Your Best Friend in the Garden – Bacteria? by Don
When we think of bacteria,
we usually think of hospitals and infections and using anti-biotics to stop
them. On the other hand, good bacteria in our gut helps us to digest food and
fights off bad bacteria. We don’t think twice about eating some nice tasty
yogurt loaded with billions of bacteria cultures because they are supposed to be
good for us.
There are plenty of
bacterial diseases that kill or injure plants. There are sprays and drenches to
fight them. Thankfully in nature, we have a lot of good guys fighting back and
they are pretty effective against things that attack plants – including insects.
Since the 1950’s, we’ve had
BT or Bacillus thuringiensis, a soil bacterium, that is effective only against
moths and butterflies and their voracious caterpillars. This is important
because it doesn’t harm beneficial insects or mammals and because it is organic,
BT has been used by organic farmers around the world with no problems of
resistance by insects. Every garden store carries it.
Recently, BT toxin has been
genetically engineered by Monsanto and inserted into corn, cotton and soybeans.
This toxin is persistent in the plant for a long time unlike the bacterium,
which breaks down rapidly under sunlight and the elements. Like most overused
chemicals, insects are becoming resistant to BT especially when the BT crops are
planted year after year. This takes a great tool away from the organic growers.
There is also a question of what effect the toxins in the corn may have on
animals and people.
There are other BT strains
that are specific against other insects like beetles and mosquitos. There are
mosquitos dunks that can be tossed in ponds or even horse troughs that will not
harm fish or animals.
In 1985, Saccharopolyspora spinosa, also known as Spinosad, was a bacteria
discovered by chance in a vat in a sugar rum mill in the Virgin Islands. It
turned out to be an excellent insecticide on many insects and mites but not on
aphids. It also is not toxic to animals. Captain Jack’s Deadbug is one available
spray that says “for organic gardens” but is not actually registered OMRI
Review Institute). That would be important if you needed to use registered
organic materials. Monterey’s Garden Insect Spray with Spinosad is registered.
There are many formulations of Spinosad including hose end sprays, ready-to-use
also used in Sluggo Plus with the Sluggo part killing slugs and snails and the
Plus part killing earwigs, sow bugs, crickets and ants. Now you can kill those
insects and snails without worrying about harming your pets since Sluggo
contains Iron phosphate instead of Metaldehyde.
down side of Spinosad is that it is toxic to bees. Be sure not to use it when
you have flowers that bees might visit. If you have fruit trees, let the fruit
set and then spray.
also a product on the market called Serenade, which
contains Bacillus subtilis, a soil-dwelling bacterium, that controls diseases
like leaf spot, mildew, rust, black spot, fire blight and other diseases. It
works well on tomato blight too but does not harm insects or animals. Serenade
is being used commercially as well as by home owners and is OMRI certified. It
can actually be used on the day of harvest. Serenade is available in a
ready-to-use bottle or a concentrate.
really can let nature help us in the garden using billions of bacteria to fight
our battles. Instead of being the helpless gardener, you can be the mighty
general, directing your minions by spraying them on your plants to defeat
insects and disease. You might want to keep the sound effects down in case your
neighbor is watching however. He might not understand either why you are
spraying bacteria all over your yard. Just tell him it’s a war out there and you