Can I trust b.t. spray?

paradajky · June 21, 2022

Can I trust b.t. to do its job while I'm gone for about a week?

I've removed over 20 baby hornworms and dozens of eggs off my small 10 plants since the weekend. Leaving this afternoon. I sprayed with monterey b.t. last night.

There were six more baby hornworms this morning.

It would not be fun returning to my little crop gone that I'm struggling with already. Debating asking the neighbor to check them out, but concerned about liability. I have family that could swing by, although they are elderly and access requires going down stairs without a hand rail. The guilt if they hurt themselves are not worth the potential prevention.

Anything else I can do, or is this one of those just hope it'll work out, and if not, laugh it off and try again next year?

Thank you for your time!

PaulF · June 21, 2022

BT will kill hornworms and effectively and safely for everything but worms. Be aware that the life of the BT is effective between one and four days so the last three days of your absence if you have another infestation there may be hornworms eating leaves. I bet a good dosage will kill everything you have.

paradajky · June 21, 2022

I was not aware its life was only 1-4 days. The instructions say to spray weekly.

I appreciate the information, got it and understood, thank you!

JRinPA · June 21, 2022

I've been doing approx weekly for cole crops this year. I use the BT at spec (1 tbsp per gal for mine) so for a 1/2 gal hf sprayer it is a big teaspoon + a drop of dish soap + dribble ~1/2 tsp of molasses. It has been working really well, no worms at all on anything as yet.

I have yet to try it on tomatoes, not too many hornworms here. I'd definitely trust it for a week on cole crops.

b54red · June 24, 2022

I use a wettable powder that is very concentrated and add some Dawn or wetting solution to the mix and spray my whole garden with it several times a season. I used to just apply bt to problem areas but found that I was having to mix it up and spray more often. So far this year I have only had a few foliage worms, a couple of pickle worms and two tomato fruit worms. I try to spray about every three weeks or so and it has reduced the usual damage from worms tremendously this year. I wish I knew a way to deal with spider mites as easily because I know they will be here soon with the extreme heat and dry weather we have been having.

This is a link to the product I use and it stores for a long time and a little goes a long way.
https://www.domyown.com/dipel-pro-df...de-p-2361.html

Bill

paradajky · June 28, 2022

I'm back now a week later - family was kind enough to spray again at day 3, and I arrived home to a jungle of tomato plants, with no hornworms, yay!!

b54red: thank you for the powdered B.T. link!! I have liquid concentrate for this year, which has a shelf life of only a year. The powder form lasts 3 years according to the literature, and is only a few bucks more expensive than the liquid concentrate, so I will get some next year.

June 21, 2022	#1
paradajky Tomatovillian™ Join Date: May 2021 Location: Coastal Southern CA Posts: 164	Can I trust b.t. spray? Can I trust b.t. to do its job while I'm gone for about a week? I've removed over 20 baby hornworms and dozens of eggs off my small 10 plants since the weekend. Leaving this afternoon. I sprayed with monterey b.t. last night. There were six more baby hornworms this morning. It would not be fun returning to my little crop gone that I'm struggling with already. Debating asking the neighbor to check them out, but concerned about liability. I have family that could swing by, although they are elderly and access requires going down stairs without a hand rail. The guilt if they hurt themselves are not worth the potential prevention. Anything else I can do, or is this one of those just hope it'll work out, and if not, laugh it off and try again next year? Thank you for your time!

June 21, 2022	#2
PaulF Tomatovillian™ Join Date: Jan 2006 Location: Brownville, Ne Posts: 3,294	BT will kill hornworms and effectively and safely for everything but worms. Be aware that the life of the BT is effective between one and four days so the last three days of your absence if you have another infestation there may be hornworms eating leaves. I bet a good dosage will kill everything you have. __________________ there's two things money can't buy; true love and home grown tomatoes.

June 21, 2022	#4
JRinPA Tomatovillian™ Join Date: Jul 2013 Location: SE PA Posts: 972	I've been doing approx weekly for cole crops this year. I use the BT at spec (1 tbsp per gal for mine) so for a 1/2 gal hf sprayer it is a big teaspoon + a drop of dish soap + dribble ~1/2 tsp of molasses. It has been working really well, no worms at all on anything as yet. I have yet to try it on tomatoes, not too many hornworms here. I'd definitely trust it for a week on cole crops.

June 24, 2022	#5
b54red Tomatovillian™ Join Date: Sep 2009 Location: Alabama Posts: 7,068	I use a wettable powder that is very concentrated and add some Dawn or wetting solution to the mix and spray my whole garden with it several times a season. I used to just apply bt to problem areas but found that I was having to mix it up and spray more often. So far this year I have only had a few foliage worms, a couple of pickle worms and two tomato fruit worms. I try to spray about every three weeks or so and it has reduced the usual damage from worms tremendously this year. I wish I knew a way to deal with spider mites as easily because I know they will be here soon with the extreme heat and dry weather we have been having. This is a link to the product I use and it stores for a long time and a little goes a long way. https://www.domyown.com/dipel-pro-df...de-p-2361.html Bill

June 28, 2022	#6
paradajky Tomatovillian™ Join Date: May 2021 Location: Coastal Southern CA Posts: 164	I'm back now a week later - family was kind enough to spray again at day 3, and I arrived home to a jungle of tomato plants, with no hornworms, yay!! b54red: thank you for the powdered B.T. link!! I have liquid concentrate for this year, which has a shelf life of only a year. The powder form lasts 3 years according to the literature, and is only a few bucks more expensive than the liquid concentrate, so I will get some next year.