Yeah with only 4 plants you could easily get by with one of those 1 quart plastic spray bottles. But you will have to spray more than once so you could mix up a gallon.

You don't mention what brand name of Thuricide your bought. Bonide's brand is 1-4 tsp per gallon of water. High-Yield brand is 1.5 oz. per 3 gallons. Southern AG's is 2-4 tsp. per gallon. So they are all different concentrations and some flexibility is allowed.

Dave

You'll spray them once a week. The concentrate has a shelf life (cool conditions) of a few years. Plant more broccoli! Spraying method? For just a couple of plants, a small 32oz hand sprayer is all you need. Wet all leaves and stems. I guess you can dance happily when you do so ...

My instructions on the Bonide Thuricide say "Do not store diluted spray mix for more than 12 hours". So if you follow those directions, do not mix up a big batch to use leftovers later. Only mix what you need to spray at one time.

The problem I have had with thuricide and broccoli is it tends to roll off the leaves. You want a fine mist to spray.

That's interesting about storage of diluted solution. My Southern Ag Thruricide gives you 24 hour of storage time. All the more reason to mix it in small spay bottles.

Wow - you guys are amazing! Thank you so much for the quick responses. I went ahead and mixed up a small batch, sprayed it on using a plastic bottle with a mister. Soaked the plants until they were dripping, both sides of the leaves and just tossed the rest. I didn't see any new worms, so I was happy about that. I'll respray again next week. It's going to be hot and dry this week.

Thanks again!

I would not mix more than you would use at one time. A couple years ago I accidently left some mixed BT in my sprayer in my cool basement overnight and the next day when I opened the sprayer to dump it, it stunk to high heaven!!!! I don't measure how much I put in my 40 oz. spray bottle but I would guess about 1 tsp.

Peter - use a few drops of dish soap as a surfactant and it should stick to the leaves better or buy a bottle of Sticker Spreader. My last bottle lasted at least 10 years.

I too have used surfactants to improve the "stickiness" of insecticides. But we should be careful. It has been shown that some egg-laying insect pests actually prefer foliage that has been treated with surfactant. Not entirely clear either how BT is affected by mixing with such surfactant. That is, if the surfactant makes the BT cling to the foliage better, that's nice, but not if it degrades the BT.

Interesting Dan...I had never though about the surfactant degrading the BT or actually attracting more moths but I always use it when I spray BT and the BT does what it is paid to do so in this case I don't believe it has a negative affect. I rarely ever spray any other insecticides so I don't know how surfactant might affect others.

Well, thanks, that's important to know, that after combining with surfactants, BT continues to work well. We just have to be a little careful here because we're not dealing with chemicals, but with live creatures. I'd have no hesitation about mixing dish soap with copper fungicide!