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Washington State University
Gardening in Western Washington -
Native Plants
(Identifying, Propagating & Landscape)
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| Propagation from
cuttings involves removing certain parts of living plants and
putting them in a growing medium so they form roots. Cuttings are
a good way to obtain new plants, and often produce useable plants
more quickly than seeds.
Hardwood cuttings are
taken when the plant is not actively growing– usually late fall
through winter and can be taken from both deciduous
and evergreen plants.
Because hardwood cuttings from deciduous plants are collected
after their leaves have fallen off, the cuttings can focus on
developing roots and require less care than other types of
cuttings.
- Cuttings from deciduous plants
can be taken as soon as the plant has dropped its leaves. Wait
until early winter to take cuttings from needle or broadleaf
evergreens.
- To avoid spreading disease,
clean your pruning shears with rubbing alcohol or a 10% bleach
solution (1 part bleach to 9 parts water) before using them in
a new area. Protect the donor plant by using only sharp tools,
making all cuts just above a leaf node. Avoid
leaving stubs that will die back), and taking no more than 1/20
(5%) of any branch for cuttings.
- Select young, straight shoots
growing up from the center of the plant or from near the
ground, as these usually root better than those taken from
other regions. Take shoots that are at least the diameter of a
pencil (except snowberry, which can be thinner). Collect long
branches– you will be dividing them into individual cuttings
later.
- Put the cuttings in a plastic
bag, and keep them cool, moist, and out of direct sunlight.
- To prepare individual
cuttings:
a) Clean your shears with
rubbing alcohol or a 10% bleach solution to avoid spreading
disease.
b) Cut the branches into pieces
long enough to have at least two leaf nodes-- preferably three
or four (about six inches long for most species). The end of
the cutting closest to the roots (the "bottom") should be cut
at a 45° angle, just below a node. In order to avoid confusing
the bottom with the top of the cutting (which is critical),
cut the top at a right angle (straight across).
c) Continue making cuttings out
of the branch until it becomes too short or too thin, then
discard the remainder into your compost pile.
d) For cuttings from needle or
broadleaf evergreens, strip off all needles or leaves on the
lower half of each cutting (the end near the slant cut).
e) If you are not planning to
plant the cuttings immediately, store them in bundles, covered
with damp sawdust or bark, in a cool place. Be sure to label
them!
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Before planting, treat the
bottom inch of the cutting with rooting hormone. (Follow the
directions on the hormone container; usually you have to wet
the cutting, then dip the slanted end in rooting hormone.)
This will stimulate the cutting to produce roots. Always
wear rubber gloves when using rooting hormone. A few
species, such as willows, do not require rooting hormone,
but the success rate for most species will improve
dramatically with it, and many species will not root without
it.
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Cuttings can be planted in pots (1 gal. containers work
well) or into outdoor beds. Garden soil will work fine, but
you may want to add vermiculite, perlite, or well-composted
sawdust to help retain water and avoid soil compaction.
Plant the cuttings with the top (straight-cut) ends up, deep
enough that only one or two nodes protrude above the soil.
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Cuttings can stay outside over the winter, but they should
be protected from freezing, wind, and full sunlight.
Cuttings from needle and broadleaf evergreens need to be
kept under plastic and misted at least once a day to keep
them from losing too much moisture through their leaves.
Cuttings from deciduous plants can be left exposed to the
rain, but need to be in containers that drain well; if kept
inside, they need to be kept in a spot that is cool and
humid. By the end of their first growing season, most
cuttings should be well-established and ready to plant.
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Native plants
that propagate well from hardwood cuttings:
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Credit:
Leigh, Michael. Grow Your Own Native Landscape.
Revised Edition, June 1999. |
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