Merit 75 as a Drench

[DebsC]

Big guns time. I'm sick and tired of scale showing up over and over on some plants. It's time to get rid of the little buggers!

I grow in lava rock mixed with charcoal.

Is pouring Merit through the medium one time going to be enough or do you put the pot in a bucket or other container and pour the mixture through again?

How much mixture do you pour on each pot?

This process is repeated how often?

Anybody know of any orchids that are sensitive to Merit? Like, it might damage them?

Any info and help is much appreciated!

[camille1585]

I think Merit is imidacloprid, right? I use Admire, which is a different brand name for the same active ingredient.(but I don't know if the concentration is the same.) I used it as a drench on my orchids, following the instructions on the box (ex, for a 14cm pot, I had to add 1,5ml product for 100ml water). On the box it is also written that it takes 1-3 weeks to have full effects. I think it works at least a month or two. Then re-treat (preferably with a different product) if you see more bugs.

Someone I worked with in a garden center told me to avoid using it on plants in bloom. In you spray it, it is 100% certain the blooms will be affected. As a drench he was not sure, but to be on the safe side I didn't treat any plants in bloom. I don't know if any orchids are overly sensitive to it or not.

[mojomick]

I use Bayer Advanced 3 in1. I drench and spray. It seemed to work for me.

[DebsC]

Thanks guys for your answers. I've used the Advanced 3 in 1 before. It seems to do the job but then the mealies and scale come back...stronger!

So this time I'm going to use the full strength imidacloprid product. I have 150-175 orchids and I want these creepy crawlers out of my greenhouse!

[orchids3]

I have used Bayer Tree and Shrub - which in the past was a diluted imidacloprid - I see that something else has been added this year. It works well - but you need to rotate your pesticides or the bugs will get imune to whatever you use.