Holes in Leaves in Bay Trees

artvandelay48

Hi,
We have three large boxes of Bay trees ( three trees to a box) that screen our balcony. For a while now, I have not been happy about the state of the leaves on it. Both the old and new leaves are full of holes. Is there a spray that I can get to stop insects eating the leaves?
Thanks,
Art

Ophiopogon

If the holes are almost perfect circles in and around the middle of the leaf and not at the direct edges than it is prob a shot hole fungus and not an insect.

Laurels can be very susceptible to this esp if they are under stress so make sure they are well watered and fed and any prune cuts are clean.

Also remove any fallen leafs and destroy elsewhere, good hygiene is a must to prevent the spread of the disease.

There is a fungicide you can get but I just can't think of the name of it...

artvandelay48

Ophiopogon wrote: »

If the holes are almost perfect circles in and around the middle of the leaf and not at the direct edges than it is prob a shot hole fungus and not an insect.

Laurels can be very susceptible to this esp if they are under stress so make sure they are well watered and fed and any prune cuts are clean.

Also remove any fallen leafs and destroy elsewhere, good hygiene is a must to prevent the spread of the disease.

There is a fungicide you can get but I just can't think of the name of it...

Thanks for the info. I will check to see how the holes are on the leaves. If the bays are on a balcony that is not covered, should I still be watering them regularly? I usually judge watering by looking at plants to see if they are wilting a bit. This is a bit difficult on the bays as they never seem particularly wilty.

I do prune them in the hope that they bush up but I use shears so presumably this is the clean prune that you mention. I am not very good at removing old leaves from the trees themselves but I don't let them sit in the planter for a prolonged period of time. The only feed I use is the slow release pellets.

Should I prune differently and change how I water and feed them?

Sonnenblumen

I recently posted on our Sunblog about looking after Bay Laurel plants (Lollipops) which might be of use to you:
http://www.owenchubblandscapers.com/news/?p=3309

Ophiopogon

In answer to OP, with the hot weather of late I would increase the amount of watering and try give more than you think as containers can dry out very quickly. And what I mean by clean pruning was to ensure there is no tearing so just a straight cut but if your using goods shrears it shouldn't be a problem.
The other thing is that it can take a while for the laurals to come back to health.

pegasus1

well i for one would like free professional advice on here instead of someones opinion...;) that said the wind,as in a drying wind will also dry out potted plants rather quickly, thats what my mum told me anyway...

also OP dont be lighting any bbq's near them as bay trees will go up in flames if a flame gets too near them......take a leaf and light it...away from the tree's mind you:rolleyes:

artvandelay48

Ophiopogon wrote: »

In answer to OP, with the hot weather of late I would increase the amount of watering and try give more than you think as containers can dry out very quickly. And what I mean by clean pruning was to ensure there is no tearing so just a straight cut but if your using goods shrears it shouldn't be a problem.
The other thing is that it can take a while for the laurals to come back to health.

Thanks for the advice. I had a closer look at the leaves and the holes appear to start from the edge not from the middle. However there do seem like some dried black bits on the leaves and the holes are more prevalent on the new growth (but not restricted to the new growth). Does this still indicate fungus?

Ophiopogon

It still sounds like shothole fungus to me...generally dark brown to black spots show first and than become shothole like damage. It can occur all over the leaf. does it look a bit like this shothole

If not this it could be vine weevil and this would show like the leaf is being eaten from the edge.

Is there any chance you could post a picture?

artvandelay48

Ophiopogon wrote: »

It still sounds like shothole fungus to me...generally dark brown to black spots show first and than become shothole like damage. It can occur all over the leaf. does it look a bit like this shothole

If not this it could be vine weevil and this would show like the leaf is being eaten from the edge.

Is there any chance you could post a picture?

Yeah, I think it is shothole. I have attached a couple of pics.

So, to get rid of it, I need to water 2-3 times weekly, clean up all the dead leaves, and feed it regularly. What type of feed should I use and how often? I currently use the slow release pellets but I only put them in the pots occasionally. Should I use another type of food?

What sort of time frame should I expect to get rid of it?

Ophiopogon

ok that actually looks more like Vine weevil damage to me.

Adult vine weevils are beetle like insects the feed on and around the leaf margin, this create the kind of notch like bite marks that I think I'm seeing in your photo.

The adult itself only creates superficial damage, however, its their larve that could eventually kill the plants by eat the roots.

If you could go out at night with a torch and look on and around the plants you should be able to see the adult vine weevils in action and you can remove and kill them.With that amont of damage if it is vine weevils they should be fairly visable. They hide in dark cracks during the day but also under the lips of containers themselves so if possible give the pots and surrounding area a good clean with soapy water. If you do see the adults though I would get some nematodes and apply to soil to kill off the larve.

For now I would remove all damaged leafs. Continue to water 2 to 3 times a week but try water directly into the soil and not on the leafs - this will reduce the possibility of shothole fungus as well. As another poster said consider moving of protecting from harsh wind if there is any. Also, in winter protect from frost. your feed should be fine as in IMO bays are not particulary hunger but be careful not to overfeed, just add as the pack suggests.

I think you could be looking at up to a year before it recovers.

artvandelay48

Thanks Oph, I'll check tonight and report back. Really appreciate all the help.

artvandelay48

Okay, I checked the plants last night and they have vine weevils. I bought some of this stuff: http://www.diytools.co.uk/diy/Images/DB_Detail/_68461__185246__.jpg

Does this stuff work?

Ophiopogon

To be honest I don't know the product so I can't say if it works...I did look it up it but I couldn't see any feedback just recommendations.

I would use nematodes as I don't like insectices myself but if you have already bought than use it.

The larve come out in autumn and could distory your plants completely so definitely start some sort of control. For now though I would contuine to pick off and kill any adults you see.

Good luck though as these are little ba$tards!!

gardenman77

Bay laurels in pots attract vine weevil like bees to honey. To save these plants.

1: Repot into fresh compost. The roots will be badly damaged by the grubs laid last year and in the spring, repotting and feeding with high Phosphorous fertilizer will encourage root development.

2: Use traps to catch weevil adults. A pot turned upside down stuffed with straw is a great way. The adult weevils only feed at night and hide during the day. Warm dark straw will attract them all! In the morning dump the straw with the weevils and go again until none are left!

3: Use nematodes (available in most garden centers). Only useful to apply in late April and early September as this is the time the larvae are active. Applying in mid summer is a waste of time. Also be very careful with moisture level of peat for few weeks after applying water. If it drys out, the nematodes will die. If it is too wet, they will become immobile, be unable to feed and die.
Apply in autumn and next spring to kill next generation.

4: prune away unsightly foliage. Bays can take a pruning quite well and will resprout beautifully.