Propagation in Plants Horticulture I Unit 4.02

Two Types of Propagation Sexual Asexual

plant propagation vocab Corm – an enlarged, bulb-like, fleshy structure found at the base of a stem Rhizome – a creeping underground stem, usually horizontal, that produces roots and leaves at the nodes (ex – cannas and bearded iris) Stolon – a creeping above ground stem that grows horizontally and produces roots and shoots at the nodes (ex – strawberry) Tuber – a swollen, modified stem that grows underground (ex – potato) Sucker – a shoot or stem that originates from the roots

Sexual Propagation Starting plants from seeds

Germination Rate The percentage of seeds that sprout (75 out of 100 = 75%) Can be affected by temperature and moisture Can vary depending on type of plant and quality (viability) of the seed https://www.youtube.com/watch?v=TE6xptjgNR0

Seed Viability The seed’s capability of growing or developing Affected by temperature and moisture Embryo Seed Coat Endosperm

Planting Seeds How deep to plant seeds depends on size of seeds Plant seeds no more than 1 ½ times the diameter of the seed Larger seeds are planted deeper Smaller seeds are planted shallow (ex – petunia seeds are tiny) Water small seeds from bottom by soaking to prevent burying them

Seedlings (small plants) The first set of leaves are called cotyledons Monocots produce one seed leaf Dicots produce two seed leaves

Seedlings (small plants) 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 https://www.youtube.com/watch?v=V1-K7qpuGYY

Advantages of sexual reproduction It is the fast way to get many plants It is easy to do It is 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 seed Marigold Impatiens Begonia Coleus Salvia Shasta daisy Pansy

Asexual propagation Starting plants by means other than seed Cuttings Layering Division Separation Grafting Budding Tissue culture

Cuttings Stem Leaf Root

Stem Cuttings Start with sterile flats, soil, and tools Must include a node Node is the point along a plant stem where leaves or other stems are attached Internode is the area between two nodes

Stem cuttings Cutting is taking a 4-6 inch piece of the plant and forcing roots to grow Using hormones and dipping the cutting in fungicides help speed up rooting Rooting media should be about four inches deep

Stem cuttings https://www.youtube.com/watch?v=71dYCsVAL8k Herbaceous plants are soft tissue plants Geranium, impatiens, begonia, coleus Woody plants are plants that produce woody tissue Holly, abelia, rosemary https://www.youtube.com/watch?v=71dYCsVAL8k

Gather all materials needed Stem Cuttings-Step 1 Gather all materials needed

Cut 3 to 4 inch shoot from stem tip Stem Cuttings-Step 2 Cut 3 to 4 inch shoot from stem tip

Remove lower leaves from the shoot Stem Cuttings-Step 3 Remove lower leaves from the shoot

Dip cut surface in rooting hormone Stem Cuttings-Step 4 Dip cut surface in rooting hormone

Thoroughly moisten rooting medium Stem Cuttings-Step 5 Thoroughly moisten rooting medium

Stick one or more cuttings in rooting media 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.

Once rooted, cuttings can be separated carefully and transplanted Stem Cuttings-Step 8 Once rooted, cuttings can be separated carefully and transplanted

Leaf cuttings https://www.youtube.com/watch?v=lVaZI1Nrgxo Usually propagated from herbaceous plants Midrib vein must be cut in order to make roots form Plants that can start from leaf cuttings: African violet, philodendron, snake plant, jade plant https://www.youtube.com/watch?v=lVaZI1Nrgxo

Root cuttings https://www.youtube.com/watch?v=POfTI4oWObo Should be spaced three inches apart in rooting area A sand, vermiculite or perlite mixture is a good media for root cuttings The best time of day to take a stem, lead, or root cutting is early morning because the plants have more moisture Plants that can be started by root cuttings: Hosta and daylily https://www.youtube.com/watch?v=POfTI4oWObo

Layering Air layering Trench layering Mound layering

Air layering Make an incision at the node of a branch Dust with rooting hormone, place sphagnum moss in plastic and wrap around the incision forcing roots to grow on the stem Once roots form, remove below the new roots for a new plant Ex) decora rubber plant and weeping fig https://www.youtube.com/watch?v=qviLRmiqrs8

Trench layering Cutting a trench and laying a branch in the trench Types of trench layering are simple, tip, and serpentine Ex) grapes and clematis https://www.youtube.com/watch?v=ZzJjGXgw7kI

Mound layering Mounding the soil on a branch Ex) azalea

Division Cutting apart rhizomes, tubers, runners, stolons, or suckers to get new plants Used on plants that grow in clumps Ex) hostas, daylilies, irises, some grasses

separation Separating natural structures of a plant without making a cut Ex) bulbs and corms

grafting Joining separate plant parts together so that they form a union and grow together to make one plant Tools needed – knife, tape, wax Plants must be related to each other and normally in the same genus or family Scion is the piece of plant at the top of graft Rootstock is the piece of the plant at the root or bottom of the graft Ex) maples, fruit trees, sweetgum, pecan https://www.youtube.com/watch?v=JUusOkwM0jM

budding A form of grafting when a bud is used instead of a scion Methods of budding Patch budding T-budding Chip budding Ex) rose Step 2 Step 4 Step 1 Step 3

budding Successful budding requires that the scion (top) material have fully-formed, mature, dormant buds and that the rootstock be in a condition of active growth such that the “bark is slipping” which means that the vascular cambium is actively growing, and the bark can be peeled easily from the stock piece with little damage

Tissue culture Also known as micropropagation A sterile environment is necessary for micropropagation (biotechnology) It is 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 Ex) impatiens, flower and vegetable plants

Advantages of Asexual Reproduction Plants mature in a shorter time Budding is faster than grafting In trench layering, plant forms at each node on covered stems Some plants do not produce viable seeds New plants are same as 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