the same DNA as the tree they were taken from.
Because seed-grown trees can vary in quality, it is best to grow as many as you can and then select the strongest specimens to grow on into mature trees.
How To Prepare Your Grapefruit Seeds For Planting
Unlike many other types of fruit tree seeds, grapefruits don’t require any stratification.
This is where the seeds must be taken down to a cold winter-like temperature for several months to mimic a dormancy period they would naturally have over winter.
Because grapefruits grow in hot climates, their seeds don’t require this stratification process.
You’ll need to choose really ripe grapefruits to take your seeds from. Immature fruits mean immature seeds that won’t germinate well, if at all.
Prepare some small pots or seed trays and make sure they are washed and clean.
Wash the seeds thoroughly and wipe them dry afterwards. Leave them on damp kitchen paper to prevent them from drying out while you prepare everything else for planting.
If you don’t want to plant them straight away, then allow the seeds to dry and place them into a jar for later use. You’ll need to revive them by soaking them in water for 12 to 24 hours before sowing.
Sowing And Germinating Grapefruit Seeds
Although the best time of year to germinate seeds is in early spring, it can be done at any time of year, providing they are kept warm.
- Start by ensuring your chosen pots have some drainage holes in the bottom.
- Next, open your bag of soil-less potting medium. You can also create your own by mixing equal parts a) sterile garden soil, b) dampened sphagnum peat moss, c) washed all-purpose sand or dampened perlite. All of these ingredients will be readily available from any good garden store.
- Fill your pots with your potting medium and water thoroughly until saturated, allowing them to drain for a few minutes.
- Place a couple of seeds in each pot. Place them away from each other and push down so they are an equal distance below the surface of the soil as the length of the seed.
- Cover the seeds with the soil and place a small plastic bag over each pot secured around the bottom with an elastic band.
- Place the pots in a warm place or use a grow mat to keep the soil at an evenly warm temperature.
- Mist the soil to keep it slightly damp every day. Remove the bag and check the moisture level each day. If it is starting to feel dry give the pot a good misting to ensure the water penetrates down to the seedling. The soil needs to stay damp but never wet. Don’t forget to replace the bag afterward. This acts like a mini greenhouse to increase warmth and create some humidity.
- In around two or three weeks, you should see the first shoots appear. Once the first leaves have unfurled, place the pots close to a sunny south-facing window, but not in direct sunlight.
- Once the seedlings have grown several inches, transplant them into larger individual pots.
How to Transplant Grapefruit Seedlings Into Larger Pots
Your grapefruit seedlings will take several months to grow large enough to transplant.
Use sterile soilless growing medium in three or four-inch pots, or again you can make your own as shown above.
Ensure you remove the seedlings very carefully from their seed pots or trays and don’t disturb the roots at all, as they will be very delicate.
Make a large enough hole to take the entire “plug” and water thoroughly.
Be careful that they are planted to the same depth they were before and that your new pots also have drainage holes in the bottom.
Place them back close to your south-facing window, but this time allow them to receive direct sunlight for around four hours a day. Ideally, the temperature should be between 60 and 70°F.
Continue to keep the soil moist, but don’t water excessively.
Keep repotting your seedlings into slightly larger pots when they grow several inches taller.
After a year, they can safely be taken outside.
How To Move Your Young Grapefruit Trees Outdoors
You’ll need to find a bright but sheltered place to put the young trees the following spring. This helps them get used to the fluctuations in the outside temperatures.
To begin with, it’s important not to place them in direct sunlight, as this needs to be done gradually a little longer each day after the first week of acclimatization.
If there is any chance of cold weather, bring them back inside until it has passed.
Feed your trees in the spring by adding some slow-release citrus tree fertilizer to the pots as instructed on the label. Or a small handful of organic compost.
Planting Your Grapefruit Seedlings
By the third year, your seedlings will be ready to plant outside. Note that grapefruits grown from seed are not usually suited for growing in pots as they grow too large.
To discover how to plant them take a look at our article on How To Plant A Grapefruit Tree.
How To Grow A Grapefruit From A Cutting?
The most common way for grapefruit trees to be propagated is from cuttings taken from a healthy grapefruit tree of the type you want to reproduce.
The great thing about growing new trees from cuttings is that they take on the same characteristics as the parent tree, so you know what you’re going to get. This is not always the case with trees grown from seed.
Another advantage is that they will mature faster than seed-grown trees making them more attractive.
Let’s learn more about how to grow a grapefruit from a cutting:
Just like growing grapefruits from seeds, you’ll need some soil, and it is the same mixture. Sterilized soil, which you can purchase in a garden store, sphagnum peat moss, and perlite. Sterilized soil is vital as non-sterilized soil can contain pathogens that will infect and kill your cutting.
2. Prepare Your Tools
First, you’ll need to clean your cutting tool thoroughly. Wash with mild dish soap and water to remove any sticky residue that may be on the blade.
Dry it thoroughly, and just prior to cutting, wipe the blade over with a lint-free cotton cloth dipped in a little rubbing alcohol. This ensures the blade is sterile and won’t transmit any disease or fungus to your tree.
3. Taking Your Cuttings
The best time to take cuttings is after the tree has flowered and the fruits are just starting to set. This allows you to take cuttings from sections of the tree without any fruit growing on them.
Ensure any branch you select looks healthy and has plenty of leaves along its length. Or, if you’re cutting before leaves appear, there are lots of healthy-looking nodes or buds.
The cut should be made at a 45° angle.
4. Preparing Your Cuttings
If your cutting has leaves, remove all but the top three of them, but ensure to preserve the leaf stems (petioles) on the cutting.
You can cut the preserved leaves in half. This helps to direct all of the energy into growing roots while still allowing some photosynthesis to take place.
16-inch pots are a good size to start your cuttings. Fill them with your soil mixture and water well so it is good and damp before you put your cutting into the pot.
6. Rooting Hormone
To help your cuttings grow roots, you can use a rooting hormone. This comes in both powder and liquid forms.
Just before you are ready to plant your cuttings, with a small, sharp-bladed knife, scrape off about an inch of bark directly below the bottom bud or stem. If the bud or stem is further up the cutting, then shorten it.
This is because the new roots will appear at this point.
If you have powder, first dip the de-barked end of your cutting immediately in some clean water and then into the rooting powder. Knock off any excess back into the pot.
If you have a liquid rooting hormone, just dip the de-barked end in until it is covered.
It’s important to do this as soon as you remove the bark, as the area will immediately begin to oxidize, and if left too long, this will prevent root production.
7. Planting Your Cuttings
In your already prepared pots, use a stick or your finger to make a hole in the middle of the soil around 3 inches deep.
Place the cuttings in the holes – one in each pot – and gently tamp down the soil. You want the rooting hormone to stay on the cutting, so be careful not to knock it off.
8. Plastic Bag Greenhouse
To help your cutting retain moisture and keep it warm, place a clear plastic bag over the top of it and secure it around the pot with some twine or an elastic band.
Ensure the bag is tall enough not to touch the top of the cutting.
Keep the soil around your cutting damp, and don’t allow it to dry out. It also doesn’t want to be swimming in water as this will kill the roots.
10. Taking Root
In four to eight weeks, your cutting should have taken root. Once you start to see new leaves growing, you can be sure that all is going well and can grow your cutting on until the following season, re-potting it as necessary as it grows.
In this video, you can see how to propagate grapefruit tree cuttings:
How To Graft A Grapefruit Tree?
Commercial grapefruit trees are commonly propagated by grafting the desired variety onto a hardy rootstock. This gives the best of both worlds. Selecting a specific rootstock allows you to grow a tree that can be dwarf or hardy against certain problematic conditions.
The scion (cutting) used to graft onto the rootstock allows all the attributes of the parent tree to remain.
You don’t just have to use a young grapefruit tree as rootstock; you may also choose another citrus such as a sour orange seedling. Or a single branch of a mature citrus tree.
This is advantageous as grapefruit trees are prone to Phytophthora disease, where the roots and base of the tree rot from a fungus. By using a citrus that is not prone to this disease, the resulting tree will live a lot longer.
The most usual type of grafting for grapefruit is T-budding.
1. Selecting Your Scions
The cutting you take to graft must be a good fit for the rootstock you will be using.
2. Cutting Your Scions
Ensure your tools are clean and sterilized with rubbing alcohol wiped over on a lint-free cotton rag.
Cut your scions (cuttings) in spring, just after the leaves have appeared.
Make a clean, angled cut at the bottom of your chosen scion and then cut off the leaves, leaving the leaf stalk (petiole) attached to the scion.
3. Cutting Your Rootstock
Now select a place in your rootstock between two leaves and make a slit in the bark across the branch on the horizontal.
Now, in the center point of that first horizontal cut, make a vertical cut downwards of about one inch.
Gently peel back the bark slightly so it’s ready to receive your graft from the scion.
4. Creating The Sion Graft
Select a leaf stalk from the middle section of your scion that is a good fit for your rootstock. With a sharp, sterile knife, slide the blade just under the bark behind the bud to slice it cleanly off the scion.
The cut should also be around one inch in length so that it will fit neatly into the slit you have made in the rootstock.
5. Fitting The Graft Into The Rootstock
Immediately slide the leaf bud you have removed from the scion into the slit you made in the rootstock, pushing it well down and ensuring both flaps cover the leaf bud.
If you don’t do it immediately it will oxidize and the graft won’t take.
If the fit isn’t perfect, remove any excess by cutting it off neatly against the horizontal cut you made on the rootstock.
6. Securing Your Graft
With paraffin tape or grafting tape, secure the bud firmly in place so that it is held snugly together and the surfaces of each element are pushed well together.
With paraffin tape, you can wrap around the entire graft, but if using grafting tape, you will need to leave just the leaf stalk unwrapped, so it pokes out.
7. Successful Grafting
If the graft takes, it will begin to grow after several months. But leave it in place until the following season to be sure of success.
If it works, you can cut off everything that is growing above the graft, so you only have that part growing on the tree. Don’t do this until the second year to assure the health of the rootstock.
How Long Does It Take to Grow A Grapefruit Tree?
If growing a grapefruit tree from seed, it can take seven years or more before the tree will be mature enough to bear fruits.
A grafted tree or one grown from a rooted cutting will usually be mature enough within three years before the first fruits appear.
This will depend on several factors, including climate, soil conditions, water availability, nutrients, and disease.
From setting fruits, it takes, on average, nine months before grapefruits are ready to be harvested.
The varieties Melogold and Oroblanco are more tolerant of cold than most others and can be a good bet if you do get occasional frosts.
Do You Need Two Grapefruit Trees To Produce Fruit?
You don’t need two grapefruit trees to produce fruit. They are self-pollinating which means that the trees have both male and female flowers.
The pollen is spread from blossom to blossom by insects such as bees.
Despite grapefruit trees being self-pollinating, it is always better to have two or more trees as cross-pollination produces larger, more abundant fruits.
How Many Years Does It Take For A Grapefruit Tree To Bare Fruit?
As we discovered earlier, a young grapefruit tree grown from a graft or a rooted cutting will take around three years before it gives fruits. Seed-grown trees can take seven years or longer to mature enough to do the same.
Some trees will never fruit, especially if they are located in a position where they don’t receive sufficient sunlight or if the temperatures are not warm enough.
Growing your own grapefruit trees can be an excellent way of having fresh fruits available to you through late fall and winter. The longer they stay on the tree, the sweeter they become.
The easiest way for a beginner to grow a grapefruit tree is by buying a young specimen from a tree nursery or garden store.
Be sure to check that the type of tree you get will grow well and produce fruits where you live.
If you’re a little more adventurous, then you can try growing your own tree from a cutting, graft, or seed. If the parent tree is growing locally to you, then you shouldn’t have any problems with climate or soil conditions.
To learn more about growing and caring for grapefruit trees and a wide range of other fruits, head on over to our other articles.