Plant Propagation
Essential Standard 4.00: Examine factors relating
to plant growth and development.
Objective 4.02
• Use sexual and asexual methods of propagation.
Propagation
• The multiplication of a kind or species.
• Reproduction of a species.
Sexual Propagation
• Propagation from seeds.
• Pollen is transferred from the anther to the stigma.
• Fertilization occurs and seeds are produced.
Germination Rates
• Percent of seeds that sprout
– 75 out of 100=75%
• Rate is affected by seed viability,
temperature and moisture.
• Rates vary depending on plant and quality
of seed.
Seeds
• Plant depth depends on the size of seeds
– larger seeds are planted deeper
– water small seeds from bottom by soaking
Embryo
Seed Coat
Endosperm
Seeds
• Plant seeds no more than 1 ½ times the diameter of the
seed
– Larger seeds are planted deeper
– Smaller seeds are planted shallow (Petunias)
• Water small seeds from bottom by soaking to prevent
burying them
Seedlings (small plants)
• The first sets of leaves are called cotyledons
– Monocots produce one seed leaf
– Dicots produce two seed leaves
• True leaves are the second set of leaves
• Transplant seedlings when the first true leaves appear
• Before planting in the outdoor environment, reduce
humidity and water and make the environment more like
the outside to “harden off” plants
Seeds to Seedlings
Advantages of Sexual Reproduction
• Fast way to get many plants
• Easy to do
• Economical
Disadvantages of Sexual Reproduction
• Some plants, especially hybrids, do not reproduce true to
parents
• Some plants are difficult to propagate from seeds
Plants Started by Seeds
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Marigold
Impatiens
Begonia
Coleus
Salvia
Shasta daisy
Pansy
Asexual Reproduction
• Uses growing plant parts other than seeds
• Types of asexual reproduction:
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cuttings
layering
division or separation
budding
grafting
tissue culture
Rooting from Cuttings
• Rooting media should be about 4 inches
deep
• Best time of day is early mornings because
plants have more moisture
• Types of cuttings:
– stem
– leaf
– root
Stem Cuttings
• 1. Start with sterile flats, soil, and tools
• 2. Must include a node. A node is a point along
a plant stem where leaves or other stems are
attached
• 3. Internode is the area between two nodes
• 4. Cutting is taking a 4-6 inch piece of the
plant and forcing roots to grow
• 5. Using hormones helps speed up rooting
Stem Cuttings
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6. Dipping the cutting in fungicides helps prevent rotting
7. Herbaceous plants are soft-tissue plants
8. Woody plants are plants that produce woody tissue
9. Rooting media should be about four inches deep
10. Examples of plants that can be started by cuttings
– Herbaceous: geranium, impatiens, begonia, coleus
– Woody: holly, abelia, rosemary
Stem Cuttings-Step 1
Gather all materials needed
Stem Cuttings-Step 2
Cut 3 to 4 inch shoot from
stem tip
Stem Cuttings-Step 3
Remove lower leaves from the
shoot
Stem Cuttings-Step 4
Dip cut surface in rooting
hormone
Stem Cuttings-Step 5
Thoroughly moisten rooting
medium
Stem Cuttings-Step 6
Stick one or more cuttings in
rooting media
Stem Cuttings-Step 7
Cover with plastic wrap or place on
a mist bench in a warm area away
from direct sunlight.
Stem Cuttings-Step 8
Once rooted, cuttings can be
separated carefully and
transplanted
Leaf cuttings
• Usually propagated from herbaceous plants
• Midrib vein must be cut in order to make roots form
• Examples of plants started by leaf cuttings:
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African violet
Philodendron
Snake plant
Jade plant
Root Cuttings
• Should be spaced three inches apart in rooting area
• A sand, vermiculite, or perlite mixture is a good medium for
root cuttings
• Examples of plants that can be started by root cuttings
– Hosta
– Daylily
Cuttings
• The best time of day to take a stem, leaf, or root cutting is
early morning because plants have more moisture
Layering
• Scarring a small area of stem to produce new plants
– air layering
– trench layering
– mound layering
Air Layering
• 1. Make an incision at the node of a branch
• 2. Dust with rooting hormone, place sphagnum moss in
plastic and wrap around the incision, forcing roots to grow
on the stem of the plant
• 3. Once roots form, remove below the new roots for a new
plant
• Examples: Decora rubber plant, weeping (Benjamin) fig
Air Layering
Trench Layering
• New plants form at each node along the stem while still
attached to plant
• 1. Cut a trench and lay a branch in the trench
• 2. Types of trench layering are simple, tip, serpentine
• Examples: grapes, clematis
Trench Layering
Mound layering
• Mounding the soil on a branch
• Used for asexual propagation of azalea
Trench Layering
Division
• Cutting apart plant structures for
reproduction
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rhizomes
tubers
runners
stolons
suckers
Division
• Used on plants that grow in clumps
• Examples: hostas, daylilies, irises
• Also used on some grasses
Separation
• Separating natural structures of a plant without making a
cut
• Examples: bulbs and corms
Grafting
• Joining separate plant parts together so
that they form a union and grow together to
make one plant.
Wedge
Graft
Approach
Graft
Grafting Terms
• Scion-the piece of plant at the top of the graft
• Rootstock-the piece of the plant at the root or bottom of the
graft
• Tools needed: knife, tape, wax
• Plants must be related to each other and normally in same
genus or family
• Examples: maples, fruit trees, sweetgum, pecan
Methods of Grafting
• If the scion and rootstock are the same size
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wedge
splice
whip and tongue
approach
Methods of Grafting
• If the scion is smaller than the rootstock
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cleft
side
notch
bark inlay
Budding
• A form of grafting when a bud is used
instead of scion
– patch budding
– T-budding
– Chip Budding
Chip
Budding
How to perform T-budding
Step 2
Step 4
Step 1
Step 3
Budding
• Successful budding requires that the scion (top) material
have a fully-formed, mature, dormant bud
• Rootstock has to be in condition of active growth “bark is
slipping”
• Refers to vascular cambium actively growing and bark can
be easily peeled from rootstock with little damage
• Example: rose
Tissue Culture (Micropropagation)
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A sterile environment is necessary for micropropagation
A good way to get the most plants in a short period of time
It will give you a plant identical to the parent plant
Examples: impatiens, many flowers, vegetable plants
Additional Terminology
• Corm – enlarged, bulb-like, fleshy structure found at the base of a stem. Usually
flattened and round.
– Gladiolus, crocus
• Rhizome – a creeping underground stem, usually horizontal, that produces roots and
leaves at the nodes.
– Canna, bearded iris
• Stolon – creeping above ground stem that grows horizontally and produces roots and
shoots at the nodes
– strawberry
• Tuber – Swollen, modified stem that grows underground
– potato
• Sucker – shoot or stem that originates from the roots
Advantages of Asexual Production
• Plants mature in a shorter time
• Budding is faster than grafting
• In trench layering, a plant forms at each node on a covered
stem
• Some plants do not produce viable seed
• New plants are the same as the parent plant
Disadvantages of Asexual Reproduction
• Some require special equipment and skills, such as
grafting
• Cuttings detach plant parts from water and nutrient source
• Some plants are patented making propagation illegal
The Uses of Biotechnology in
Horticulture
What is Biotechnology?
• The use of cells or components (parts) of
cells to produce products or processes
Methods
• Tissue culture or micropropagation
• Cloning
• Genetic Engineering
Tissue Culture
• Uses terminal shoots or leaf buds in a
sterile or aseptic environment on agar gel
or other nutrient-growing media to produce
thousands of identical plants
Cloning
• Genetically generating offspring from non-sexual tissue
Genetic Engineering
• Movement of genetic information in the
form of genes from one cell to another cell
to modify or change the genetic make-up
Benefits of Biotechnology
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Produce many identical plants in a short time
Increase disease and insect resistance
Increase tolerance to heat and cold
Increase weed tolerance
Benefits of Biotechnology
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Increase tolerance to drought
Improve environment
Increase production
Other genetic changes