It is funny the way that works. I just sprayed mine last night and was thinking the same thing. In years past, when I have sprayed, I just made repeated applications. Despite it looking like it rolled off, enough stuck to get some control.

Do you have worms now? It is better to be preventative with your Bt spray than to be reactive.

Jay

I always think the same thing too! It seems to just roll off my cabbage and broccoli. But I have found that it's working.

It is sticking. You just can't see it and if you could then it would be so thick it would interfere with photosynthesis. But it works just as soon as they nibble on the leaf.

Dave

wow, I didn't even know there was a spray. I always use powder, which I find messy. Does the spray work better?

Mine is Safer brand and it comes in a concentrate labeled "caterpillar killer" or something like that. I like it because I keep it mixed in a gallon pump sprayer so it's really easy to apply.

But does the stuff have to smell like rotting flesh? That's my only complaint. Not that I know what rotting flesh smells like, mind you. I'm just trying to imagine something that would be as putrid as my Bt spray.

Safer brand caterpillar killer uses Dipel (Bacillus thuringiensis var. kurstaki), which is available in powdered form from Johnny's. Is that the same powder you use, Michele?

I've been using the powdered version, mixed with oil, for corn, not broccoli. It smells "biological," but not terrible.

Use a drop of weak dishwashing soap in the spray bottle. They also make a sticker additive.

Better still, use Compost tea. I'm not sure I would like to eat "Bacillus thuringiensis" in spite of what they say.

I have no problem with Bt not working on cabbage and broccoli without stickers.

Dan

To me, the liquid Bt smells like pee and Serenade smells like vomit. I prefer the smell of Bt by a narrow margin.

Yes, I do use a powdered form called Dipel, which I purchased at my local nursery. It has no smell, and I just sprinkle it on with my hands. It doesn't smell, so now I'm re-thinking my interest in the spray :) The powder does it's job but I thought I'd rather now have to grab a handful of it if I had a spray bottle, I guess I'll stick with the powder. It was about $5 for a big bag that has lasted me 3 yrs so far.

Thanks for all the responses. I feel a lot better about the effort I put out to mix and apply spray. I didn't know there was a powder. It may be less of a hassle to apply if I can find a shaker with right size holes. Mixing and spraying is exhausting. The powder is definitely cheaper and I might be less inclined to procrastinate getting the job done. Can you see it sticking on the leaves?

Yes, it does stick on the leaves just fine, but you do have to re-apply after rain and maybe in the fall every few days if there is a lot of dew. If you have a lot of plants to cover, I think there is some sort of applicator you can buy. I think a friend bought one last year on amazon, but I didn't see it.

The only thing I wonder about with the powder is how you get it under the leaves? That's where the caterpillars hang out. I guess enough just "blows around" to get up underneath? I have a relatively small garden, so mixing the liquid in a 2 gallon pump sprayer gives me enough to last the whole year. In fact, I've got a row of 2 gallon sprayers I keep in my shed, one with neem, one with copper fungicide, one with Bt. They're all very grab-n-go which is just the way I need it. If bug control requires any effort on my part, I'm too quick to go, "Eh, I'll get to that next weekend." :-D

I agree about getting underneath, but I figure if they take a bite out of the leaf, they get the bt powder whether it's on the top or on the bottom :)

Yes, there is no need to spray under the leaves. They chew through and get the BT just the same. If it were leaf miners it would be another matter. I see no one has mentioned it, but let me add that if your BT spray is beading, you are spraying too much.

For some reason, I thought that all these various sprays could not be stored--another garden delusion? If they can be stored, that would take care of most of my resistance. Is there any spray that cannot be stored?

My bottle of liquid concentrate says it only stores for 12 hours once mixed with water.

Machy--thanks for the specifics on storage. One of my winter projects will be to make a chart for the sprays/remedies that I use that will tell me mix ratios, conditions of application, harmfulness to bees, target populations, storage, etc. This will minimize the "work" and time it takes every time I have a problem to solve.

2B, MOST mixes cannot be stored. As a general rule, you shouldn't mix any more than what you know you will use right away. It's pretty easy to cut mixing directions in half or less, if needed.

I honestly don't know about Bt, but I still wouldn't break that simple rule.

I really, really like your plan to make a chart. Be sure to let me know if I can help!

Behlgarden--thanks for reminding me that poders are tricky and you risk inhaling the stuff more so than with liquids. I used kaolin this summer and it was tricky scooping it out to mix with water.

Rhizo--This past year, I used a single sheet for each product including fish emulsion and kelp to write out dilution rates so that I could quickly mix 1 gallon to 1 cup of solution. I found that increased the chances that I would actually mobilize and get the job done knowing I would not have to read the directions again(with a magnifying glass) and do the math--again. That stuff can wear me out. I need to add all the other stuff including things like don't apply pyola when temperatures are over 90 degrees. I AM clear, now, on not storing stuff. Thanks to all.

Set your spray to the finest mist you csn get. The drdroplets are so small they don't roll off, don't over do it or they will pool and roll off , just a light