The goal of pruning a grapefruit (Citrus x paradisi) tree is to avoid overcrowded branches and giving the best possible yield of grapefruits. Prune to give the bearing parts of a tree air and dappled sunlight, meaning it is filtered through leaves. Pruning a grapefruit tree follows the same basic principles as pruning other citrus trees. Grapefruit grow 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 hot summer sun. 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 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.
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 the 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 main branches. These often break, ripping off bark as they do.
- Remove lower branches that grow in
the shade of branches above them. They won’t yield grapefruits without sun.
- Do not prune the top branches.
- Do not prune all 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 one 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, make sure your pruning tools are sharp and sterile. Soak them for five minutes in a solution of 1 part household bleach to 3 parts water, rinse them, then allow them to air-dry.
How to Prune Branches
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
- Pruning saw
- Household bleach
- White latex paint
Soak the cutting blade of a pruning saw for five minutes in a solution of 1 part household bleach to 3 parts water, rinse it, then allow it to air-dry.
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.
Saw downward from the top about 3 inches out from the bottom cut. The branch will drop.
Saw the remaining stub off at the collar.
If the cut is exposed to the sun, paint it with a 50:50 mixture of white latex paint and water.