Author Topic: How long does BT last?  (Read 2946 times)

EarthBoxAdmin

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How long does BT last?
« on: June 20, 2017, 09:59:04 am »
Disclaimer: This post was originally posted by Jr. Member, DonAndRene. This user is located in McKinney, TX; Zone 8a. This was originally posted on May 4, 2014.

I mixed up some BT last season in a sprayer. Should I toss out that batch and make a new one for this season?

I have not found anything talking about if BT loses it's effectiveness over time.

Thanks!

EarthBoxAdmin

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Re: How long does BT last?
« Reply #1 on: June 20, 2017, 10:00:08 am »
Disclaimer: This post was originally posted by Hero Member, mjb8743. This user is located in Zone 7, South NJ, Garden State. This was originally posted on May 4, 2014.

Once BT is mixed ready to use, any left over should be dumped. Even when applied, it's effectiveness is only a couple of days. It breaks down quickly, especially in the sun.

A better product is one that contains spinosad. It will kill the caterpillars same as BT, but lasts about 14 days, and is a good insecticide as well.  The only caveat: it will kill bees if applied during the time when bees are active. Once dry, it's perfectly safe. Check out Captain Jack's Dead Bug Brew or Monterrey Garden Spray.

Any product should be discarded once it's been mixed ready to use.

Mickie

EarthBoxAdmin

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Re: How long does BT last?
« Reply #2 on: June 20, 2017, 10:03:32 am »
Disclaimer: This post was originally posted by Horticulturalist The EarthBox Hero Member, kathy. This user is located in the mountains of PA Zone 5, almost 4. This was originally posted on May 5, 2014.

Mickie is 100% correct, and any leftovers , should be discarded. When you use a RTU (ready to use) spray, the mfg has been in stabilizers to allow the ingredients to stay pre-mixed and stable. The concentrates do not have these stabilizers in them. That's why I have a one gallon sprayer, just for my EarthBoxes.

EarthBoxAdmin

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Re: How long does BT last?
« Reply #3 on: June 20, 2017, 11:22:01 am »
Disclaimer: This post was originally posted by Jr. Member, DonAndRene. This user is located in McKinney, TX; Zone 8a. This was originally posted on May 5, 2014.

Thanks for the responses. Sounds like I need to go the a ready to use mix. I do have a 1 gallon sprayer, but a gallon is overkill for 2 EBs of squash.

Thanks!

EarthBoxAdmin

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Re: How long does BT last?
« Reply #4 on: June 20, 2017, 11:23:29 am »
Disclaimer: This post was originally posted by Full Member, LinFL. This user is located in Zone 8b/9a border, NW FL. This was originally posted on May 5, 2014.

The RTU sprays tend to be very expensive per use. By all means avoid any sprays in bottles with hose-end connectors, since every one of those I have ever seen seems designed to waste as much product as possible. Grrr!

Since you only have two boxes, you could get a spray bottle (usually a dollar or less at a big box store or a dollar store). You can mix up your concentrate in that. You just have to measure the capacity of the spray bottle (if it's not marked) and do the math one time to figure out how to properly dilute the concentrate. Actually, I'd get a quart spray bottle and mix up only a half-bottle at a time to start off with. Once your squash get big and bushy you might be surprised at how much spray it takes to get good coverage on the top and bottom of each leaf. A little bitty spray bottle might not be enough.

The downside of using a spray bottle is that you have to squeeze repeatedly to dispense the spray. That can be hard for folks with arthritis or other hand problems.

Also, just because you have a one-gallon sprayer doesn't mean you have to fill it each time. If your sprayer does a good job of using up all the spray, you can make up just a fraction of a gallon each time.

EarthBoxAdmin

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Re: How long does BT last?
« Reply #5 on: June 20, 2017, 11:24:49 am »
Disclaimer: This post was originally posted by Jr. Member, rsqwyr. This user is located in Austin, TX Zone 8b. This was originally posted on May 5, 2014.

What is the best way to dispose of left over spray?

Julie