Basic Techniques for Propagating Plants
PP068 (3/01R)
By Dr. Sharon M. Douglas
Department of Plant Pathology and Ecology
The Connecticut Agricultural Experiment Station
123 Huntington Street
P. O. Box 1106
New Haven, CT 06504-1106
Telephone: (203) 974-8601 Fax: (203) 974-8502
Email: Sharon.Douglas@po.state.ct.us
There are many reasons for propagating plants. One basic
reason is simply to make multiple plants from a single plant.
Another reason is to make a young attractive plant from an old,
leggy plant. Other reasons are to propagate a particular plant
because of its unique or attractive features and to propagate
plants for sentimental reasons. Regardless of the reason for
propagating plants, there are some basic factors that are useful
to ensure success:
1. Use only healthy, vigorous source plants.
2. Use the most appropriate method, growth stage, and timing for
the plant.
3. Protect propagation material from heat and from drying; use
the material as quickly as possible after it is prepared.
4. Give newly propagated plants extra attention and care during
their establishment phase.
Techniques:
This fact sheet focuses on techniques for vegetative
propagation of plants. Plants propagated using these methods have
the same characteristics as the parent or source plant since
vegetative material is used and no genetic recombination is
involved. The key techniques for propagation that will be
highlighted are: leaf cuttings, stem cuttings, simple layering,
and air layering.
Although many of the techniques can be used for a range of
different types of plants, it is important to know that some
plants root better at a particular stage of growth, at a specific
time of year, or using a particular technique. Numerous reference
books and experience will help to determine the best time and
method to propagate specific plants.
Basic Tools and Equipment:
As with any procedure, there are some basic tools and
equipment that are necessary in order to complete the job and the
following list highlights some necessary and optional items:
Pruning shears
Scalpel, sharp knife, or razor blade
Paint brush
Wooden matches1
Small wooden sticks
Wooden or plastic stakes1
Clear plastic bags and plastic wrap
Rooting hormone2
Tape1
Pots or flats of various sizes
Soil-less potting mix or a 1:1 mix of peat moss and clean, coarse
sand
Sphagnum moss1
Wire or wire coat hangers
Propagation mat (used for bottom heat)
1Used specifically for air layering and/or simple
layering.
2Rooting hormone is usually sold as indole butyric
acid (IBA) and is available in many formulations and
concentrations; for plants that are readily propagated by
vegetative methods, use of hormones promotes more root growth in
a shorter period of time; for plants that are not easily
propagated by these methods, rooting hormones will not help with
root development.
Leaf Cuttings:
A number of plants will readily produce new plants from leaf
cuttings. Although there is no dependable way to distinguish
these plants from others, most plants that root successfully from
leaf cuttings have thick, fleshy leaves which often grow in
rosettes. These include many of the common houseplants such as
gloxinia, African violet, begonia, and peperomia. (Refer to
Diagram 1.)
Procedure:
1. The best time to start leaf cuttings is when the plants are in
a strong growth phase, usually from early summer to early fall.
2. Select a pot or flat of the appropriate size for the number of
leaf cuttings that you will be rooting.
3. Prepare the rooting medium (either a soil-less potting mix or
peat moss and coarse sand); this should be moist but not wet;
fill the pots with the medium.
4. Select and cut healthy leaves with petioles from the source
plant using a sharp, clean knife.
5. Trim the base of the petiole but leave enough to insert into
the rooting medium without the leaf touching the surface.
6. Dip or lightly dust the cut surface with rooting hormone (this
is optional, depending on the plant); in order to avoid
contaminating the hormone, put a small quantity in a cup rather
than sticking the cutting into the original container.
7. Make a few planting holes in the rooting medium with a small,
clean stick.
8. Gently insert each leaf cutting into a hole so that the leaf
is just above the rooting medium; carefully firm the medium
around each cutting with your fingers but avoid injury to the
petioles.
9. Place a wire frame over the pot or flat; put the container
into a clear plastic bag making certain that the frame is
supporting the plastic bag so the plant material is not touching
the bag; this creates a "mini-moist chamber" to keep
moisture around the leaves as they root.
10. Place the chamber in a warm location out of direct
sunlight! A propagation mat as a source of bottom-heat is helpful
but not necessary.
11. Occasionally inspect the pot for condensation and add water
as necessary to keep the potting medium moist but not wet.
12. After 3-5 weeks (depending upon the plant being propagated),
roots should have started to form.
13. When plants have developed a sufficient root system,
gradually "harden-off" the new plants by opening the
bag and increasing light levels.
14. Place the newly rooted plants into individual pots using care
to avoid injury to the new roots.
Stem Cuttings:
This technique is probably the most versatile of all methods
used for vegetative propagation. It can be used for both
herbaceous and woody material. Herbaceous stem cuttings can be
made from houseplants, annual flowers and bedding plants, ground
covers, and some perennials. Stem cuttings from woody ornamentals
can be taken at different stages of development and are
categorized as softwood, semi-hardwood, and hardwood cuttings.
Softwood stem cuttings are taken in late spring or early summer
and consist of tender shoots of current season growth.
Semi-hardwood stem cuttings are taken from mid- to late-summer
and consist of current season growth that is firm and has begun
to form woody tissues. Hardwood stem cuttings are taken in late
fall or winter and consist of woody stems that have just
completed their first season of growth. For deciduous plants,
these are taken after the plants have dropped their leaves.
(Refer to Diagram 2.)
Herbaceous and Softwood Stem Cuttings:
These types of cuttings are appropriate for many popular
houseplants such as philodendron, Christmas and Thanksgiving
cactus, jade, and coleus, many annual or bedding plants such as
impatiens and geranium, popular ground covers such as pachysandra
and English ivy, and woody ornamentals such as magnolia and
maple.
Procedure:
1. These cuttings can be taken at the time appropriate for the
particular plant to be propagated (e.g., for houseplants or
bedding plants this is when new shoots appear in spring; for
woody plants it is when the new shoots have expanded and are
still tender in late spring or summer).
2. Select a pot or flat of the appropriate size for the number of
cuttings that you will be rooting.
3. Prepare the rooting medium (either a soil-less potting mix or
peat moss and coarse sand); this should be moist but not wet;
fill the pots with the medium.
4. Select and cut terminal shoots (preferably not in flower) from
the source plant using a sharp, clean knife or pruning shear; the
length of the cutting is determined by the source plant (cuttings
usually vary from 2-8 inches in length).
5. Remove the leaves near the cut end making certain that some
leaves (3-8) remain on the cutting; if the cutting is in flower,
carefully pinch off the flowers and flower buds.
6. Use a clean razor blade or scalpel to remove a thin slice of
tissue about ½ - 1 inch long on two opposite sides of the cut
end or base of the cutting; this provides a surface for root
development.
7. Lightly dust the cut sides of the cutting with rooting
hormone, as necessary; in order to avoid contaminating the
hormone, put a small quantity in a cup rather than sticking the
cutting into the original container.
8. Stick the cuttings into the pots or flats of prepared rooting
medium about one-third to one-half of the total length of the
cutting; carefully firm the medium around each cutting with your
fingers but avoid injury to the stem.
9. Place a wire frame over the pot or flat; put the container
into a clear plastic bag making certain that the plastic bag is
supported by the frame so the plant material is not touching the
bag; this creates a "mini-moist chamber" to keep
moisture around the leaves as the cuttings root.
10. Place the chamber in a warm location out of direct sunlight!
A propagation mat as a source of bottom heat is helpful but not
necessary.
11. Occasionally inspect the pot for condensation and add water
as necessary to keep the potting medium moist but not wet.
12. After 5-8 weeks (depending upon the plant being propagated),
roots should have started to form.
13. When the cuttings have developed a sufficient root system,
gradually "harden-off" the new plants by opening the
bag and exposing the cuttings to increasing light levels.
14. Place the newly rooted plants into individual pots using care
to avoid injury to the new roots.
15. New cuttings will require extra care during the establishment
phase.
Semi-hardwood Cuttings:
Follow the same techniques for herbaceous or softwood
cuttings but select cuttings at the appropriate stage of growth
(e.g., mid- to late-summer). These types of cuttings are
appropriate for woody ornamentals such as azalea, rhododendron,
butterfly bush, rose, and euonymus.
Hardwood Cuttings:
Follow the same techniques for herbaceous or softwood
cuttings but select cuttings at the appropriate stage of growth
(e.g., late fall or winter). These types of cuttings are
appropriate for woody plants such as blueberry, juniper,
arborvitae, holly, and yew.
Simple Layering:
This technique can be used for some houseplants as well as a
number of woody plants. Simple layering is particularly useful
for plants that are difficult to root from stem cuttings or
leaves. Unlike stem cuttings which are taken from the source
before rooting has occurred, this technique allows roots to
develop on a stem while it is still attached to the source or
"mother" plant. The basic assumption is that roots will
develop when a position on the stem is forced into close contact
with a rooting medium. (Refer to Diagram 3.)
Houseplants:
This technique works best on plants that have a naturally
trailing growth habit such as ivies and philodendrons.
Procedure:
1. The best time to start these is when the plants are in a
strong growth phase, usually from early summer to early fall.
2. Select a pot of the appropriate size for the stem that you
will be rooting.
3. Prepare the rooting medium (a soil-less potting mix is
preferred); this should be moist but not wet; fill the pots with
the medium.
4. Select a stem (or stems since more than one plant can be
layered from a mother plant at a time) long enough for layering;
remove any leaves from the area of the stem where roots will
develop; this is usually several inches from the growing tip of
the stem.
5. Carefully pin the section of the stem for rooting down into
the pot with rooting medium with a U-shaped piece of wire
(old-fashioned hair pins work well); sometimes a slight nick in
the stem with a razor blade or scalpel will help; (another option
is a light touch from a paint brush with rooting hormone).
6. Make certain that the stem is slightly buried in the mix.
7. Water as necessary.
8. New growth at the tip is usually an indication that rooting
has occurred.
9. Carefully cut the young plant free of the mother plant with a
clean, sharp knife.
10. Repot the plant as necessary; new cuttings will require extra
care as they become established.
Shrubs and Woody Plants:
This technique works best on plants that have a naturally
trailing growth habit such as rambling or climbing rose,
raspberry, wisteria, and clematis but can also be used for
low-growing shoots of upright shrubs such as lilac and butterfly
bush. Deciduous plants are best layered in fall or winter whereas
evergreens are best layered in fall or spring.
Procedure:
1. Select a healthy, flexible, vigorous shoot that has grown in
the current year.
2. Gradually and carefully bend it down until a point of the
shoot about 9-12 inches from the growing tip reaches the ground.
3. Dig a hole about 3-4 inches deep at the point where the shoot
touches the ground; partly refill the hole.
4. Strip the leaves (if present) from the part of the branch that
will be rooted.
5. Cut a shallow slit in the underside of the branch with a
clean, sharp knife, razor blade, or scalpel and gently give the
branch a slight twist; (optional: you can dust the cut surface
with a rooting hormone using a paint brush).
6. Place the prepared stem section into the hole and carefully
bend the tip of the shoot upward.
7. Secure the stem into the hole with a U-shaped wire around 6-8
inches long (this process is called "pegging"); bend
the tip of the shoot upright and support it with a sturdy stake.
8. Fill the hole with the remaining soil and cover the pegged
area of the stem.
9. Thoroughly water the area and water as necessary during the
rooting process.
10. Plants usually root within 12 months; you can check for
rooting by gently pulling the soil away from the plant.
11. Once roots are visible and well-developed, sever the new
plant from the parent plant using a clean, sharp knife or pruning
shear; leave the newly rooted plant in the site for a 2-3 week
period of adjustment.
12. Dig and gently lift out the rootball and replant.
13. Newly rooted plants will require extra care during the
establishment phase.
Air Layering:
This technique is used for plants that are difficult to root
and it is especially helpful for houseplants that have become
tall and "leggy" such as an aging rubber plant,
codiaeum, or dracaena. Air layering can also be used to propagate
woody plants with stiff, upright limbs that cant be
propagated by simple layering such as some types of holly. As the
name suggests, the objective is to stimulate root growth at some
point on a stem without lowering the stem to the surface of the
rooting medium or soil. Old houseplants are usually good
candidates for air layering whereas one-year-old stems of woody
ornamentals are best for air layering. Older stems can be used
but the rooting process is substantially slower. (Refer to
Diagram 4.)
Procedure:
1. Select the portion of the stem where you want the roots to
develop.
2. If leaves are present in that area, carefully remove them.
3. Use a clean, sharp knife or scalpel to make a 1 to 1-1/2 inch
upward-slanting cut, starting below a leaf node, if possible.
4. Carefully prop the cut surface open (a wooden match works
well) and dust the surface with a paint brush containing a
rooting hormone; remove the match so the cut will close.
5. Wrap a piece of clear plastic wrap or a piece cut from a clear
plastic bag around the stem under the cut section.
6. Secure the plastic around the stem with tape.
7. Pack the cut portion of the stem with moist, but not wet,
sphagnum moss; make certain to press the moss to the base of the
stem so no air pockets are left.
8. Twist, seal, and secure the top of the plastic wrap tightly
around the stem with tape.
9. If air layering a houseplant, place the plant in indirect
sunlight.
10. If air layering a woody plant outdoors, routinely check the
air layer packet for buildup of water and insert drain holes if
necessary.
11. For houseplants, new white roots should be visible through
the plastic within 8-10 weeks; for woody ornamentals, rooting
usually takes one full year.
12. Remove the plastic and cut the stem right below the newly
developed roots with a clean, sharp pruning shear or knife.
13. Put the new houseplant into a new pot or transplant the woody
shoot into a protected site for several months.
14. Newly rooted plants will require extra care during the
establishment phase.
References:
Hartmann, H.T., D.E. Kester, and F.T. Davies Jr. (1997) Plant
Propagation: Principles and Practices, 6th
Edition. Prentice-Hall, Inc., Englewood Cliffs, NJ. 784 pp.
Dirr, Michael A. (1998) Manual of Woody Landscape Plants, 5th
Edition. Stipes Publishing L.L.C., Champaign, IL. 1187 pp.
Diagrams:
Diagrams are available upon request from the author.
Summary
Many types of plants in and around the home can easily be propagated using fairly simple, inexpensive procedures. This fact sheet highlights a few of the basic and most widely applicable techniques for vegetative propagation of plants. Some of these techniques can be used for houseplants, annual flowers, and bedding plants, whereas other techniques are more effective for woody ornamental trees and shrubs, ground covers, and vines.