The Art and Science

of Grafting

Adam R. WheelerAdam R. WheelerGraduate AssistantGraduate Assistant

University of VermontUniversity of Vermont

So What is Grafting?So What is Grafting?

- - Grafting is the ART of connecting two pieces of living plant tissue so that they will unite, grow and develop as one plant

Grafting TerminologyGrafting TerminologyScion - short piece of detached shoot

containing at least one dormant bud. The upper portion of the graft producing stems and branches

Rootstock (understock or stock) - lower portion of the graft. Produces the root system of the plant.

Vascular cambium - an area of actively growing tissue located between the bark (phloem) and wood (xylem). The cambium of scion must be in close contact with cambium of rootstock.

Callus - mass of parenchyma cells that develop from wounded plant tissues.

The History of GraftingThe History of Grafting

- - First documented by the Chinese as early as 5000 B.C. when Feng Li, a Chinese diplomat, began grafting peaches, almonds, persimmons, pears and apples as a commercial venture.

- Aristotle (384 -322 B.C.) and Theophrastus - Aristotle (384 -322 B.C.) and Theophrastus (371-287 B.C.) both wrote about grafting. (371-287 B.C.) both wrote about grafting.

- During the Roman Empire the Romans - During the Roman Empire the Romans were famous for their grafted olive treeswere famous for their grafted olive trees

- The Renaissance period (1350-1600 AD) - The Renaissance period (1350-1600 AD) saw renewed interest in graftingsaw renewed interest in grafting

- In the 16-17th century In the 16-17th century grafting was widely used grafting was widely used in Englandin England

- In the early 1800’s grafting became - In the early 1800’s grafting became common place in the United States. common place in the United States.

- Today grafting is used by many major growers to produce hundreds of different types of agricultural and ornamental plants.

So Tell Me How It Works!

What’s The Point Then?What’s The Point Then?

- Many plants (beech, - Many plants (beech, eucalyptus, fir, oak andeucalyptus, fir, oak andapple) root very poorlyapple) root very poorlyfrom cuttings.from cuttings.

- Consequently, clones of- Consequently, clones ofthese species are oftenthese species are oftenmaintained by grafting.maintained by grafting.

1) To Perpetuate clonesPerpetuate clones

- Japanese maples often form poor root systems - Japanese maples often form poor root systems when grown from cuttings and therefore must when grown from cuttings and therefore must be graftedbe grafted

- Some rootstocks can tolerate unfavorable soil pressure Some rootstocks can tolerate unfavorable soil pressure from disease, insects and nematodes better than the from disease, insects and nematodes better than the scion’s root system. scion’s root system.

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2) To Take Advantage of Rootstock Diseaseand Pest Tolerance.

- Wine grapes are grafted onto native muscadine - Wine grapes are grafted onto native muscadine grapes to prevent problems from nematodes and grapes to prevent problems from nematodes and phylloxera = yellow aphid.phylloxera = yellow aphid.

3) To Take Advantage of Rootstocks tolerance of poor growing conditions.

- Some rootstocks are able to withstand poor quality soils (compaction, poor drainage, dry, high salt levels) better than the scion’s root system.

4) Some Rootstocks Can Speed the Growth of the Scion Into Early Maturity.

5) 5) Some Rootstocks can increase plant Some Rootstocks can increase plant growth rate and reduce nursery production growth rate and reduce nursery production time.time.

- Some shade trees (like - Some shade trees (like Acer platanoidesAcer platanoides ‘Super ‘Super Form’) can grow more Form’) can grow more quickly if grafted than if quickly if grafted than if grown as a rooted cutting grown as a rooted cutting or even a seedling!or even a seedling!

6) 6) Grafting Can Be Used to Obtain Special Grafting Can Be Used to Obtain Special Growth FormsGrowth Forms

- With ornamentals, it is common to use an - With ornamentals, it is common to use an upright growing rootstock and a “weeping” upright growing rootstock and a “weeping” or “dwarf” scionor “dwarf” scion

- With fruit trees it is common to use a dwarfing rootstock to create a smaller sized plant

7) 7) Grafting Can be used to Repair damaged Grafting Can be used to Repair damaged treestrees

– Trees are often damaged from winter Trees are often damaged from winter injury, rodents, machinery, or disease.injury, rodents, machinery, or disease.

– Grafters can use a bridge graft or a Grafters can use a bridge graft or a technique known as inarching to repair the technique known as inarching to repair the damage.damage.

This method is used to:This method is used to:

– Change unproductive cultivars or Change unproductive cultivars or those no longer in demandthose no longer in demand

– Fix poor growth habitFix poor growth habit– Change cultivars that are susceptible Change cultivars that are susceptible

to insects of diseaseto insects of disease

8) 8) Grafting can be used to change cultivars Grafting can be used to change cultivars on established plants (topworking)on established plants (topworking)

What’s The Plan For Today?

Budding - a specialty form of grafting performed in late summer. The scion is small and typically only consists of a single bud.

Two Types of Budding

Working with T-budding

The End