How young of a plant can I spray BT on?

[Hammerhead]

First wave of plants have been in the ground for about 3 weeks now.  They're from about 3''-6'' in height now. Gonna start them on the same fert regime that I used last year starting this week. I am noticing some leaf tear/ possible chewing signs and was wondering if it was safe to give a spray of BT at this time, or do you think the plants are too young? No physical/actual proof of bugs, but maybe a pre-emptive strike will make me feel better. Thanks in advance,Pat

 

[mikeg]

BT is a live bacteria known as "Bacillus thuringensis"... a breed of this microbe, commonly called "BTK" (Bacillus thuringensis kurstakii) is specifically used as a biological warfare weapon against moth and butterfly larvae.

Check plants that are showing damage. Look until you find actual live caterpillars, then spray BTK to effect control/eradication.

It won't work against other insects. It won't work against pests other than insects. It won't even kill a caterpillar unless they eat some of the bacteria. (Hint: Spray leaf undersides so rain/sun/etc. don't remove/kill bacteria before they get eaten).

There is a similar bacterium, "BTI" (Bacillus thuringensis israelensis), which kills fly larvae -- the fly family includes mosquitoes, gnats, etc.... this bacteria will not affect caterpillars, but it is the bacteria found in 'mosquito dunks', and the reason why mosquito dunks are used to control fungus gnats.

Note that the water you mix with BT sprays and dunks must be dechlorinated or the chlorine will kill the bacteria you are trying to infect the pests with.

EDIT: Uhhhh... i forgot to answer your question: the plants can be any age, and tolerate BTK sprayed on the leaves, or BTI poured over their roots. It's one of the least harmful pest controls (well, for the plant...) available.

 

[moruga welder]

BT is a live bacteria known as "Bacillus thuringensis"... a breed of this microbe, commonly called "BTK" (Bacillus thuringensis kurstakii) is specifically used as a biological warfare weapon against moth and butterfly larvae.

Check plants that are showing damage. Look until you find actual live caterpillars, then spray BTK to effect control/eradication.

It won't work against other insects. It won't work against pests other than insects. It won't even kill a caterpillar unless they eat some of the bacteria. (Hint: Spray leaf undersides so rain/sun/etc. don't remove/kill bacteria before they get eaten).

There is a similar bacterium, "BTI" (Bacillus thuringensis israelensis), which kills fly larvae -- the fly family includes mosquitoes, gnats, etc.... this bacteria will not affect caterpillars, but it is the bacteria found in 'mosquito dunks', and the reason why mosquito dunks are used to control fungus gnats.

Note that the water you mix with BT sprays and dunks must be dechlorinated or the chlorine will kill the bacteria you are trying to infect the pests with.

  ( hint : spray underside of leaves . shhh don't tell those damn caterpillars !   i like it my friend , sneaky !