The Urban Farmer, Issue #043 * Hydrogen Peroxide * Controlling Aphids
“After all, Eden was garden… the garden is a
place to go for quiet contemplation, a source not only of food but also of
spiritual renewal and intimate contact with life’s most basic processes.”
~ Ed Smith,
The Vegetable Gardener’s Bible
Hydrogen Peroxide: Cheap and Versatile
Hydrogen Peroxide (H2O2) is a water molecule with an extra atom of Oxygen
attached. This extra Oxygen atom is quite easily detached from the water
molecule and eagerly combines with any suitable substance that has the room for
it. For example it will attack organic blood cells.
Any drugstore offers 3% hydrogen peroxide solution for human use. This liquid
is good for treating minor cuts and scrapes etc. It is also used for softening
ear wax. It works by oxidising the chemical parts that are presenting as having
a free space for the Oxygen atom.
When (H2O2) comes in contact with these “impurities” it
will give a reaction which causes it to fizz. This fizzing is the Oxygen atoms
coming out of their bond with the water molecules and bubbling out of the
solution. As gardeners, we can use this eagerness to break its bond to help keep
our plants free from everyday pests, and our nutrient solutions free of
anaerobic (bad) bacteria.
In the same way as old organic blood cells are attacked and consumed by the
fizzing action of the peroxide, so will any bacteria and small insects be
destroyed by a 3% solution. At this strength it is safe for human skin but
lethal to most bugs.
Mix up the following for a weekly preventative spray:
In a clean quart empty spray bottle:
* 1/4 cup of 3% Hydrogen Peroxide
* 2 tblsp. of rubbing Alcohol (or Old style mouth wash like Listerine)
* 1/4 tsp. of wetting agent (Dishwashing liquid will do)
Use this mixture as a foliar spray to keep your plants healthy and free from
Another advantage of the Peroxide breaking down is that it releases free
Oxygen into the area. So, if you were to add some to your nutrient tank, the
dissolved Oxygen being released around the root system not only kills any bad
root material and bacteria, but also oxygenates the roots with the excess Oxygen
produced. To treat your nutrient vat, add a couple of tablespoons to 1/4 cup 3%
peroxide to the vat weekly.
Plants can easily cope with a 3% H2O2 solution and because the mixture
reduces to water in a short space of time, the dilutions are not that critical.
For this reason, it also makes a great disinfectant for plant pots, greenhouses,
A really great advantage is that you do not have to rinse it away after
use because it will revert to water on its own.
Plants may look wilted and sickly, and fail to thrive. Leaves may be yellowing.
Aphids suck the plant sap in the leaves and can kill the entire plant.
Look closely, and you will find dense colonies of tiny, soft-bodied bugs,
usually yellowish. They often collect on the undersides of leaves or the growing
tips of the plants. You will also find a sticky honeydew trail they exude, which
attracts ants. If you’ve got ants, look for aphids.
TREATING LIGHT INFESTATION
Pick the squishy little (1/32-1/8 inch) aphids off by hand and crush them.
Green Lacewings, gall midges are all good insects which prey on aphids.
Spray repeatedly with
Hydro Tip of the Month- Stay on Top!
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We hope you have enjoyed this issue of The Urban Farmer Ezine. Each month, we will bring you another inspiring photo, gardening quote or idea, plus fresh new hydroponics news, techniques & products.
Insiders tips to get you growing…
~Stella and Simon from