Clump planting to ease spread of pests

[europeantrees]

Having been asked about introducing clump planting patterns in the design of a peri urban planting project, I was told that this helped ease the spread of pests and pathogens, the latter is arguably a misconception but there is research to suggest that clump planting patterns can actually prevent rapid succession of pests - in particular processionary moth. Is this yet a great problem in the UK?

 

Landscape aesthetics aside is there anyone here who can help me with this one - is there any experience in the UK or elsewhere to suggest that clump planting will if nothing else help with future management of new planting.

 

I have not made up my mind and am still dubious about close planting of trees in an urban environment - thanks

 

Pip Howard

European Trees

[Fungus]

Having been asked about introducing clump planting patterns in the design of a peri urban planting project, I was told that this helped ease the spread of pests and pathogens, the latter is arguably a misconception but there is research to suggest that clump planting patterns can actually prevent rapid succession of pests - in particular processionary moth ... is there any experience in the UK or elsewhere to suggest that clump planting will if nothing else help with future management of new planting. I have not made up my mind and am still dubious about close planting of trees in an urban environment

 

Pip,

1. In a (natural) forest situation with trees in different phases of the tree species specific life cycles, root-root contact of same species trees in tree species specific ecosystems both has positive and negative consequences : positive being a single tree exceding endo- and/or ectomycorrhizal defensive system as part of the tree species specific forest soil food web and negative being roots providing a stepping stone for (secundary) root parasites or pathogens such as (rhizomorphs of) Armillaria species or Ceratocystis platani (Platanus) once the trees are in poorer condition because of (mechanical) root or buttresses damage, compaction, drought, nitrification, salt intoxication or above ground plagues or pests.

The positive aspects are hardly ever achieved in (peri) urban environments, the negative aspects are standard for any urban environment.

2. Most (mining) moth species cannot fly very far, so clump planting facilitates fast spreading over short distance, which is the case in The Netherlands with OPM travelling along oak lanes while "jumping" from tree to tree.

[Fungus]

succession of pests - in particular processionary moth. Is this yet a great problem in the UK?

 

Pip,

Concerning the present situation in the U.K., see the latest OPM update and Oak Processionary Moth.

And adding to my former post on clump planting of trees. Always imply the characteristics of the natural tree species specific habitats or ecological niches the tree species is part of or dominates in analyzing and determining what a tree species needs to thrive and survive in an "outside" forest, i.e. urban situation.

[europeantrees]

Thank you Gerrit, you have confirmed my personal thoughts. The problem being that a particular designer had dragged some academic text from the internet to back up his 'urban woodland design'. The worsening scenario we have with regards urban planting is the designer - 90% of the time we can work side by side, but occasionally the plans come through via a third person, the client themselves, who have been sold a wonderful and utopian image which we simply cannot realise - when this is referred to the client and they seek an explanation from the designer (increasingly we are seeing less well qualified designers - landscape architects are being shunned in favour with those who can simply talk the talk and draw a pretty picture!) and the designer can download any form of academic (sometimes dubious) reference material to win his argument with not much hunting around on google. I picked up on your thread with regards mychorrizae in which you challenged someone who had fallen into the same trap and am grateful for a back up here.

 

For me the idea of clump planting or any mimic of progressive rural planting is not a good idea in the urban environment particularly when the soil, (if you can even call it that), will change dramatically in such a small space - usually from cement to 'canine' effluent in the space of 2 metres.

 

Pip Howard

European Trees

[Fungus]

'urban woodland design' ... designer (increasingly we are seeing less well qualified designers - landscape architects are being shunned in favour with those who can simply talk the talk and draw a pretty picture!)

 

Pip,

Nothing new there then, as in The Netherlands there also is an ever increasing number of landscape architects or designers, who consider themselves to be "artists" first, producing planting plans without having a clue of forest ecology, let alone of the tree species specific ecosystems and life cycles, nor of the tree species specific soil food webs including mycorrhizal fungi.

And we have television programs on gardening hosted by "professional gardeners" with own websites and books, who are payed for recommending all kinds of commercial products "improving" growth and health of trees, including mycorrhiza preparations.

[europeantrees]

Very much a universal problem. Further more the peripheral and media sectors of the horticultural industry are very much culpable of perpetuating the spread of pests and pathogens by way of ignoring the fact that horticultural trade is guilty of introducing many of these new pests and pathogens into the landscape - worse still I recently heard a gardening journalist state 'the forestry industry must be held to account for not stopping the spread of threats [P. ramorum] to the garden heritage of England'!?!

 

Pip Howard

European Trees