Unlike other types of fruit trees, citrus trees, including grapefruits, don’t require excessive pruning. Once the form of the tree is established when young, all that’s required is the removal of dead, damaged, or diseased branches and a small amount of tidying up. Over-pruning your grapefruit tree will be detrimental to the tree’s health and its fruit production. Read on to learn more about how to prune a grapefruit tree correctly.
What You'll Learn Today
When To Prune A Grapefruit Tree?
Grapefruit trees require pruning in the winter when they are dormant, and there is no risk of frost.
When you plant a grapefruit tree, helping it to form a strong structure to support the heavy fruits will be highly beneficial, and this is the only time when any amount of major pruning is required.
How Do You Prune A Grapefruit Tree?
Grapefruits start by forming a bush-like form and should not be pruned until they reach two feet in height.
It’s better for the tree to maintain this shape as citrus trees are closed canopy trees that should have thick foliage on their outer branches to protect the delicate bark on the trunk and branches.
Exposing the bark of a grapefruit tree can cause it to become sunburned due to the volatile oils contained in it.
This is a mistake made by many people, believing that a citrus tree should be pruned just like any other type of fruiting tree into an open shape that allows for a lot of airflow and sunlight to penetrate into the heart of the tree.
Because citrus flowers and fruits are on the outer branches, sunlight doesn’t need to penetrate inside, and airflow is achieved as there are no leaves on the inside of a mature canopy.
How To Prune A Newly Planted Tree
Stand away from your tree and look at its overall shape. Find four strong branches that are spaced around the trunk of the tree evenly and are growing outwards away from the trunk and with an open angle of around 45 degrees.
These branches should not be positioned adjacent to each other on the trunk but rather staggered, going up the trunk in more of a spiral. This is because adjacent branches can be put under too much stress when laiden with fruit and could break.
Once you’ve identified the best four or five branches, you can remove anything that is growing below them. These four or five branches are called “primary scaffolds”.
If any of the scaffold branches are excessively long, you can also tip them to reduce them to a more uniform length.
After pruning, allow the tree to grow on until the following winter.
Pruning In The First Winter After Planting
By now, your sapling should have established a strong root system and a healthy-looking foliage layer.
Now cut out any dead, broken, diseased, crossed, downward, or inward pointing branches and twigs.
Then look at the shape of the tree and trim it to get an attractively even-shaped canopy, so there aren’t any long branches growing off to one side and so on.
Keeping the shape of the tree even and symmetrical when young is important, as once it begins to favor growth on one side, it will continue to do so.
Remember you never want to cut back more than 20% of the tree.
Flower And Bud Pruning
Should your young grapefruit tree produce any flowers in the first couple of years, it’s better to remove them along with developing buds so that it can focus all of its energy on growing strong roots and branches.
Pruning A Mature Grapefruit Tree
Once your tree reaches three years old, you should limit the amount of pruning you do each year and allow a good canopy to form.
From now on, pruning is no longer done for the benefit of the tree so much as for the gardener.
The form of the tree you created while it was young should have created a strong scaffolding of branches that can support the heavy weight of the grapefruits.
Pruning now involves removing dead or diseased branches from within the canopy. You can also remove any suckers growing from below the graft point on grafted trees, or branches that are less than a foot from the ground.
You don’t want any branches to touch the floor, as this can promote problems with disease and pests.
The canopy of the tree should be closed so that sunlight cannot penetrate the inner tree.
Fruits are born on the outer branches, so access to light is not a problem.
Inside the canopy, you can open up the branches by removing small twigs or dead wood, plus any suckers that are growing beneath the scaffold branches of the tree.
In this video, you can learn more about pruning citrus trees that are growing in cooler climates:
How To Prepare Your Pruning Tools
It may seem surprising, but disease can easily be spread through your grapefruit tree if you don’t keep your cutting tools clean.
Disease present in one limb of the tree may be transmitted to other healthy branches by contaminated cutting blades.
It isn’t always apparent that disease is present, so it’s a wise precaution to wipe the cutting blades with rubbing alcohol between cuts when moving from branch to branch.
Tools Required For Pruning
- Hand pruners
- Long-handled pruning shears
- Pruning Saw
- Garden gloves
- Rubbing alcohol
- Clean, lint-free cotton rags
- Pruning sealer
First, ensure your cutting tools are clean and sharp. Dirty, dull tools will damage your tree by spreading disease and crushing rather than cutting the branches leaving ragged cuts that can allow pathogens to enter.
Gloves keep your hands from becoming scratched by thorns and from getting splinters. You can also get a better grip on the branch with gloves on.
When sawing, depending on the size of the branch, do so downwards and at an angle away from you to make a clean cut. If, for some reason, you have to cut off a larger limb due to damage or disease, then cut 1/3 of the way upwards through the branch and then downwards to meet the first cut.
If you remove branches of more than one inch in thickness, apply some pruning sealer to prevent disease from getting into the tree.
Pruning Emergencies
If you notice that your grapefruit tree is showing signs of disease during the flowering or fruiting season, then it’s best to act immediately to prevent further spread and the possible loss of your tree.
Cut out any diseased and dead wood and take a little bit extra to ensure you have it all.
Ensure you clean your cutting implements before and after, and if possible, burn the affected wood safely so it cannot further contaminate the tree or other surrounding trees.
How Do You Prune A Grapefruit Tree In A Container?
The basic principles of pruning a container-grown tree are the same as those planted in the ground.
Typically they will be much smaller, and it can be necessary to prune them to maintain their small size. This is done by removing new shoots that are growing larger than your desired length in the dormant period and thinning out extra growth on scaffold branches to stimulate more fruit production.
Again try not to interfere with the canopy shape of the tree once mature and allow it to have sufficient leaf coverage to keep the trunk and branches out of the sun.
How Tall Do Grapefruit Trees Grow?
The height of a grapefruit tree will depend on several things:
- The variety
- If it is grafted onto dwarf or semi-dwarf rootstock
- Climate
- Soil type
- Water accessibility
- Nutrient availability
- Health
There is a wide variety of different grapefruit trees available, and they each have a height range they will typically grow to.
Standard grapefruit trees will generally grow to between fifteen and thirty feet over their lifetime.
How Do You Rejuvenate a Grapefruit Tree?
One of the biggest problems faced by citrus trees of all kinds is overwatering or insufficient sunlight.
- Soil – Root rot is a common issue and comes from the roots being wet for long periods. Citrus trees do need quite a lot of moisture and like a slightly sandy, loam soil that drains readily but also holds some water and nutrients that can be made readily available as required.
- Space – If when you planted your tree you didn’t select a place with direct sunlight, then it’s very likely that your grapefruit tree won’t be happy. If possible, prune back surrounding trees to open up the space and allow more sunlight in.
- Transplantation – This is only possible with very young trees less than two years old, as after that the root system will be too established, and trying to move the tree is likely to cause shock, which may kill the tree. If transplantation or cutting back other trees isn’t possible, it may be necessary to plant a new tree in a better location.
- Disease – This is another problem that can be a lot harder to deal with, as depending upon which disease the tree has, there may not always be a cure.
- Herbicide – Citrus trees don’t do well if they have a lot of competition from grasses or weeds around their base. Unfortunately, many people use herbicides to get rid of these, but citrus is particularly susceptible to chemicals, and the roots will take them up and slowly kill the tree.
- Weed Suppression – A better method of controlling grass and weed growth around the root zone of your grapefruit tree is to lay a membrane that suppresses weed growth while still allowing water and air to pass through.
- Mulch – This can also be very beneficial, but too thick a layer can again cause excess moisture buildup, particularly in dormant months. During the winter, pull the mulch away from the trunk and leave a gap of around 8 to 12 inches, depending on the size of your tree. The larger the tree, the bigger the gap.
- Nitrogen – The deficiency of this element is another problem that can make your tree sick. Use an organic, slow-release fertilizer, preferably one for citrus trees, to prevent this.
A nitrogen deficiency can be identified when leaves growing on new wood are healthy and green but leaves growing on older wood turn yellow and drop off.
Never allow any fertilizer to come into contact with the trunk of the tree, as it can burn it.
Conclusion
It is only in the first few years of a grapefruit tree’s life that you will have to do any serious pruning in order to give it a strong, healthy shape for the future.
After this, it is just annual maintenance which generally involves a very light amount of cutting simply to get rid of any unrequired wood and to maintain a pleasing overall shape.
Excessive pruning of citrus trees can be very detrimental, particularly if their branches and trunk are overly exposed to sunlight, as this will burn them.
They require a thick canopy of leaves, and this extends right down to around a foot from the ground, although you don’t want the branches to actually touch the floor.
Remember that most citrus trees fruit most heavily on their lower branches, so removing these will reduce the amount of fruit the tree produces.
Want to learn more about growing and caring for grapefruit trees? Head on over to our other articles, or find more great information resources about a wide range of farm and animal topics on our site.
