|
Propagation of House Plants
June
23/2006
Sooner or later, most of us who grow house plants become
interested in the propagation of those plants; in other
words, taking cuttings to produce more plants. It's only
natural. If you're the kind of person who enjoys nurturing
living, growing things, like plants, chances are you'll want
to take the next step - propagation -
so you can share your happy plants with friends or family
members, or simply to see whether or not you can actually do
it. Perhaps you've got a vigorous philodendron plant that
threatens to obliterate the light from a window, or a
healthy dracaena plant that's about to grow through the
ceiling. You can't bear the thought of cutting it back and
throwing away any part of a healthy living plant, one that
you've taken such good care of. So vegetative propagation of
the plant is your likely impulse
"Vegetative propagation?" you may ask. Vegetative, in this
case, simply means 'non-sexual'. Sexual propagation is
propagation by means of seeds. A flower is pollinated, a
seed is formed (perhaps inside a fruit), the seed germinates
and a new plant is born. It's nature's usual mechanism for
reproduction of the species. Vegetative, or asexual,
propagation is reproduction by any other means, such as by
layering or cuttings, used to create new individual and
self-sufficient plants. Vegetative propagation generates new
and relatively mature plants without waiting for seeds to
sprout and seedlings to grow. It's also useful for reducing
the size of overgrown specimens. For house plants, there are
several effective methods of propagation that may be used,
depending on the type and the physical form of the plant to
be propagated.
The easiest and probably the most common way of propagating
house plants is by cuttings. There are several types of
cuttings that work well, again depending on the type of
plant in question. Stem cuttings are good for plants that
grow on vines, such as philodendrons, pothos, hoyas, ivies,
and similar plants. Using a sharp knife or bypass-style
pruning shears, cut a section of the vine or stem that
includes at least 4 to 6 nodes (the nodes are the places on
the stem at which the leaves are attached). Cuttings may be
taken from the growing end of the stem or from anywhere
along it. Strip the leaves away from the bottom node or two.
In most cases, new roots will emerge from the nodes.
Stem cuttings may be rooted in either water or a sterilized
potting medium. Cuttings with fairly slender stems will root
easily in plain water. Use tap water that has been left to
sit out for 24 hours or more to allow chlorine and fluorine
gasses to dissipate. Place the fresh cuttings into a glass
or jar of the water, submerging the exposed nodes but not
allowing any foliage to be in the water. It can be helpful
to drop a clear plastic bag over the cuttings and the glass
to increase humidity while the stems are rooting. Don't seal
the bag, however, as air circulation must be present to
avoid rotting. The bag can be supported over the cuttings
with wood plant stakes or dowels, so air can circulate from
underneath. Place the cuttings in bright, indirect light
away from full sun while they are rooting. Change the water
as necessary to keep it clear and oxygenated, and add water
to replace any that has evaporated or been used by the
plants. In most cases, roots should start t! o appear within
3 to 4 weeks.
Roots formed in water may appear sooner than those formed in
soil, but they may not be as sturdy and may have a more
difficult time adjusting to being transplanted. Therefore,
many growers prefer to propagate cuttings by rooting them in
a sterile potting medium or soil mix. Sterilized growing
mixes can usually be purchased at a garden center.
Otherwise, a mixture of half sand and half peat moss is good
for rooting most cuttings. Sterilize it by putting it into a
300-degree oven for an hour. Then moisten it before using.
Stem cuttings should be dipped into a powder containing a
rooting hormone and a fungicide (available from a garden
center) before inserting into the growing medium. Insert the
stem deeply enough so that the exposed nodes are covered.
Keep the medium moist but never soggy. Maintain high
humidity, perhaps by using a plastic bag as above or by
frequent misting with water. Place the cuttings in bright,
indirect light. After 5 or 6 weeks, cuttings should be rea!
dy for transplanting.
After cuttings have rooted, they must be planted into a
regular soil mix. Remember that their propagation media have
had no nutritional value, so the new potting soil should be
one that contains some amount of organic matter to provide
nutrients. Once the cuttings are established in their new
pots, after a couple of months or so, begin fertilizing with
an ordinary house plant food at one-half the normal dilution
rate.
Larger plants with heavier stems, such as dieffenbachias,
Chinese evergreens, larger philodendrons, some dracaenas,
etc., may also be propagated by stem cuttings. In this case,
cut the stem with about 6 or 7 leaves from the top of the
plant. You can also cut similar sections of stem from
further down. As before, remove 2 or 3 leaves from the
bottom of the cutting, exposing the nodes. Cut the upper
half away from each remaining leaf blade so as to reduce
moisture loss during propagation. Dip the bottom end of the
cutting into rooting powder. Then set the cutting aside for
a week or so, in a bright but shaded spot, allowing the cut
end to callus (similar to forming a scab) to keep the
cutting from drying out too much and from rotting as it
takes root. Once the callus has formed, insert the stem
cuttings into a sterile potting medium as mentioned before
until they've rooted.
Another, perhaps simpler way of propagating vining plants is
by layering. In this process, a section of the long stem of
the plant is simply pinned to the soil, without separating
it from the original plant, until it grows roots. Using a
U-shaped or hairpin-like wire, pin one or more nodes of the
original vine to the surface of the potting soil, which is
kept constantly moist but not soggy. You can pin the vine
back into the original pot or onto the moist soil in a new,
nearby separate pot. Once the layered stems have taken root,
simply cut the stem behind the freshly rooted nodes and pot
the cuttings separately. If you have enough vines and
they're long enough, you may be able to pin several stems
together into a new pot and create a whole new plant all at
once.
Some house plants may be propagated by leaf cuttings. These
include African violets, begonias, peperomias, and most
succulent plants, such as aloe vera, jade plant, kalanchoe
and sansevieria. Using a sharp, clean knife, cut the leaf
including any stem (the leaf petiole) from the main plant.
Dip the cut end in rooting powder. For soft or slender stems
like begonias and peperomias, insert the petiole immediately
into the rooting medium, nearly up to the base of the leaf
without touching it. For thicker leaves, like African
violets, allow the cut end to callus for 2 or 3 days before
inserting. Succulent leaves, including jade plant, aloe, and
similar plants, should callus at least a week before
propagation; otherwise the cuttings will tend to rot. Do not
supply any extra humidity for succulents, again to avoid
rotting from too much moisture.
For very heavy or woody-stemmed plants, such as rubber
trees, dracaenas, and large dieffenbachias, a propagation
technique called 'air layering' is best. Air layering allows
a large cutting to take root before being separated from its
mother plant, ensuring against loss of the cutting before
it's rooted. Using a sharp knife, cut a narrow, V-shaped
notch halfway into the stem at the point where you want
roots to form. This should be immediately below a node from
which the leaf (or several leaves) has been removed. Brace
the notch open with a pebble, a short stick or a piece of
toothpick to prevent it from healing closed. Dust the cut
with rooting powder. Wrap the area in and around the notch,
all the way around the stem, with damp sphagnum moss.
Depending on the size of the plant, you should wind up with
a ball of sphagnum moss approximately the size of your
clenched fist. Wrap the damp moss with clear Saran or
similar plastic wrap. Secure the wrapping above and below
the ! wad of moss with twist-ties. The moss should stay damp
throughout the rooting process (from 4 to 8 weeks). If it
tends to dry out, gently add water from the top to re-dampen
the moss. When vigorous roots are visible through the
plastic wrap, cut the new plant below the roots, remove the
wrap and plant the cutting in its own pot. The original
plant will send out one or more new shoots from below the
point where the cutting was removed.
Air layering is an excellent propagation technique to use
when the original plant has become tall and leggy. The
layering can be done at two or three points along the stem,
and when all have rooted, they may be planted together,
along with the original if desired, to create a new and much
fuller plant. It's best to begin this process in the spring
when growth is more active.
We hope this column has answered some of your questions
regarding house plant propagation. Remember to consult your
local professional florist for more details about these and
other techniques, and how best to apply them with specific
kinds of plants. It's fun to grow more house plants from the
ones you already have! In the immortal words of this
well-known phrase, "Go forth and multiply!"
Belmar Flower Shop Inc.
Reprinted with permission from
FlowerShopNetwork.Com
|
