Master Gardeners- Plant propogation
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Transcript of Master Gardeners- Plant propogation
PLANT PROPAGATION
Master Gardener
Training
Plant Propagation
• Sexual (reproductive)– SEEDS
– Maintains genetic variation = all offspring genetically different
• Asexual (vegetative)– Vegetative Parts
• stems
• roots
• leaves
• buds
– Produces CLONES = all offspring genetically identical
Propagation by SEED
• What is inside a seed?– embryo = baby
plant – food = called
endosperm
• Covered by the seed coat (testa)
Seed Terms
• Cotyledons = seed leaves– monocot, dicot
• Radicle = first root• Hybrids =
intentional crosses– F1 hybrids, F2
hybrids– Hybrid Vigor– Open Pollinated – Seed Strains
Dicot
Monocot
Requirements for Germination
• Moisture– if seeds dry out after they imbibe water,
they will perish
• Temperature– range needed varies depending on
species
• Light or Dark– some need light, others dark, many
don’t care
Overcoming Dormancy
• Many perennial and woody plant seed exhibit some type of dormancy
• Scarification
• Stratification - warm or cold
• Double Dormancy
Growing Plants from Seed• Vegetables and Annuals
– generally very easy– when depends on whether
cool or warm season
• Perennials– Some are easy - usually
begin in late spring, most will not bloom first years from seed
– some require stratification
• Trees and Shrubs– most require stratification,
scarification, or both
Saving Seed
• Many gardeners as well as small farmers save seed each year.
• Is this a good idea?
• Open pollinated seed- yes
• Hybrid seed- no
• Planted near GMO crops- no
Saving Seed Cont.• Fruit must be fully ripe (dry)• Avoid harvesting from diseased plants• Seed removed, washed and dried• Store in air-tight containers with anti-
desicants- some in freezer others at room temperature
• May treat with a fungicide to reduce pathogens
Seed Saving Cont.• Fruit trees, vines, etc will not come true to
variety• Native trees and shrubs will exhibit genetic
diversity• Flowering perennials- ditto• Open pollinated vegetables- fairly true if no
hybrid vegetables nearby• Heirloom annuals- mixed bag of results• Hybrids may germinate but not true to
original variety
Asexual Propagation - Cuttings
• Stem Cuttings - 4 types:– herbaceous = perennials– softwood = new growth, May-July
• wood snaps but has graduation of leaf size
• most deciduous shrubs
– semi-ripe = late summer - fall• most broadleaf evergreens, conifers
– hardwood = taken in winter • works for many deciduous shrubs
Basics of Cuttings
• Always take from healthy plants• When to take depends on plant -
research!• Avoid shoots with flower buds• Usually take cut just below a
node• Hormone may be helpful but not
always necessary• High humidity often necessary
Other Types of Cuttings
• Root Cuttings– Perennials with thick roots,
suckering shrubs• Take in mid-winter
• Often shoot emerges before roots grow
• Easy to overwater
• Make sure and get top end up!
• Leaf Cuttings– mostly only possible with
houseplants
LAYERING
• Induce rooting while stem is attached to the plant!
• Higher success rate, but slower
• Only possible with certain plants
Tip Layering
• Place tip of plant in soil.
• Mostly only used for Blackberries, Raspberries and relatives.
Simple Layering
• Layer portion of lower branch in soil.
• Wounding lower side of stem can be helpful.
• Most plants with low growing branches: roses, azalea, wax myrtle, oak leaf hydrangea, figs
• May take 1yr. +
Mound Layering (stooling)
• Possible with many low growing perennials, some shrubs - spirea, cotoneaster, shrub dogwoods.
• Mound soil during the dormant season.
Air Layering
• Houseplant and some woodies - azalea, camellia, magnolia, holly
• Pencil size stems in spring on last years growth in late summer on current growth
Other Asexual Methods
• Division– perennials, groundcovers
• Micropropagation - Tissue culture– extremely small portions of
plants (even a single cell) grown in culture on agar media in petri dishes in labs
Budding and Grafting
• Two genetically different plants are joined
• Scion and Rootstock
• Characteristics of both plants
• Avoid juvenility
Budding versus Grafting
Budding
Budding versus GraftingGrafting
Graft Union
Grafting and Budding
• Common Plants:– Fruit trees– Difficult to
propagate• Japanese Maple
– Roses– Weeping
Standards