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How much to trim back Portuguese Laurels badly attacked by vine weevils?
Skylark001
Posts: 75
Over the last 2 summers 100s of vine weevils ravaged our Portuguese
Laurels, which now look straggly and bare, except for the highest tips.
So I'm thinking of cutting them right down in 2 weeks' time, so that there's only about 9 inches left above the rims of the pots.
I hope that if I cut them right down, they'll bush with much fresh growth this spring and summer, and then if I keep gently trimming their tips, they'll eventually become tall and thick. Ideally we want a screen of dense green, and not to be able to see the glass panels behind the laurels.
Would YOU cut them down as low as I'm planning to do?
Or would you cut them down even lower?
Or not so low?
Or perhaps only the tips at the top?
There are bound to be vine weevil grubs coming out of hibernation in the coming months, so I'm planning to spray new growth with a strong vine weevil spray from May to October, and then see if these shrubs can be saved.
If not, then they'll all just have to be replaced with shrubs which vine weevils avoid. But of course I'd rather not have to go to all that bother and expense.
Here are two photos of their current state:
All good advice will be most gratefully received!
Thank you.
So I'm thinking of cutting them right down in 2 weeks' time, so that there's only about 9 inches left above the rims of the pots.
I hope that if I cut them right down, they'll bush with much fresh growth this spring and summer, and then if I keep gently trimming their tips, they'll eventually become tall and thick. Ideally we want a screen of dense green, and not to be able to see the glass panels behind the laurels.
Would YOU cut them down as low as I'm planning to do?
Or would you cut them down even lower?
Or not so low?
Or perhaps only the tips at the top?
There are bound to be vine weevil grubs coming out of hibernation in the coming months, so I'm planning to spray new growth with a strong vine weevil spray from May to October, and then see if these shrubs can be saved.
If not, then they'll all just have to be replaced with shrubs which vine weevils avoid. But of course I'd rather not have to go to all that bother and expense.
Here are two photos of their current state:
All good advice will be most gratefully received!
Thank you.
0
Posts
If you do have weevils then the most important thing is dealing with the grubs, they can kill the plant by eating the roots. I would suggest trying the nematode method to get rid of the grubs. Once that is done you can prune your laurel fairly heavily, by about 2/3rds. Sounds drastic but once the plants are healthy they will soon bulk up again.
I think your shrubs have wind damage and wind scorch. The shrubs are crushed into very thin planters and at that height, and lack of early pruning to maintain bushiness, it's been possibly battered by the winds. I think the planters need to be a bit larger to sustain the type of coverage you are expecting. They need consistent watering and care to be planted in such small planters. If you want to maintain the hedge, it could be quite a challenge.
2/3rds doesn't sound too drastic to me. Used to have a massive garden and know that some bushes can be cut practically to ground level and will respond positively and thrive. But never had Portuguese Laurels before. So I'd like to be SURE of what will happen if I cut the bushes really low.
100% sure it was vine weevils, steephill, because each evening last summer I shook 100s of the devils from those bushes onto the adjacent paving, then quickly snatched them up with a bit of loo paper, squashed them flat, and disposed of about 20 per night down the loo! The evening tally was quite a joke. "How many tonight, love?" We took it in turns. "Weevil Patrol"!
The infestation was severe. Weevils adore compost in pots, so easy to burrow into, and particularly in warm positions. The reason why the bushes are still alive and why they have some leaves on them still is that we were onto the problem from the start. Three applications of nematodes at different times, as well as a spray onto the leaves. The nematodes were a big disappointment. Expensive, applied as directed, they should have done the job. Subsequently learnt that Swansea University researchers found that a third of nematodes in each pack are dead upon arrival! Lord Heseltine called a Vine Weevil Summit on his estate two summers ago, at exactly the time our whole street was infested. There's a video of the conference online. Basically there isn't a single product available at the moment which will see the devils off 100%, due to pesticide regulations.
Here's a snap I took last summer of the devils' favourite tucker in our street! Thankfully we don't have any of these shrubs in our own garden, but pity those who do.
Just prune the shrubs down if you want to maintain dense coverage, but I stand by my earlier comments, growing Portuguese Laurel in such thin planters will mean high maintenance and keeping it looking in tip-top conditions will be quite tough.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.
Of course I realise that there will definitely be SOME weevils appearing again in May, and that they'll want to eat, and so if the only foliage is low that'll suit them fine. Not far to climb for dinner!
Anyway, how low would you cut them down?