P U B L I C A T I O N 8 0 0 1
Budding and Grafting
Citrus and Avocados in
the Home Garden
PAM ELAM
University of California Cooperative Extension Farm Advisor, Fresno County
It is often tempting, after eating a particularly good orange or avocado, to plant the seed
and grow your own tree full of these delicious fruit. Trees grown from these seed,
however, may produce fruit that are not edible at all, or the trees may not bear fruit
for many years. The best way to produce good-quality fruit is to grow seedlings from
them and then attach, by budding or grafting, material from trees that are known to
be good producers. Budding and grafting can also be used to change or add varieties
to mature citrus or avocado trees, a process known as top working.
This publication is a brief introduction to budding and grafting for the home
gardener. For more information, consult the materials listed at the end of this pub-
lication or contact your local Cooperative Extension office.
E S TA B L I S H I N G S E E D L I N G S
The best time of year to start citrus or avocado seedlings is in early spring. To ger-
minate citrus or avocado seed, plant them in a shallow container such as a nursery
flat or a pan with drainage holes in well-drained commercial potting mix. Plant the
seed two to three times deeper than their length. For example, a citrus seed about 1⁄4
inch (6 mm) long should be planted about 1⁄2 to 3⁄4 inch (12 to 18 mm) deep. Keep
the seed in a warm place—between 70° and 80°F (21° to 27°C)—and keep the soil
moist. Covering the nursery flats with clear glass or plastic will help maintain the
proper humidity. Avocado seed can also be germinated by suspending them in water.
Place toothpicks horizontally into the seed near the top. Suspend the wide end of
the seed in a small container of water with the toothpicks resting on the edge of the
container. Place it in indirect light and refresh the water at least weekly.
After germination (usually 12 to 15 days), replant the seedlings into a larger
container of good-quality commercial potting mix. (If all danger of frost has passed,
the seedlings may be planted directly into the ground where you want the tree to
grow instead of replanted into containers.) Good choices for containers include a
cardboard milk carton cut horizontally in half or a one-gallon can. Punch drain
holes in the bottom of the container. The seedling will be ready for budding or graft-
ing when it has grown to 24 to 30 inches (60 to 75 cm) tall.
K E Y S T O B U D D I N G A N D G R A F T I N G
Budding and grafting are vegetative propagation techniques in which a single bud or
stem (scion) of a desired plant (cultivar) is attached to a rootstock plant. In budding,
a single bud with its accompanying bark (often referred to as budwood) is used as
the scion. In grafting, part of a stem or branch is used as the scion.
One of the most important keys to successful budding and grafting is properly
positioning the scion on the rootstock. In order for the scion and rootstock to grow
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together, the thin greenish plant layer (cambium) just under the bark of the scion
and rootstock must be aligned so that they touch each other. If they do not touch
each other, the bud or graft will fail. Within 10 to 15 days, a successful bud or graft
forms a hard whitish tissue (callus) where the two cambium layers grow together.
Always use sharp cutting or grafting instruments and make clean, even cuts.
Options include a budding knife, a sharp kitchen knife, or a single-sided razor blade.
Do not allow the cut surfaces of the scion or rootstock to dry out: immerse cut
scions in a pail of water, wrap them in plastic, or graft them immediately after cut-
ting. Also, remove any leaves from scions after cutting to help keep the scions from
losing water. Keep the scions in a cool place during the work.
W H E N T O B U D O R G R A F T
Budding and grafting are best done in the spring or fall when the bark is easily sep-
arated from the wood. It should be timed to be early enough so that warm weather
will help ensure a good bud union, yet late enough so that the bud will not begin to
grow and callus will not grow over the bud itself. Citrus budded or grafted in the fall
must be protected from frost. Avocados are best grafted in the spring when the bark
is easily separated from the wood.
B U D D I N G
Budding is the standard method used to propagate citrus. Aside from being the eas-
iest method, it allows a large number of plants to be propagated from a small amount
of scion wood and is suitable for trees, rootstocks, or branches from 1⁄4 to 1 inch (0.6
to 2.5 cm) in diameter.
Budwood should be taken only from high-producing, disease-free trees (see
sidebar). The best citrus budwood is located just below the most recent flush of new
growth; the best avocado budwood is located near the terminal end of shoots that
have fully matured, leathery leaves.
How to make a T-bud
T-budding (see fig. 1) is generally the best budding method for citrus and avocados.
To make a T-bud, make a T-shaped cut on the rootstock about 8 to 12 inches (20
to 30 cm) above the ground (fig. 1A). The vertical part of the T should be about 1
inch (2.5 cm) long and the horizontal part
about one-third of the distance around the
rootstock. Twist the knife gently to open
flaps of bark. Avoid cutting through any
buds on the bark of the rootstock.
On the scion (fig. 1B), cut a selected
bud beginning about 1⁄2 inch (1.2 cm)
below the bud and ending about 3⁄4 to 1
inch (1.9 to 2.5 cm) beyond the bud. Make
a horizontal cut about 3⁄4 inch (1.9 cm)
above the bud down through the bark and
into the wood. Gently remove the shield-
shaped piece for budding (fig. 1C).
Slip the budwood down into the
T-shaped cut under the two flaps of bark
until the horizontal cuts of the bud match
up with the horizontal cut of the T
BUDDING AND GRAFTING CITRUS AND AVOCADOS IN THE HOME GARDEN 2
Figure 1. T-budding. A. Rootstock with T-shaped
cut. B. Cutting bud from budwood. C. Buds ready
for insertion. D. Bud inserted into the cut. E. Graft
wrapped with budding rubber.
A E D
C
B
WARNING: It is against
California law to bring cit-
rus budwood into the San
Joaquin Valley from any area
outside the valley. This law
protects commercial citrus
groves from disease caused by
the Tristeza virus. Budwood or
scion wood should be collect-
ed only from citrus that has
been tested in the last year
and found to be free of
Tristeza virus. Consult your
local county Cooperative
Extension office for
more details.
(fig. 1D). After inserting the budwood into
the rootstock, wrap the bud and rootstock
with budding rubber (fig. 1E). Budding
rubber is available from agricultural supply
or hardware stores; if budding rubber is
unavailable, use wide rubber bands, green
tie tape, or stretchy tape. Leave the bud
exposed while wrapping. Do not coat the
area with grafting wax or sealant.
If the budding is done in the fall, the
buds should be healed in about 6 to 8
weeks; in the spring, healing should take
about 3 to 4 weeks. After the bud has
healed, unwrap it and cut off the remaining
shoots or stock about 12 to 14 inches (30
to 35 cm) above the bud union. This will
be the nurse branch, which helps protect the new bud union. After the budwood has
grown a few new leaves, completely remove the nurse branch to about 1⁄8 inch (3
mm) above the bud union (fig. 2).
G R A F T I N G
Whip grafting
The best grafting technique for small-diameter (1⁄4 to 1⁄2 inch [0.6 to 1.2 cm]) root-
stocks is whip grafting. Whip grafting should be done in the fall or spring. Although
whip grafts use more scion wood than budding does, they allow the grafted plant to
develop more rapidly.
To make a whip graft (fig. 3), select as a scion hard and mature green wood. First
make a long, sloping cut about 1 to 21⁄2 inches (2.5 to 6.2 cm) long on the rootstock
(fig. 3A). Make a matching cut on the
scion. Cut a “tongue” on both the scion
and rootstock by slicing downward into
into the wood (figs. 3B–3C). The
tongues should allow the scion and root-
stock to lock together. Fit the scion to
the rootstock (fig. 3D) and secure with
budding rubber (fig. 3E). Apply grafting
wax to seal the union. To prevent sun-
burn, new whip grafts should be protect-
ed from the sun until they heal. After the
scion has begun to grow, remove any
growth from the rootstock. If necessary,
support new shoots by staking.
Bark grafting
The best grafting technique for large-diameter trees or branches is bark grafting (fig.
4). To make a bark graft, first cut off the rootstock (the trunk or branch to be graft-
ed) just above a crotch where smaller branches sprout out. If possible, try to retain
one branch of the original plant as a nurse branch. The nurse branch will
provide the scion nutrition and support from wind (the nurse branch will eventual-
ly be removed).
BUDDING AND GRAFTING CITRUS AND AVOCADOS IN THE HOME GARDEN 3
Figure 2. After T-bud begins to grow, remove
nurse branch just above the bud.
Figure 3. Whip grafting.
A. Rootstock stem cut for
grafting. B. Tongue cut into
rootstock to hold scion in
place. C. Scion cut for graft-
ing, with tongue. D. Scion and
rootstock properly aligned.
E. Graft wrapped with
budding rubber.
A B C D E
Cut vertical slits 21⁄2 to 31⁄2 inches (6.2 to 8.7 cm) long through the bark of the
remaining freshly cut rootstock stubs down to the wood. These slits should be
spaced 3 to 5 inches (7.5 to 12.5 cm) apart. Cut the scions 5 to 6 inches (12.5 to 15
cm) long with 4 to 6 buds per scion (figs. 4A–4C). If scions are cut longer than this,
they may dry out before healing. When cutting the scions, make a sloping cut about
3 inches (7.5 cm) long at the base of the scion.
Using a grafting knife or other very sharp knife, lift the bark on one side of the
slit. Insert the scion into the slit with the long-cut surface of the scion facing the
wood of the rootstock and push it down into the slit (fig. 4D). Make sure that the
scion fits snugly into the slits in the bark and that the cambiums are properly
aligned.
Secure citrus scions by nailing them in place with thin flathead nails or tying
them with strong cord or tree tape. Secure avocado scions with plastic nursery tape.
Coat all cut surfaces thoroughly, including the tops of the scions, with grafting wax
or pruning paint. To protect the graft from sunburn, paint it with white interior
water-based paint, either undiluted or mixed 50/50 with water. Paint the entire area
around the graft union, including the
scions, waxed areas, and the exposed
trunk below the graft union. Inspect the
grafts frequently and rewax them if they
begin to crack or dry out.
Once the scions begin to grow well,
remove all but one scion per branch.
Early on, however, prune the scions that
will be removed to reduce their vigor but
do not prune the scion that will be kept.
The one scion you keep will eventually
become a main scaffold branch. Any
nurse branches should also be removed
after all the scions are growing well.
T O P W O R K I N G
Top working is the process of changing fruit varieties on a mature tree. Most citrus
and avocado are top worked by bark grafting (see above). Top working should be
done in the spring or fall.
BUDDING AND GRAFTING CITRUS AND AVOCADOS IN THE HOME GARDEN 4
Figure 4. Bark grafting.
A–C. Scions cut for bark
grafting. D. Scions in proper
position (note flathead nail).
A B C
D
F U R T H E R R E A D I N G
Garner, R. J., and S. A. Chaudri. 1976. The propagation of tropical fruit trees. East
Malling, Kent, England: Commonwealth Bureau of Horticulture and Plantation
Crops, Horticultural Review No. 4.
Hartmann, H. T., and J. A. Beutel. 1994. Propagation of temperate-zone fruit plants.
Oakland: University of California Division of Agriculture and Natural Resources
Publication 21103.
Hartmann, H. T., and D. E. Kester. 1975, Plant propagation: Principles and practices.
3rd ed. Engelwood Cliffs, N.J.: Prentice-Hall.
Reuther, Walter. 1973. The citrus industry. Vol. 3. Oakland: University of California
Division of Agriculture Sciences.
Whitsell, R. H., G. E. Martin, B. O. Bergh, A. V. Lypps, and W. H. Brokan. 1989.
Propagating avocados: Principles and techniques of nursery and field grafting.
Oakland: University of California Division of Agriculture and Natural Resources
Publication 21461.
Tasaki, Ernia. 1985. All about citrus and subtropical fruits. San Ramon, CA:
Ortho Books
The author would like to thank Raul Gonzalas, Lindcove Research & Extension Center, for assis-
tance with this publication.
An electronic version of this publication is available on the DANR Communication Services
website at http://danrcs.ucdavis.edu.
Publication 8001
©1997 by the Regents of the University of California,
Division of Agriculture and Natural Resources.
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BUDDING AND GRAFTING CITRUS AND AVOCADOS IN THE HOME GARDEN 5
http://commserv.ucdavis.edu/freepub/
Establishing seedlings
Keys to budding and grafting
When to bud and graft
Budding
How to make a T-bud
Grafting
Whip grafting
Bark grafting
Top working
Further reading
Text4: ISBN 978-1-60107-181-1
