Grapefruit trees (Citrus x paradisi) must have strong, healthy branches to support the large fruits the plant produces. Citrus trees don't require extensive pruning, but regularly pruning grapefruit trees helps to remove dead and damaged branches and avoids overcrowding of branches to ensure you get the best possible yield of fruit each year. Grapefruit grows in U.S. Department of Agriculture plant hardiness zones 9 through 11.
Pruning a Nursery Sapling
Choose a 2- to 4-foot tall nursery sapling when establishing a grapefruit tree. Prune the top from 18 to 24 inches above the ground. Prune all but three or four evenly spaced branches growing upward at a 45-degree angle or greater. These will become the main, grapefruit-bearing scaffold branches growing out from the trunk. Prune off all branches below the scaffold branches.
Selecting good scaffold branches will reduce your pruning chores in future years.
When to Prune
Prune grapefruit trees from their second year on in late winter through early spring after the risk of freeze has passed to give the tree time to grow leaves necessary to protect exposed limbs from the hot summer sun, advises the University of California. Pruning too early can stimulate a growth flush that can be damaged by a late spring frost. Do not prune large sprouts or limbs in summer unless they have been damaged.
Do not immediately prune limbs damaged by a winter freeze. Wait until early summer to cut back dead branches to healthy, green wood.
When pruning grapefruit trees exposes a cut to direct sun, prevent sunburn by covering the cut with a mixture of 1 part white latex paint and 1 part water, advises the University of California Extension.
What to Prune
Sprouts, also called shoots, suckers or water sprouts, may grow from your grapefruit tree. They emerge from several parts of the tree:
- Below the bud union. This part of the trunk is usually near the soil and you'll see the trunk isn't quite straight or there's a bulge. This is the spot where
the grapefruit cultivar, the scion, was grafted onto a rootstock. The bark on
the rootstock will usually also have a different texture than the scion.
- From the trunk.
- From large branches.
Sprouts growing from rootstocks will likely be thorny and yield inedible fruit. Prune rootstock sprouts that grow from soil surrounding the tree or from below the graft union. Prune sprouts that grow almost straight up from large limbs. These sprouts often grow above the top of the canopy. They bend from the weight of grapefruits growing at their tips and are more likely to break in the wind.
Prune both small and large branches if they crisscross, rub against grapefruits, or are damaged or dead. Remove limbs growing from the bottom of the main branches as these often break, ripping off bark as they do. Remove lower branches that grow in the shade of branches above them since they won't yield grapefruits without sun. Do not prune the top branches or all of the interior branches. The main scaffold branches need them for robust growth.
You can prune low-hanging branches to make the tree look better, but there is nothing wrong with letting the canopy extend to the ground. The best grapefruits will grow on low-hanging branches.
How to Prune Sprouts
You can snap off small sprouts with your hand. Use hand pruners to cut the sprouts flush with the tree. If you do that, do not leave a stub. Leave the collar, that swollen area at the base of a sprout or limb. There is no need to add a protective layer of white latex paint to cuts made to remove sprouts.
At least once a month, prune sprouts from the trunk of a small tree. Remove all sprouts from the bottom 10 to 12 inches of the trunk.
To prevent the spread of plant diseases when pruning citrus, make sure your pruning tools are sharp and sterile. You can disinfect the tools by wiping the blades with rubbing alcohol, advises the University of Florida IFAS Extension.
Pruning Grapefruit Trees
Prune sprouts growing up or down from scaffolding branches one at a time, beginning with the bottom branch.
Prune branches flush with the collar, not the trunk. This will help the wound heal and reduce the chances of sprouts growing where you made the cut.
Follow a different procedure to prune a branch more than 1 1/2 inch wide.
Things You'll Need
White latex paint
Step 1: Sterilize Pruning Tools
Wipe down all of your pruning tools with rubbing alcohol to disinfect them.
Step 2: Saw the Branch
Saw the bottom of the branch one-third through from the bottom at a point 6 to 12 inches from the collar where it joins the trunk.
Step 3: Complete the Cut
Saw downward from the top about 3 inches out from the bottom cut. The branch will drop.
Step 4: Remove the Stub
Saw the remaining stub off at the collar.
Step 5: Cover the Exposed Cut
If the cut is exposed to the sun, paint it with a 50:50 mixture of white latex paint and water.