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