BCSS - Forum

Hi all, many years ago pest control was a spray/drench with one of the many available controls at the time. 3 times a season as a preventative. Now with nearly all the good stuff unavailable (health and safety ) ? and what is available is quite expensive how do growers go about this task? Do we still spray as a preventative, or wait until some damage occurs, than spray ? Thanks.

I don't see the point in preventative spraying for pests. For fungi yes, such as with potato blight or black spot where you know that plants will be infected. But what are you spraying for if no pests are present? You just kill beneficial insects and arthropods and give the pests a free run if they appear. I don't spray unless I see a pest, with the exception of all new acquisitions which get a bare root dip in insecticide and a quarantine period.

I do not trust myself to spot the early stages of a pest infestation in my large collection, so I still use pesticides on my plants on a regular basis. With succulent plants, we cannot tolerate any pest damage or the plant might well be ruined for ever. As far as I can tell from browsing the garden centres, we only have three controls available to us at the present time:

Deltamethrin (a synthetic pyrethroid) which should kill most insects (not mites) within a few hours;

Acetamiprid (a neonicotinoid) which it is claimed will kill red spider mite as well as other insects (does it work on red spider; any experience?);

Surfactants/oils which kill pests by physical action, e.g. SB plant invigorator (N.B. neem oil might have a chemical as well as a physical affect).

Quite a limited range really and I find it much more difficult to control pests now than I did 20 or 30 years ago. Unfortunately the branded pesticides, e.g. Bug Clear and Provado, keep changing the active ingredients and one really needs to look closely at the small print to see what chemical they contain.

I quite agree Terry, it is all much more difficult than it used to be. Here in Great Bookham, not very far from you, I have problems with vine weevil, which destroys Echeverias and similar before you even know it's there. For years I have used Provado Vine Weevil killer twice a year, and it was very effective, I think it helped to keep MB at bay also. Now it is no longer available and I haven't yet found an alternative. For red spider I find SB plant invigoration quite effective, but of course it has to be used regularly. Sometimes it all seems like a constant battle!

juster wrote:For years I have used Provado Vine Weevil killer twice a year, and it was very effective, I think it helped to keep MB at bay also. Now it is no longer available and I haven't yet found an alternative.

I went looking round local garden centres for Provado VW Killer a couple of weeks ago, couldn't find it but found this instead. Can't check right now but online info says it contains Acetamiprid.

I've used it once, but only, recently so I can't vouch for its effectiveness yet but I did prefer that it's a clear liquid. The milky Provado VW killer always made me feel like I was pouring yoghurt over my plants.

All Provado products containing Thiacloprid have been discontinued. I think Bayer just can't be bothered with the hassle any more. Some Provado products will be reformulated with Deltamethrin, which is not systemic. Not the Vine Weevil Killer obviously, don't know what they're going to do there.

I was looking into Nematodes for pest control, at the Tatton Show yesterday. It seems they are available for vine weevil. I thought it had to be used in a greenhouse or enclosed space but the guy there was emphatic that it was for use outside, particularly in pots. I have been seriously considering using nematodes, as I am really fed up with finding vine weevil grubs in the compost of sick-looking plants, especially Sedums and Echeverias. the main obstacle to use is the cost, which you have to weigh up against the cost of new plants.

I have used nematodes against vine weevil outside in the garden (not in pots) in the past with some success.The problem is they are expensive and you have to make up a batch which then has to be used straight away and they only have a short shelf life so you can't keep some 'just in case'.
I have sent for some neem oil and see if that helps.It does smell a bit but I thought I would treat my plants outside and wait for the pong to pass! I don't have too many plants so could be a solution for me.

I use neem oil and have found it very useful against mealy-bug. I put 10ml of neem oil, 10ml washing-up liquid into a 500ml spray bottle, top it up with water and give it a good shake before I use it. It does mark succulent leaves but is worth spraying under the plant and on the top of the compost, once all leaf debris and visible mealy-bugs have been removed. It does not seem to mark cacti. I have used it with some success against RSM but it has to be sprayed regularly( once a week) to be effective.

w-u-l alone at that strength (and much less) should do for mites.