This document provides guidance on pruning citrus trees. It recommends making clean cuts above the branch collar to promote healing without damaging the tree. Large branches should be removed using a three-cut method to prevent tearing. Regular pruning of small branches is best to remove dead wood and open the canopy for sunlight. Canopies should be thinned every few years and skirts pruned above ground level. Prunings can be composted rather than burned to benefit the soil. The goal is to shape trees for production while protecting them from pests and disease.

1. Pruning Citrus
How and What
Cindy Fake
University of California Cooperative Extension,
Placer & Nevada Counties
January 2012

2. How to Prune…
• Carefully!
• Citrus bark is thin and
easily damaged so avoid
nicks
• Make pruning cuts with the
blade toward the tree
• Cut cleanly and avoid
damaging remaining
branch
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3. How to Prune…
• Do not cut branches flush
with trunk
• Preserve branch collar =
ridge in bark around base
of branch
• Branch collar contains cells
that make woundwood which
grows over a pruning cut
• Branch collar also makes compounds to
defend tree against decay
• Do not paint or tar wounds
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4. How to Prune…
• When cut too closely,
wound includes trunk wood
• Do not leave long stubs –+/-
1 cm above branch collar is
sufficient
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5. How to Prune…
• Citrus has brittle wood
• Use a three-cut system for
branches larger than 2.5 cm
• Prevents bark tearing or
damage to remaining branch
• 1st cut: 30 cm from branch union
• Cut 1/3 to ½ way through the branch from underneath
(undercut)
• 2nd : A few cm up, cut from above, removing the
branch. Make the final cut just above branch collar
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6. How to Prune…
• If previously shaded branches are
exposed to sun, protect them from
sunburn
• Sunburn causes bark cracking and
cankers, which may kill the tree
• Paint exposed branches with
whitewash or 1:1 mixture of
interior latex paint and water
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7. What to Prune?
• Best is to prune branches less than
5 cm in diameter
• Why? …because they are mostly
living tissue and can protect
themselves against decay better
than larger branches
• This means pruning regularly, not
leaving it until you need to take
out large branches
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8. Types of Pruning: Topping
• Top young trees at planting,
esp. if they are tall and
spindly
• Promotes side shoots which
develop into a lower, fuller
canopy
• The shorter the tree, the
easier and more cost
effective the harvest
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9. Types of Pruning: Shaping young trees
• Prune downward growing
shoots to allow upward
growing buds to become
dominant
• Cutting the shoot just above
an axillary bud pointing
upward will redirect growth
upward
• Helps shape the tree for
optimal future production
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10. Maintenance Pruning
• Remove discolored, damaged,
or dead wood from trees as
necessary through the year
• Remove crossing branches or
branches that shade out
lower branches
• Remove branches infected with
citrus blast (Pseudomonas
syringae) when weather warms in
the spring
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11. Suckering
• Remove shoots below the bud
union as soon as they appear
• They are growing from the
rootstock and will not be
productive
• For Trifoliate rootstocks,
(Poncirus trifoliata) the rootstock
thorns can be a hazard to workers
and may damage fruit
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12. Removing Watershoots
• Long, thick, very vigorous
branches = water sprouts or
gourmands
• Grow very rapidly, using large
amounts of nutrients and water
• Typically remain vegetative for
multiple years
• Produce poor quality, large, rough
fruit, with dry segments
• Do not contribute to production, so
should be removed at the base.
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13. Reducing Tree Height
• Without regular pruning, fruit
production is on top of the tree
• Increases harvest time and costs
• Cutting major branches back to the
base is too hard on tree
• Only ¼ to 1/3 of tree height should
be reduced at a time
• Leave a few branches with good
foliage to photosynthesize and draw
water through the plant
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14. Canopy thinning
• Sunlight develops flavors and sugars
in the fruit
• A dense canopy prevents
sunlight from reaching fruit
• Thin canopy every 2-3 years
• Should see dappled sunlight beneath
tree at midday
• Thin out center branches
before they get large => increase
fruiting wood in the center
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15. Canopy thinning
• To facilitate thinning,
divide trees into
quadrants based on
scaffold or primary
branches
• Assess what is best in
each quadrant
• Prune one section at a
time
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16. Canopy rejuvenation
• This tree has too much trunk
and a very thin canopy, which
means yields are low
• Canopy needs to be brought
down so fruit is accessible
• Large branches with few
leaves and low bearing
potential need to be removed
to stimulate new growth in
center
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17. Skirt Pruning
• Branches that hang to the ground
• “Skirts” impede weeding, and fertilizer or
compost application
• Allow ants to access trees
• With heavy fruit loads, branches bend and
fruit touches the ground
• Fruit may be contaminated by soil
borne pathogens
• May cause plant disease, e.g. Brown rot
• Also potential food safety risk
• Skirt trees 50-75 cm above ground
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18. Pruning for Pest Management
• Soft-bodied, sucking insect pests
such as scale and mealy bugs thrive
in dense canopies
• They like high humidity and little
air movement
• The canopy protects pests from
predators and parasitoids
• Thinning the canopy often reduces
pest populations to the point that
insecticide sprays are unnecessary.
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19. Pruning for Pest Management: Citrus Blast
• Pseudomonas syringae bacteria
cause disease
• Common where Satsumas grow
• Usually starts at the base of the
petiole on small shoot
• Can move into larger branches
• Can cause cankers which kill limbs
• Prune out damage each spring to
remove as much of the infection as
possible
• Cut 15 cm below visible infection
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20. What to do with Prunings?
• Significant amount of green
material
• Could be returned to soil to the
benefit of trees
• Difficult to leave prunings lie in
orchard…hazard
• Burning loses all good benefits
• If prunings are not from diseased trees,
– Compost with cow or other manures
– Use compost as mulch along tree rows, under trees
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21. How and what?
Thank you!
Cindy Fake
University of California Cooperative
Extension, Placer & Nevada Counties
January 2012
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