Conifer Conundrum.

[Slime]

An old lady friend of mine has asked me to trim her conifers, (I think they're conifers), as they now block out her sunlight in the afternoons.
There are a fair few of them, no problem, but when I asked her how much she wanted trimming she said about 25' off each of them!!
Will this lead to their death or will they take that degree of shortening?
Thanks in advance, people.

Slime.

Oh, I'll try and post a couple of pictures next week.
Happy Christmas to all.

 

[JohnD]

I find you can cut the tops off without killing them. One of more of the branches below the cut may start to grow upwards. Or you may get disease in the cut, slowly killing the tree. 25' is a lot to cut off, so they are quite likely to die.

If you cut branches off and leave a bare trunk, they will mostly not grow back (if you cut them mostly back to twiggy stumps, some might, with luck)

Notionally, if you scratch the bark where you intend to cut them, and it's green underneath, you have more chance of regrowth than if it's brown.

Leylandii are particularly prone to dying back after pruning, which is good, as it gets rid of the horrible things.

You may find there is sticky sap which hardens on your saw and makes it hard to work.

 

[lostinthelight]

What percentage of the height does 25 represent and remember the next time they are cut there WILL be multiple branches to cut as the rest of the regrowth will try to become dominant to maintain the species normal shape .
If this is not the first time they have been reduced you could be dealing with multiple stems at height which is a dangerous job and best left to those who are skilled in such work.

litl

 

[Notch7]

An old lady friend of mine has asked me to trim her conifers, (I think they're conifers), as they now block out her sunlight in the afternoons.
There are a fair few of them, no problem, but when I asked her how much she wanted trimming she said about 25' off each of them!!
Will this lead to their death or will they take that degree of shortening?
Thanks in advance, people.

Slime.

Oh, I'll try and post a couple of pictures next week.
Happy Christmas to all.

Leylandii cant be cut below any green shoots, it wont regrow as it doesnt have active buds in the brown section. If the tree is currently 30'0 and you 'trim' off 25'0 you will have a 5'0 dead stump left

25'0 is major work which to me falls well into professional territory. The pile of stuff will be colossal aside from the danger element.

 

[Diver Fred]

Rather than asking how much do you want off you need to ask/know "how high do you want them to finish up?"

Then have you space to drop the excess in one peice?
Is their other properties around that may be damaged? (i.e. do you have suitable insurance?)
What will you do with the green waste and the thin brown waste?
Are you prepared to shift or transport large quantities of waste to the tip? (it's unlikely you will be able to burn it in situe.)

If the above questions can answered favorably then :-
Do you have strong ladders? - one to reach most of the way up the tree and one long enough to be just over the the final height?
Are you happy using saws at height?
Do you have some suitable (20mm or thicker) rope?
Are you happy you have assistance that can control the interested spectators?
Are you happy you have assistance that can control the fall? (thats the direction not the speed)

Think about it
(& BTW - I'm not a Tree Surgeon)

 

[dishman]

As per above.

You can lop the tops of to a desired height. This should not kill them unless you lop them really low. Maybe 1/3 off their total height is a good start.

Regarding pruning the sides and general tidying. This is the tricky bit. If you are too aggressive, you will pretty much ruin them....forever.

In terms of cutting and shaping. Only cut a thin layer of new green growth. So shape and cut back, you must do this regularly and in small amounts.

If you cut back too much, you will just end up with a dead looking conifer....similar to this:

Conifers with patches like that can also be suffering from an infection of aphid larvae which burrow into the base of the green leaf and slowly kill it. If not too far-gone, it requires a liberal spraying every few weeks of horticultural soap in spring to resolve.


Furthermore, If you cut back whole branches to the trunk in mature/existing areas (i.e low down on the trunk) , they will never sprout again....ever.....so you will end up with permanently bare areas .....like this:

So treat them carefully, and shape over a long period of time. Regular light trimming will mean a tighter growth, and you can shape them nicely.

We had two large conifers in the front. We used to lop the tops every few years. They looked like flat tables for a while, but new branches soon sprout and start growing upwards.

---


One other technique that really helps refresh them, is to rake them out. Basically bash and rake the sides with a hard pronged grass rake. Raking upwards in the direction of growth is the way to do it. Raking down will just bend the branches out.

As people trim conifers/laylandii, the dead stuff gets trapped within the branches. Overtime this ends up forming a thick layer of dead matter. If you lightly rake it out, it is amazing how much will come out. This will allow better airflow and more light penetrate and eventually encourage better growth.

I was quite aggressive with my rake out this spring and removed half a wheelie bin of dead matter from a 3metre section of 6.5ft laylandii.

It took a while to recover but looks much healthier now.

 

[dishman]

I would also suggest, that considering you imply the current height is quite considerable (i.e the plan to remove 25ft) that unless you have the correct equipment, you let a pro remove the initial height. If you do, avoid the vans that tour around areas looking for work and ring someone registered on the arb website.

https://www.trees.org.uk/ARB-Approved-Contractor-Directory

As wgt52 points out, you have a lot to consider in terms of safety of yourself and others, not to mention being able to dispose of the waste. When you get the stuff to ground level, you will soon realise how much you actually have to dispose of and it will seem a lot more compared to when it was on the tree.

On my 3m run of laylandii I recently cut the tops. These were about8.5ft, which I reduced to 6.5ft, (so 6ft of waste). At ground level it looked twice as much compared to when on the tree.