I have a row of Laylandii planted last year, so far they are 3-4' high.
They were over run with weeds last summer and I sprayed carefully around
them with Round Up weed killer or so I thought. Some appears to have got
on one of the trees and the top half has gone brown and looks dead.

What's the best thing to do, cut off the brown or wait for new growth
from the brown stem?

TIA.

On 20/03/2016 10:59, Steph wrote:
I have a row of Laylandii planted last year, so far they are 3-4' high.
They were over run with weeds last summer and I sprayed carefully around
them with Round Up weed killer or so I thought. Some appears to have got
on one of the trees and the top half has gone brown and looks dead.

What's the best thing to do, cut off the brown or wait for new growth
from the brown stem?

TIA.
You will be extremely fortunate if they sprout green from the brown. One
of the problems with leylandii is they do not regrow on old wood. As
they are prone to dying off in cold winds they are often unsightly.

"Chris Hogg" wrote

Steph wrote:

I have a row of Laylandii planted last year, so far they are 3-4' high.
They were over run with weeds last summer and I sprayed carefully around
them with Round Up weed killer or so I thought. Some appears to have got
on one of the trees and the top half has gone brown and looks dead.

What's the best thing to do, cut off the brown or wait for new growth
from the brown stem?

TIA.

If it really is just the top half, then there's hope, but it's no use
waiting for the brown bit to sprout. Leylandii don't shoot from old
wood, which is why you should never cut back a Leylandii hedge into
the brown interior, as you'll likely kill it. However in this case, if
it's just the top that's gone, then cutting out the dead wood will
allow the living part lower down to grow up and fill the space. Of
course, rather than just having a single stem or trunk, you'll have
several, although one may eventually dominate. You could put a stake
in and deliberately train one of the lower stems into an upright
position, when it will become the leader and grow away.


As hedges should not be more than 2 metres high, unless you want neighbour
and then Council problems and the expense that entails, it won't be long
before you will need to start taking the tops out. The last thing you need
is for them to grow well above 2 metres and then have to lop off the tops
when you will be back into brown old wood and it will always look very
unsightly. With Leylandii, as it will not sprout from brown old wood, you
should never cut into anything that is not green, so it's a case of triming
a number of times a year from now on to shape you hedge and keep it under
control. Leylandii has to be the most work, hedge wise, if it is not to look
dreadful and /or take over a lot od space.
--
Regards. Bob Hobden.
Posted to this Newsgroup from the W of London, UK

On 20/03/2016 17:37, Chris Hogg wrote:
On Sun, 20 Mar 2016 10:59:28 +0000, Steph wrote:

I have a row of Laylandii planted last year, so far they are 3-4' high.
They were over run with weeds last summer and I sprayed carefully around
them with Round Up weed killer or so I thought. Some appears to have got
on one of the trees and the top half has gone brown and looks dead.

What's the best thing to do, cut off the brown or wait for new growth
from the brown stem?

TIA.

If it really is just the top half, then there's hope, but it's no use
waiting for the brown bit to sprout. Leylandii don't shoot from old
wood, which is why you should never cut back a Leylandii hedge into
the brown interior, as you'll likely kill it. However in this case, if
it's just the top that's gone, then cutting out the dead wood will
allow the living part lower down to grow up and fill the space. Of
course, rather than just having a single stem or trunk, you'll have
several, although one may eventually dominate. You could put a stake
in and deliberately train one of the lower stems into an upright
position, when it will become the leader and grow away.

I'd be inclined to dig it out and replant, though it does depend on how
close you planted them and how tall you want your hedge.