Herbaceous cuttings are made from non-woody,
herbaceous plants such as coleus,
chrysanthemums, and dahlia. A 3- to 5-inch piece
of stem is cut from the parent plant. The leaves
on the lower one-third to one-half of the stem
are removed. A high percentage of the cuttings
root, and they do so quickly.
Softwood cuttings are prepared from soft,
succulent, new growth of woody plants, just as
it begins to harden (mature). Shoots are
suitable for making softwood cuttings when they
can be snapped easily when bent and when they
still have a gradation of leaf size (oldest
leaves are mature while newest leaves are still
small). For most woody plants, this stage occurs
in May, June, or July. The soft shoots are quite
tender, and extra care must be taken to keep
them from drying out. The extra effort pays off,
because they root quickly.
Semi-hardwood cuttings are usually prepared
from partially mature wood of the current
seasonís growth, just after a flush of growth.
This type of cutting normally is made from
mid-July to early fall. The wood is reasonably
firm and the leaves of mature size. Many
broadleaf evergreen shrubs and some conifers are
propagated by this method.
Hardwood cuttings are taken from dormant,
mature stems in late fall, winter, or early
spring. Plants generally are fully dormant with
no obvious signs of active growth. The wood is
firm and does not bend easily. Hardwood cuttings
are used most often for deciduous shrubs but can
be used for many evergreens. Examples of plants
propagated at the hardwood stage include
forsythia, privet, fig, grape, and spirea.
The three types of hardwood cuttings are
straight, mallet, and heel (Figure 3). A
straight cutting is the most commonly used stem
cutting. Mallet and heel cuttings are used for
plants that might otherwise be more difficult to
root. For the heel cutting, a small section of
older wood is included at the base of the
cutting. For the mallet cutting, an entire
section of older stem wood is included.
Procedures for Rooting Stem Cuttings
Cuttings should generally consist of the
current or past seasonís growth. Avoid material
with flower buds if possible. Remove any flowers
and flower buds when preparing cuttings so the
cuttingís energy can be used in producing new
roots rather than flowers. Take cuttings from
healthy, disease-free plants, preferably from
the upper part of the plant.
The fertility status of the stock (parent)
plant can influence rooting. Avoid taking
cuttings from plants that show symptoms of
mineral nutrient deficiency. Conversely, plants
that have been fertilized heavily, particularly
with nitrogen, may not root well. The stock
plant should not be under moisture stress. In
general, cuttings taken from young plants root
in higher percentages than cuttings taken from
older, more mature plants. Cuttings from lateral
shoots often root better than cuttings from
Early morning is the best time to take
cuttings, because the plant is fully turgid. It
is important to keep the cuttings cool and moist
until they are stuck. An ice chest or dark
plastic bag with wet paper towels may be used to
store cuttings. If there will be a delay in
sticking cuttings, store them in a plastic bag
in a refrigerator.
While terminal parts of the stem are best, a
long shoot can be divided into several cuttings.
Cuttings are generally 4 to 6 inches long. Use a
sharp, thin-bladed pocket knife or sharp pruning
shears. If necessary, dip the cutting tool in
rubbing alcohol or a mixture of 1 part bleach to
9 parts water to prevent transmitting diseases
from infected plant parts to healthy ones.
Remove the leaves from the lower one-third to
one-half of the cutting (Figure 4). On
large-leafed plants, the remaining leaves may be
cut in half to reduce water loss and conserve
space. Species difficult to root should be
Treating cuttings with root-promoting
compounds can be a valuable tool in stimulating
rooting of some plants that might otherwise be
difficult to root. Prevent possible
contamination of the entire supply of rooting
hormone by putting some in a separate container
before treating cuttings. Any material that
remains after treatment should be discarded and
not returned to the original container. Be sure
to tap the cuttings to remove excess hormone
when using a powder formulation.
The rooting medium should be sterile, low in
fertility, and well-drained to provide
sufficient aeration. It should also retain
enough moisture so that watering does not have
to be done too frequently. Materials commonly
used are coarse sand, a mixture of one part peat
and one part perlite (by volume), or one part
peat and one part sand (by volume). Vermiculite
by itself is not recommended, because it
compacts and tends to hold too much moisture.
Media should be watered while being used.
Insert the cuttings one-third to one-half
their length into the medium. Maintain the
vertical orientation of the stem (do not insert
the cuttings upside down). Make sure the buds
are pointed up. Space cuttings just far enough
apart to allow all leaves to receive sunlight.
Water again after inserting the cuttings if the
containers or frames are 3 or more inches in
depth. Cover the cuttings with plastic and place
in indirect light. Avoid direct sun. Keep the
medium moist until the cuttings have rooted.
Rooting will be improved if the cuttings are
misted on a regular basis.
Rooting time varies with the type of cutting,
the species being rooted, and environmental
conditions. Conifers require more time than
broadleaf plants. Late fall or early winter is a
good time to root conifers. Once rooted, they
may be left in the rooting structure until
Newly rooted cuttings should not be
transplanted directly into the landscape.
Instead, transplant them into containers or into
a bed. Growing them to a larger size before
transplanting to a permanent location will
increase the chances for survival.