Vine weevil nematodes

debs64

Hi all, tried to find a discussion on these but couldn’t so here goes. I am planning to grow heucheras this year in pots and I have been plagued with vine weevil in the past so wondered if the nematodes were worth trying. 

I found the slug nematodes excellent so that’s encouraging. Anyone got any experience with the ones for vine weevil? Any advice gratefully received.
Any tips? Are they like slug nematodes and need a certain soil temperature?
Thanks 

Fairygirl

Yes - they all need appropriate temperatures to be effective, which is why I don't bother. It's too late by the time soil warms up. 
Many people find a thick layer of grit on the top of pots helps prevent the eggs being laid. 

Sheps

I have used them in the past and ordered some more for May, but I've always had the damage caused by the adults, so as to whether they work who knows, but I've never had any issues caused by the grubs, so maybe they do.

Like Fairy says, a thick layer of grit is the way to go.

I did all my pots last year.

bédé

Always had a thick layer of grit.  It never stopped Wine Veevils!  And aren't nematodes expensive?

debs64

The nematodes are not particularly expensive if you don’t need loads and probably work out cheaper than buying new plants but I will definitely look at grit. Are we talking pea shingle size or larger? 

Thanks for all the advice @Fairygirl and @Sheps

Fairygirl

No - the finer stuff @debs64. You can buy it in B&Q rather than the more expensive stuff in GCs. I put mine into a container with holes in the base, and then all the muck gets washed through 

They love Heucheras, but it's ones in pots they love - captive audience. 
I occasionally just tug the ones I have potted, which isn't many. If they lift, you know those little grubs are busy. I then wash, or pick,  them off, leave them for the birds, and re pot the remaining plant once I'm sure there's none left on it. They'll sprout from virtually nothing, and it's easy to split them by just pulling bits off and potting them up. 
I still have adult damage on various bits of foliage, but that's just aesthetics and isn't a problem on otherwise healthy plants.
I don't really get any other potted plants troubled by them, but the grit is also ideal for dressing pots - I know you have loads. Any gravel is fine for that though   

SherwoodArrow

bédé said:  And aren't nematodes expensive?

I find lots of people say/ask this when I talk about using them and always comment that I must be rich. Amazon have the nemasys ones on between £10 and £11 for the 12sqm pack. I’m very happy with this price and haven’t lost a plant since using them. 

debs64

Yes @SherwoodArrow I only want enough for a few pots should cost me around £10 I think it’s money well spent to save my plants and I will try the pea shingle too. 

As @Fairygirl said I have lots of pots but most are not too affected with vine weevils. Heuchera seem particularly vulnerable. 

Sheps

@debs64 pea shingle will be too big, you need Horticultural Grit or the like.

And make sure it's a good deep layer, mine is about an inch or two deep.

debs64

@Sheps horticultural grit it is 

JessicaS

Ive used them to get rid of the nasty little devils as I cant easily grit my planters and found them very effective, they got rid of the lot! Once its a bit warmer I will be ordering more.