This week we're at Gwinnett Technical
College. We'll learn about plant
propagation, how to start plants from seed, from cuttings
division. These are great ways to start plants for your
own garden or to pass them along to friends.
Starting plants from seed or cuttings
is fun and actually easy, not
difficult as many believe. First identify the nature of
the plants you
wish to propagate or multiply. Marigolds are annuals. Annuals
short life, they are femoral. Femoral means they germinate,
and set seed in a few months. The best way to propagate
this plant is
by seed, that's mother natures way of propagating this plant.
consider plant hardiness, the plants ability to withstand
cold temperatures. A hardy plant will tolerate temperatures
below 32 degrees. Dusty Miller and some Petunia varieties
are hardy plants. A half hardy plant or half hardy annual
will tolerate those temperatures but needs some protection.
A tender annual will not accept temperatures that low, Marigolds
and Begonias are examples.
In propagating plants start with cleanliness.
Use a solution of 1 part
bleach and 10 parts water. When working with flats used
before - use
this solution. Spray them or dip them in the solution. Afterwards
them off to keep the chemical away from the plant. This
protect the plant from fungus and bacteria.
When buying seeds from a garden center
check to see when the seeds
were collected. On every packet there is needed information,
typically on the back. It will tell you the year of the
seeds. If new, you don't need to worry about them losing
viability. There is nothing wrong with using older seeds
or seeds collected from your garden, they may just not be
as uniform, probably resulting in a greater variation in
height. A good way to save seeds is with a zip lock bag.
Label them with a permanent marker and place them in a cool,
dry, dark place - a
refrigerator or a freezer is ideal. Germination of seeds
easy. First select a container, a germination flat is best.
typically 11 inches by 22 inches and 2-3 inches deep. They
holes in the bottom that will allow excess water, excess
drain through. We don't want to create a swamp and it has
height to hold a good amount of soil. The soil mix should
be very small
particles or fine texture because that holds moisture well.
soil mix has a lot of peat that, again, holds moisture.
actually volcanic rock and is important because it holds
amounts of peat and volcanic rock are a good mix, both are
sterile, minimizing bacterial problems. Pour the mix into
germinating flat, until about half full. If filled to the
top it would
waste soil. Don't pack it, a good soil mix is already the
density. The soil should be as level as possible. Then completely
and evenly saturate the soil with water, by doing this you
shouldn't need to
water again before the seeds germinate and start to grow.
By watering before seeds are placed you won't need to worry
about displacing seeds and washing them away. You can tell
the soil is completely saturated if
you notice water dripping from the bottom of the container.
When placing the seeds there are several things to consider.
Size is a consideration. If the seeds are very small, Begonias
for example, have 2 million seeds per ounce, place those
type seeds on the top of the soil surface almost like dust.
Morning Glory seeds are large, so place them at a depth
about 2 times their diameter. An easy way to do this is
to take something like a plastic fork and make a little
row in the soil, place them about 2 times their diameter
deep and about 2 times their diameter apart from each seed.
Once in the soil, temperature becomes a critical ingredient.
Most bedding plants like to germinate at around 65 - 75
degrees. Lower temperatures will mean the germination process
will take longer. A good place is on top of a refrigerator,
it is probably a little warmer than the rest of the house.
The key is to get the soil warm, more so than the air. Another
concern is holding water, we don't want to re-water every
day. One solution is to place a dome over the tray. A plastic
cover from a garden center works well, it creates a bit
of a terrarium like effect. Plastic wrap also works. Light
is also an important ingredient. Some seeds need light to
germinate, some need darkness. This varies by species, look
up the individual plant to make the determination. If you
want to limit the amount of light, and the temperature cover
the plastic top with a newspaper. Remember 65-75 degrees
is the ideal temperature. Once the seeds start to sprout
they need sunlight. When left in the darkness too long they
will become spindly or lanky. The seedling has just a small
amount of energy stored, it will suffer if it has to look
for light at an early stage. Therefore as soon as the seedlings
sprout, which may be a week or two, get them to bright,
indirect light. The best time to transplant the seedlings
has to do with "true leaves," these are the third
or fourth leaves that emerge. The first two are called cotyledons
and they are not true leaves. When the third and fourth
leaves emerge it's time to move the plant into it's final
container or at least into a larger container where it can
grow out. Select a container that will provide plenty of
root space. Again, use a premium potting mix, one with good
aeration, one that holds moisture well, however for this
application one that is coarser than the germinating mix.
Make sure the soil is completely saturated with water. Dr.
Rick uses an 18-0-1. There are 18 individual pots in one
flat, this works well if you're going to keep the plants
in the container for a month or two. Saturate the soil with
water. Place only one plant per cell, even if they are small.
When moving try to touch only the leaves, avoid touching
the stem or roots. Make a small hole in the potting mix
and push the root system into the hole and potting mix.
Tuck it in, making sure the seedling is about the same depth,
possibly slightly deeper than before. Once the entire flat
is planted, it needs to be hardened off. These plants were
grown in greenhouse like conditions so they need to become
acclimated to outside temperatures and conditions. An easy
way to do this is for a week or so put the plants outside
for an hour or so each day. Make sure the temperatures aren't
particularly hot or cold. Once acclimated they can stay
outside as long as temperatures don't drop below 32 degrees.
Pests can be a problem for our plants.
Many pests are so small that we
can't see them. The Spider Mite is an example. although
very small it
causes a lot of problems. One method of determining whether
Spider Mites is to place a piece of paper underneath a leaf,
the leaf. The tiny mites will fall onto the paper and look
specks of pepper, but they move. If present, a Mitacide
recommended. Mites are not insects, they can reproduce or
complete their life cycle in as little as 3 to 7 days, they
are extremely prolific. When Mites are severe you will see
webs and thousands of Mites on your plants. Their mouth
is like sandpaper, they tear into the leaf. This causes
speckling or stippling on the top of the leaf. This causes
not only aesthetic damage but they can kill the plant. They
thrive in hot, dry conditions. Water is one way to control
them, plenty of water on the
leaves controls them.
Another way to start plants is through
vegetative cuttings. A herbaceous plant is tender, succulent.
The stems are full of water, there is no woody part to them.
Take a cutting early in the day, when a lot of
water is in the stem. They tend to root better at this time.
should be 2-3 inches long. Use a sharp knife or scissors
they'll do less damage to the tissue. Remove the leaves
from the stem that will go beneath the soil. You can actually
remove a portion of the leaf, it will still be able to photosynthesize
but not take too much room. The cuttings should not touch
each other. Use a standard 6 inch pot - 6
inches across and 6 inches deep, fill it with a premium
one with pearlite and peat. Fill the container almost to
the top with this
mix, don't compress or push down on the soil because that
Place the cutting gently in the mix. Make your cut below
where the leaves emerge. This tends to restrict fungus and
bacteria from getting into the vascular system. Coleus is
a good plant to start from cuttings. Place them around the
outside of the container, leaning over the side of the container,
this provides more space in the center of
the container for more cuttings. Try to keep the leaves
reducing the chance for disease. Once in place, use a fog
saturate the soil, trying to keep water from the leaves
- again to
reduce the chance for fungus and bacteria. With the container
place a plastic bag and cover the entire pot. If needed
put a piece of
bamboo in the container to hold the bag up. This creates
like conditions with high humidity, keeping the cuttings
(too much water from leaving the leaf surface). This creates
situation where there is almost 100% humidity, they'll root
easily and we'll be able to gingerly take them out and have
Division is another way to start a new
plant. This entails taking an
entire part of a plant, removing it and starting a new one.
This is an
asexual approach, which unlike seed production requires
parents to produce seed. In this case we're taking a clone
of the parent plant. Irises work well with this approach.
The best time
to propagate Irises is right after they bloom. You'll need
a sharp knife,
possibly a saw. Remove the above ground and below ground
parts of the plant. What remains is the rhizome, the underground
stem. This is
where the plant stores its food and energy. It is a large
white part of the plant just below the soil surface. Do
make sure it has healthy white
roots. Cut this into 1-8 different fans depending on the
size of the
rhizome. Look for young, plump material, then make your
sure it fits into the container you've planned. Don't place
it too deep
because the crown could be damaged if planted too deeply.
premium potting soil and make sure the soil is moist. This
shocks or stresses the plant, it will take a week or so
for the plant to recover. Dr.
Rick likes to start them in pots so he can offer greater
Another way to start plants involves taking
a leaf cutting from, for
example, a Dragon Wing Begonia. Remove just one leaf from
this allows a large number of cuttings. A large leaf with
is needed. Cut through the vein in about two different places.
Set it on
the soil so that the leaf touches the soil surface. Use
like a paper clip, open it up fully, then using the clip
press the leaf to
the soil, making sure good contact has been made between
the soil and the leaf. You might want to add some soil to
the top of the leaf. Keep
this moist, Dr. Rick uses a dome over the soil and leaf
to keep it moist.
After several weeks roots will form and you will have the
of a new Begonia.
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