Scottish Rock Garden Club Forum

Cultivation => Cultivation Problems => Topic started by: ian mcenery on December 12, 2007, 12:43:10 PM

Title: Helleborus thibetanus pest
Post by: ian mcenery on December 12, 2007, 12:43:10 PM
I have 3 plants of this hellebore in the garden 2 of which have been attacked for the last 2 years with the result that the flower buds have been destroyed. I think that the damage occurs at or just before the buds break through the ground. I have placed mouse traps, watered with slug and bug killer all to no avail. Maybe I was to late  but I wonder if anyone has any ideas what may be causing this as no other hellebore species or hybrids are affected? Maybe its just tastier than the others
Title: Re: Helleborus thibetanus pest
Post by: Maggi Young on December 12, 2007, 12:50:06 PM
Ian, might it be wood pigeons?
Title: Re: Helleborus thibetanus pest
Post by: mark smyth on December 12, 2007, 03:46:58 PM
the damage is very similar to the remains of snowdrop buds after the slugs/snails have had a go. I wouldnt let that amount of leaves lie over my emerging plants. Nice and cool for nasties
Title: Re: Helleborus thibetanus pest
Post by: Tim Murphy on December 12, 2007, 05:54:28 PM
It looks like slug damage to me too, Ian. I agree with Mark about the fallen leaves; if you turn them over, you'll probably find hundreds of tiny black slugs. They attack all hellebore species here. I have found to my cost that certain types of bark also provide the perfect environment for these slugs. I mulched a bed of Helleborus dumetorum with bark a couple of year ago and every plant emerged with damaged growing tips. I use a much finer grade of bark now and it has helped reduce the damage.
Title: Re: Helleborus thibetanus pest
Post by: Lesley Cox on December 12, 2007, 07:49:37 PM
In case it's a bird, maybe try a basket of fine netting over the plant for a few days until the attraction abates.
Title: Re: Helleborus thibetanus pest
Post by: Diane Whitehead on December 13, 2007, 07:00:00 AM
There are hidden cameras at bank machines and in malls.  I'm not
sure whether they are triggered by someone walking past them, or
whether they just take pictures at pre-set intervals.  I would like to
have a similar camera that will take pictures of my vulnerable plants,
 especially on horrible wet nights when I don't want to be out with a flashlight.
The camera would need to be weather-proof and I wouldn't put anything
good at risk.  Have you heard of anyone doing this?
Title: Re: Helleborus thibetanus pest
Post by: ian mcenery on December 13, 2007, 11:06:03 AM
Thanks for all your comments.
I thought Hellebores had  some toxins which made them less attractive to pests no other hellebores seem to be affected and I have many. Some slug or grub was my best guess originally as the damage if carried out below ground need only be small. I had considered mice but Maggi I hadn't considered wood pigeons so I will make my temporary cover a litle higher to see if that helps.. Lesley I have covers over now so if it is birds it will stop. The problem is if it does stop now will I have found the solution for next year? I can see world war 3 looming against all pests next year.


Tim and Mark it could be slugs but I treated the area with liquid slugit -great stuff by the way - so they must be toughies.  Tim it is especially interesting re your comments about composted bark as I dressed the whole garden with grit and composted bark about 3 years ago in addition to a large amount of compost (which I make each year). So perhaps I may go back to peat (did I really say that).

Diane I think you have the answer but with my luck the pesky creatures would eat something else out of the eye of the camera

I suppose I will just use the belt and bracers approach for next year ???
Title: Re: Helleborus thibetanus pest
Post by: Maggi Young on December 13, 2007, 12:29:11 PM
Diane, I believe that fairly inexpensive waterproof cameras are available now, so perhaps you could set up a system to watch over your treasures.... you may find a new career as a female David Attenbrough, in the field of nature photography... though he doesn't actually wield the camera, of course!  ::)

It might be fun to try this... worrying if you discover Saskwatch nibbling your shoots, though, eh?  :o
Title: Re: Helleborus thibetanus pest
Post by: Susan Band on December 13, 2007, 01:44:42 PM
Diane,
You could also leave it on during daylight hours to catch your flowers opening. With a web link you could see any flowers that open and go over when you are on holiday, away at work etc. ;D
Title: Re: Helleborus thibetanus pest
Post by: mark smyth on December 13, 2007, 03:15:03 PM
One my the buds from my plant has been eaten too. Pellets spraed across the garden now
Title: Re: Helleborus thibetanus pest
Post by: ian mcenery on December 13, 2007, 04:55:17 PM
Perhaps thibetanus is more tasty  than others but I leave someone else to try???
Title: Re: Helleborus thibetanus pest
Post by: Diane Whitehead on December 13, 2007, 05:48:27 PM
Sometimes one species of a genus is less toxic than the others.

For instance, deer will not eat any of my various species of Euphorbia,
but they have eaten a lot of E. mellifera.
Title: Re: Helleborus thibetanus pest
Post by: Lesley Cox on December 13, 2007, 08:38:16 PM
We have a "reality" TV thing here made at the Auckland zoo. Animal behaviour, new arrivals, departures, illnesses, zoo babies etc etc. All quite innocuous and feeling good (nothing is cuter than a tiny baby rhino). But last year someone took to dumping a dead cat at the zoo, in the same place, at night about once a week, if I remember rightly. A watch was kept but no joy so a camera was installed in a tree and programmed. Unfortunately I didn't see the following episodes so don't know whether the culprit was caught. This is sounding awfully like a joke where the teller has forgotten the punchline. Sorry.
Title: Re: Helleborus thibetanus pest
Post by: David Nicholson on December 13, 2007, 08:46:12 PM
There used to be a book '1001 uses for a dead cat' quite funny it was. Did you get it in NZ?
Title: Re: Helleborus thibetanus pest
Post by: Lesley Cox on December 13, 2007, 09:08:36 PM
We did David, and a very good book it was too. I gave a copy to a friend who was a cat lover. I don't think we've spoken since. ???
Title: Re: Helleborus thibetanus pest
Post by: jomowi on December 14, 2007, 08:24:47 PM
Looking at my H. thibetanus I also see damage.  It looks rather like birds to me, the alternative is mice or voles, we certainly get mice eating strange things like Brussel Sprouts in the winter.  Toxicity seems no problem since I have had mini Narcissus and Frit leaves grazed to the ground by field mice.  Invest in a mouse trap, some cheese and some chicken netting to keep the birds from the flowers and the traps.  I might also guess that the toxins are at low concentrations in the rather wet very early growth.

Brian Wilson  Aberdeen
Title: Re: Helleborus thibetanus pest
Post by: ian mcenery on December 15, 2007, 12:35:52 AM
Brian There were mouse traps but none caught nor any sign - my mice seem to be able to take the bait without getting caught for up to 3 times. I have covered in mesh doused in slug and bug killer. Next year I will start earlier with a preemptive strike on all fronts and see what happens
Title: Re: Helleborus thibetanus slug damage
Post by: Paul T on December 18, 2007, 12:23:24 PM
It's not that thibetanus is any less toxic than the other Helleborus, it is just that the critters know that it is more desirable and uncommon than the other ones that are around.  So they chose it just to be difficult.  It always seems to be the way.... if there is one super important thing they have this natural radar that picks it out of the crowd.  MY snails and slugs all know that the Weldenia candida is top priority to munch on, in fact they have literally crawled over snail bait to get to it! <sigh>

OK, so I'm sounding a tad paranoid.  But I am not paranoid because paranoia is when you THINK someone is out to get you when they actually AREN'T...... whereas I know that the snails ARE out to get me.  So, therefore I can't be just being paranoid!!!!!  ;D  Perfectly logical!
Title: Re: Helleborus thibetanus pest
Post by: Joakim B on December 18, 2007, 12:37:15 PM
Paul There is a saying I like
"Just because You are paranoid does not mean You are not followed"
A nice little thing to think about

Ian is the thibetansus earlier than the other Helleborus or in a different place? It can also be smaller and hence easier to eat or they (who ever that eats them) can be just evil >:)

Hope the measurements You have done has stopped the attacks
Kind regards
Joakim
Title: Re: Helleborus thibetanus pest
Post by: ian mcenery on December 18, 2007, 12:51:00 PM
Paul I am sure you are right about the slugs predilection for the rare. I think there is a rule which says "Pest damage is in inverse proportion to the size of the plant and in a direct relationship with its rarity". Always when I have a single crocus the flower is removed from the stem by birds before it flowers whereas a good group seems to avoid attack.  ???

Joakin the other hellebore plants have not been affected as far as I can tell and are close by. Both Thibetanus are separated by about 50 metres but the attacks seem to be over. I am convinced that much of the damage is in the very early stages and what I see now is because of the enlargement of the bud. Pesky critters !!!!
Title: Re: Helleborus thibetanus pest
Post by: zephirine on December 18, 2007, 01:48:56 PM
Well, if You had Haggishus x hybridus to eat at breakfast, lunch and dinner, every single day, and saw a nice piece of Steakus thibetanus right under Your nose mouth, would You actually resist and pass by?
Critters (even scottish critters :P) probably appreciate some change in the menu, from time to time! Not that the rare is necessarily better than the usual, it just tastes different! ;D
Zephirine
Title: Re: Helleborus thibetanus pest
Post by: Ian Y on December 18, 2007, 02:06:47 PM
Zephirine you are so right. Given the choice between eating from a good delicatessen or tesco I know where most of us would go.
Not that there is anything wrong with tesco but we all like a change and a taste of the exotic when it is on offer and that is what we are offering the slugs when we bring in the rare plants.
Title: Re: Helleborus thibetanus pest
Post by: ian mcenery on December 18, 2007, 02:45:19 PM
I think most critters (and even some humans) do many actions automatically. Having only some rudimentary brain power - the pests that is - having found something they like they will take a compass  bearing and return night after night climbing across often tastier morsels such as caviarus and smokus salmo trutta leaving all of the traps bait etc and leaving me scratching my head.
Title: Re: Helleborus thibetanus pest
Post by: mark smyth on December 18, 2007, 06:15:16 PM
we are forgetting about one hidden pest that will not come to any bait. The caterpillar of the Yellow Under-wing moth. It feeds at night
Title: Re: Helleborus thibetanus pest
Post by: Maggi Young on December 18, 2007, 08:17:15 PM
Mark, I thought, what is he on about.... so went a-googling to find info on said yellow underwing moth and discover that I am only TOO familiar with this caterpillar, i just did not know what type they were... know your enemy, as they say!
Title: Re: Helleborus thibetanus pest
Post by: mark smyth on December 18, 2007, 09:38:47 PM
yes the dreaded cut worm
Title: Re: Helleborus thibetanus pest
Post by: ian mcenery on December 19, 2007, 12:14:10 AM
Cutworm guilty or not guilty and will it stand up in court?? .

If you want to stop this creature my pest book suggests 2 chemicals both according to the net are Quote

"Banned in the UK, considered to have carcinogenicity and reproductive and developmental toxicity. It is a neurotoxin " NICE
Title: Re: Helleborus thibetanus pest
Post by: jomowi on December 19, 2007, 08:01:25 PM
If you pause to think about it pests have very little fresh green material available at the end of December and the prospect of protein rich pollen and energy rich nectar must be quite attractive.  Do Grey Squirrels eat flowers? at this time of the year they are digging little holes in the ground to find food (if i don't manage to make little holes in them first) and are widespread in the UK.

Brian Wilson Aberdeen
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