I. WHAT IS LAYERING

    -A propagation method by which adventitious roots are induced on a stem
        while it is still attached to the parent plant

II. FACTORS AFFECTING THE SUCCESS OF LAYERING

    A. Nutrition

    B. Stress    -use of mist (water stress detrimental)

    C. Stem Treatments
            -Bending, cut, notching, girdling
            -Interruption of downward translocation of organic compounds
                (carbohydrates, auxin, rooting cofactors)

    D. Light Exclusion -prevent destruction of auxin
            -Blanching ----- covering of an intact stem
            -Etiolation ----- due to shoot development and elongation in the absence of light

    E. Physiological Conditioning
            -Movement of carbohydrate
            -Seasonal growth style

    F. Rejuvenation
            -Rooting at the base of new shoots

III. USES OF LAYERING

    A. Multiplication of plants that reproduce naturally by layering
            -Black raspberries, trailing blackberries

    B. Propagation of plants whose cuttings do not root easily
            -Filberts
            -Muscadine grapes
            -Mango, litchi

    C. Producing a large-sized plant quickly
            -Ficus elastica

    D. Propagation of plants without propagation facility
            -use of outdoors, large plants

IV. DISADVANTAGES

    A. Labor intensive

    B. Not cost efficient

    C. Mass propagation often difficult
 

V. TYPES OF LAYERING

    A. Tip layering
            -Use of succulent branches with tips burried in soil
            -Blackberries, raspberries

    B. Simple layering
            -One-year-old shoots
            -Flexible braches are bent down and burried in the middle
            -Filberts, dieffenbachia, many other plants

    C. Serpentine layering
            -Similar to simple layering
            -Branch is covered at multiple sites
            -Muscadine grape, clematis, wisteria

    D. Air layering
            -Girdle the bark of a stem at the site desired for root initiation
            -Use one-year-old stem
            -Growth regulator application to wound site, wrap with poly film
                and stuff sphagnum peat moss between film and girdle
            -Ficus, monstera, croton, mango, citrus, philodendron, dracaena,
                many tropical plants

    E. Mound layering (stooling)
            -Cut back stems in spring to the ground level
            -When new shoots develop, put a soil mound to cover the bases
            -Plants are separated after rooting
            -Apple rootstocks, cashew, pecan, many fruit trees

    F. Trench layering
            -Bury a branch longitudinally in a trench
            -Shoots emerge from nodal points
            -Difficult-to-root woody plants