Vine Weevil frustration
Palustris
Posts: 4,307
Just been going through my Auriculas in the poly tunnel. 15 pots so far with active vine weevil grubs in them. Really annoying as it is less than 2 months since every pot was soaked in very expensive stuff to kill off the things. It is also supposed to future protect the plants as well.
Since we a re moving house (hopefully) I do not want to take vine weevils with me to the new place.
Not sure whether to repot all the plants after washing the roots in fresh compost (big job there are over 400 of them) or just to throw them all away and start again with new plants next year.
How the heck do I stop this re-infestation? I have tried every type of stuff on the market, kept everywhere as clean as possible and disposed of every infected plant as I find them.
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Hopefully your new house will not have such a high population of weevils, Berghill!
My Heucheras suffered a severe attack last year - I lost a beautiful Heuchera 'Marmalade', which the bumblebees used to adore and nearly lost my favourite H. 'Silver Scrolls'.
There was only the merest piece of crown left of the 'Silver Scrolls', which my Mum managed to save by tying it down with raffia to the surface of just moist compost and cossesting it for a good few months.
This year, I drenched all the pots with Nemasys nematodes - so far so good, but I won't say too much for now!
If all goes well, I'll give them another application of Nemasys in the spring, just to make sure.
£1200 of plants thrown away is a bit of a leap though. We have decided that what I will do is when we get a date for moving (if ever) I will take a cutting from each plant, no roots so no weevils. Carefully labelled in 2 ins pots and take them. The originals can be thrown away, the pots washed out. Eventually the cuttings can be potted up and grown on to selling size.
I think we only just get away with having the Snail Lover's Society - if we developed the Vine Weevil Lovers Society we'd probably get hounded off the forum and told never to return!
What did you use that didn’t work?. I’ve always found Provado in pots to be effective, wouldn’t use it on the open garden, but pots are fine.
All the pots were soaked for 24 hours in Provado at the recommended strength. The grubs I am finding are all newly hatched.
I'm not a fan of pesticides so have never used Provado, but I know some people who have used it and they have reported the presence of larvae in the compost after application.
You must be one of the lucky few, Lyn!
It's my first year of using nematodes, so I am cautious about recommending them too soon - but so far I appear to weevil-free.
Fingers crossed.....
I only used Provado because I had some left over from previous purchase, before it was made known about its effects on bees.
Will try the nematodes in future.
Have one question about them. Can I use the nematodes before there are grubs. ie as a future preventative? In other words do they remain active in the compost until such times as the plants are attacked?
Berghill, there are a few ways you could use the nematodes. Unfortunately this time of the year the temperatures are too cool outside to use them effectively. On the flip side of this the grubs are also inactive at these low temps..
Some people apply nematodes for example once a month as a preventative method to ensure they are always present within the soil to counter any grub activity. This is quite an expensive method however, the nematoes without any prey will last around 3 weeks and eventually run out of energy.
You are best to apply in the spring and attack the grubs themselves with a good application. We have been using nematodes successfully for a number of years. Like pbff we try and avoid all pesticides where possible.
Hope this helps..
Berghill, I remember your photos of your Auricula collection........it would be heart breaking to lose them.
Hope you have success in dealing with the vine weevils.
The trouble with waiting until Spring is that by then the plants would be dead. Also we are hoping (and praying) to move from here at the latest by the end of February. For the moment I will just continue taking each plant out of its pot, examining the soil and repotting where necessary. It does not do the plants much good as at this time of year they do not make much in the way of new root.
Roll on the time when the fungus which kills the grubs becomes more readily (and cheaper) available.