Planning on doing the first water of the year I've decided to add some Vine Weevil Killer into the mix. Looking at the bottle it says 60ml per litre of water.....
So if I am using a TWO gallon bucket that means I've got to put 600ml of chemical in - or more than a bottle. That can't be right surely? At that rate I'd need nine or ten bottles to do the whole greenhouse.
ETA- using TWO gallon bucket and not a ONE gallon bucket as said at first.....
Last edited by Chris L on Sat Mar 23, 2019 10:56 am, edited 3 times in total.
You haven't said Chris what type/brand of vine weevil killer you are using. If you are using a nematode-based one, then the nematodes might get filtered out as the water rises to the surface by capillary action. It is possible that there could be no nematodes at the top of the pot where the weevils are most likely to be in the stems of your plants - I assume that you are treating echeverias, which are the most susceptible succulents?
I've used this for a few years, since Provado stopped being effective for vine weevil, it does suggest a much higher concentration that the normal Bug Clear Ultra, which is not effective for vine weevil. I quite agree that it's pretty expensive! I just water it in from the top with a watering can and I certainly don't splash it about! Maybe it's a case of thinking about which plants you are treating and how much trouble you have had with VW. I have had more Echeverias devastated by this pest than I care to remember, therefore, for me, it's worthwhile, but I no longer treat all my cacti.
Incidentally I've an idea that it's best not to use insecticides on the first watering of the year, more effective on the second or third. Perhaps someone knows for sure?
Croydon Branch member, growing mainly cacti and Echeverias
I use it every year too, yes, it's very expensive and I need to buy about 10 bottles for my needs. As Juster says, water each pot individually, you don't want to waste any! I also use it selectively, mainly for mealy bug control (although I don't know how effective it actually is for MB), so I don't use it on Haworthias, which rarely seem bothered by MB, but all cacti and crassulas and echeverias.
I'm about to get some today, as my local garden centre sells it for £6.99 a bottle, which is the cheapest I've seen it.
I also wait until I've done one or two watering a before I use it.
Nobody has yet said what vine weevil killer they are using! If it is Bug Clear Ultra then this seems to be the last surviving amateur product that contains a neonicotinoid systemic pesticide (Acetamiprid). As such, for the systemic action to occur, the plant does need to be growing and absorbing moisture from the compost. Therefore using it in the first watering of the season would not be a good idea for getting to mealies, etc, although the contact effect on weevil larvae would still be OK.
If using a nematode product such as Nemasys, then the action is by contact only and using it now would be great, particularly since the weevil larvae are nice and plump and active in the soil at this time.
Using nematodes probably requires that you have not used chemical pesticides on the plants for some time.
So am I better getting a bigger, deeper, tray filling nearly to brim and dunking pots right up to the rim. It would be too fiddly to water each pot on its own.
. I only usually put a half a capful in a bucket. 
