What's a 30% reduction to you?

[Mesterh]

Depends really.

 

I remember doing work for an LA that included the entire tree (roots and all) when quoting percentages in reductions/thinnings etc. One of there 15% thins was what we originally would class as a 30%

 

A 30% reduction to me would be to reduction the height and width by 30% ie if 60 feet high reduce by approx 18 feet, theres usually not a lot left though at 30% (well in my book anyway)

[Dean Lofthouse]

Going on the mass theory it would mean that a small percentage reduction would leave the majority of trees with no leaf and result in masses of epicormic

[Doug Blease]

Last summer I had a lot of TPO job specs saying "reduction of total crown by no more than 2 metres." Apparently, too much over reducing going on trees in the city.

[paradise]

Last summer I had a lot of TPO job specs saying "reduction of total crown by no more than 2 metres." Apparently, too much over reducing going on trees in the city.

Setting that kind of limit makes sense to me because what it kind of does is limit the wound size. A 30% reduction in branch length on a big tree can leave huge wounds, whereas on mature trees (species differences aside) removing 2m would likely leave more or less the same wound size whatever the size of the tree.

[D Mc]

Going on the mass theory it would mean that a small percentage reduction would leave the majority of trees with no leaf and result in masses of epicormic

 

 

There is some logic to what you are saying, Dean. Picture this: you can remove every leaf off of a tree by hand (or an insect defoliation) and the tree will respond with normal growth replacement. That would be a 100% reduction if basing this theory by leaf surface.

 

If you remove all of the apical buds or remove live wood comprising more than your 30%, you will probably have exaggerated growth patterns or epicormic growth.

 

It is good to keep in mind that many of these are not hard and fast rules. Just guidelines that are species and situation specific.

 

Dave

[Mesterh]

Setting that kind of limit makes sense to me because what it kind of does is limit the wound size. A 30% reduction in branch length on a big tree can leave huge wounds, whereas on mature trees (species differences aside) removing 2m would likely leave more or less the same wound size whatever the size of the tree.

 

Thing is though on a large tree 2 metres would = "So what did I pay you for? I still have no light in my garden and the tree looks exactly the same"

 

I know its right ie smaller wounds etc but imo its usually a waste of time as it does nothing when you very slightly reduce a large tree apart from damage the tree and possibly shorten its life.

[arb culture]

Mesterh - that's what I meant when I said it depends on who's asking and why.

 

As D Mc says these are not hard rules.

 

30% reduction to you may mean something very different to a non arb client, or even to an enforcing tree officer. It's important to be specific and precise, and to consider why the reduction is being perfomed in the first place. Is it for sail effect reduction, overall shade alleviation, to clear a nice view...?

 

[Mesterh]

Yep your right:thumbup1:

 

The why is probably the most important bit IMO.

[Albedo]

To answer the question I pick © something else – that something else being – nothing – in that % figures for reduction are of no use to me.

 

The percentage thing may be given when, instructions have to be given on a job sheet for example, in this case it might be useful.

 

For me doing domestic work I always look for what the tree offers in terms of making it smaller. As I work to a rule of thirds whereby the secondary branch being cut back to has to be a third of the size of the primary branch. I look for at least 2 such points along the limb being reduced, so that a feathered effect is achieved with no obvious large stubs. My aim is not to force a shape or size onto it, but to work in this way with what the tree offers, in terms of suitable places to reduce to.

 

If the tree is not suitable you have the option of Reduction Via Thinning (RVT) whereby whole limbs are taken out, selecting the ones that are the longest, and leaving shorter ones thereby making the tree smaller (there is a bit more to RVT than this)

 

The two above techniques can be combined.

 

There are all sorts of possibilities for trees which have got away a bit:.

 

With a euc you might do something ugly to it

With a birch, you might fell and replant

With a large mature specimen, you might offer light reduction or thinning, depends on the scenario.

 

All the time you have to bear in mind that you are not overdoing it, in order to avoid sprouting. Species has to be born in mind too, If you don’t know from experience it’s a good idea to phone a friend so to speak and find out what the reaction is likely to be to what you want to do

[paradise]

I see what you're saying arb culture, and I realise that many clients would never accept 30% of the leaf area as the maximum reduction.

 

I guess my question was - recognising that we all end up doing work that isn't optimum for tree health and putting that aside - what is the 30% guideline figure for preserving tree health *meant* to mean?