japanese knotweed introduction derek wells what is it? what does it look like? where did it come...
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Japanese knotweedJapanese knotweedIntroduction Introduction DEREK WELLSDEREK WELLS
What is it?What is it?
What does it look like?What does it look like?
Where did it come from?Where did it come from?
Where does it grow?Where does it grow?
Can it be killed?Can it be killed?
Do bugs kill it?Do bugs kill it?
Can it cause structural damage?Can it cause structural damage?
What does it look like?What does it look like?Green leaves with green and purple speckled hollow stemsGreen leaves with green and purple speckled hollow stems
What does it look like?What does it look like?
Can grow to over 3 m highCan grow to over 3 m high
What does it look like?What does it look like?
Creates shade out competing most other plants.Creates shade out competing most other plants.
What does it look like?What does it look like?
Cane like stemsCane like stems
What does it look like?What does it look like?It dies back over winter leaving a carpet of dead stems It dies back over winter leaving a carpet of dead stems
Where did it come from?Where did it come from?
A plant brought to the UK as an ornamental A plant brought to the UK as an ornamental in the mid 19in the mid 19thth Century. Century.
There are 3 species of Japanese knotweed There are 3 species of Japanese knotweed in the UKin the UK
1. Fallopia japonica – most widespread1. Fallopia japonica – most widespread 2. Fallopia sachalinensis –giant knotweed2. Fallopia sachalinensis –giant knotweed 3. Fallopia x bohemica -hybrid3. Fallopia x bohemica -hybrid
How and where does it grow?How and where does it grow?
It grows from vegetative propagation only It grows from vegetative propagation only mainly from Rhizome particles and it is said mainly from Rhizome particles and it is said that stems can take root also. that stems can take root also.
It has the ability to grow from very small It has the ability to grow from very small pieces and can grow in.pieces and can grow in.
Most soil typesMost soil types Most locationsMost locations Most water levelsMost water levels Seeds are infertile. Seeds are infertile.
Can it be killed?Can it be killed?
YES-it is a plant it can be killedYES-it is a plant it can be killed
Programmed spraying-using a Glyphosate Programmed spraying-using a Glyphosate based herbicide.based herbicide.
Stem injection using Glyphosate Stem injection using Glyphosate
Can it be killed?Can it be killed?
Stem injection- is a method of injecting neat Stem injection- is a method of injecting neat herbicide directly into the hollow stems of herbicide directly into the hollow stems of each plant. each plant.
This is best carried out during the flowering This is best carried out during the flowering period (September-October). period (September-October).
Stem InjectionStem Injection
Stem InjectionStem Injection
Stem Injection TrialsStem Injection Trials 17 17thth September 2008 September 2008
Stem Injection Trials Stem Injection Trials 22ndnd October 2008 October 2008
Stem Injection Trials Stem Injection Trials 13 13thth August 2009 August 2009
Stem Injection Trials Stem Injection Trials 77thth May 2010 May 2010
Stem Injection Trials Stem Injection Trials 77thth May 2010 May 2010
Can it be killed?Can it be killed?
Can I dig it out?Can I dig it out?
Dig and Dump is a recognised method, Dig and Dump is a recognised method, however disposal is very expensive as land however disposal is very expensive as land fill tax in this situation is very high. fill tax in this situation is very high.
Do bugs kill it? Do bugs kill it?
psyllid psyllid Aphalara itadoriAphalara itadori A bug from Japan that lays eggs on A bug from Japan that lays eggs on
knotweed leaves, grubs feed on leaves.knotweed leaves, grubs feed on leaves. ‘‘Bug Trial’ still at early stages, results not Bug Trial’ still at early stages, results not
proven as yet. proven as yet.
Structural DamageStructural Damage
It has been known for this plant to damage It has been known for this plant to damage the structure of buildingsthe structure of buildings
If allowed to get established it can exploit If allowed to get established it can exploit weak areas of built structures e.g. Cracks in weak areas of built structures e.g. Cracks in brickwork, Foundations, Tarmac etc. brickwork, Foundations, Tarmac etc.