essential oils
Another study noted essential oils
extracted from different chemotypes
of garden thyme did not have similar
toxicity against the bean weevil. These
variations can cause problems for the
commercial production of essential
oil-based pesticides, especially for
smaller businesses that do not have
the funds to manufacture a consistent
product themselves.
Although essential oils are produced
in large quantities for the food and
cosmetic industries, large-scale
commercial production would require a
substantial increase in the production
of certain oils. This can be quite costly,
as it can take thousands of pounds of
plant matter to produce just one pound
of essential oil.
On a large scale, this may not be cost
effective when you consider essential
oil-based pesticides require frequent
application rates and a high concen-
tration of the oils in the pesticides (as
high as one per cent active ingredient).
Although not as safe, synthetic pesti-
cides are less expensive and more
effective in the short term.
MUST-HAVE ESSENTIAL OILS FOR
YOUR GARDEN
For your home garden, however, it
is easy to make your own essential
oil pesticides and fungicides to treat
common pests and diseases. Most
essential oils have a negative effect on
pests, and the following oils stand out in
the garden and are backed by plenty of
science to support their effectiveness.
Peppermint
Peppermint is arguably one of the
best essential oils you can add to your
gardening routine. It works well against
ants, aphids, beetles, caterpillars, flies,
gnats, mosquitoes, moths, and even
spiders. If you store any grains, use
peppermint-soaked cotton balls nearby
to deter beetles from getting into your
supply. Peppermint also has fungi-
cidal properties and works well when
sprayed on plants with fungal issues.
80
grow cycle
“ Studies have shown
sandalwood oil is effective in treating the twospotted
spider mite and reduced the total number of eggs found
on the infested plant’s leaves by 89.3 per cent.”
Sandalwood
If your plants are facing environmental
stress, spray them with a sandalwood
solution. The terpene called santalol acts
as a strengthening agent for plants and
makes them hardier.
Studies have also shown sandalwood
oil is effective in treating the twospotted
spider mite and reduced the total number
of eggs found on the infested plant’s
leaves by 89.3 per cent.
Tea Tree
Tea tree has strong antifungal properties.
Studies have shown tea tree oil effectively
fights the fungi that causes Fusarium
head blight in wheat, barley, and oats. It
has also been proven to treat barley, leaf
stripe, powdery mildew, anthracnose, and
leather rot in strawberries, early blight
disease in tomato plants, Cercospora
beticola on sugar beets, and Alternaria
solani on potatoes. It also repels whiteflies.
To create your own tea tree fungicide
spray, mix two tablespoons of tea tree
oil with two cups of water and spray
plants every three to seven days. Tea
tree oil is sensitive to phototoxicity, so
spray in the morning when the sun is
not shining as brightly.
Orange
Orange oil will treat ants, aphids, beetles,
caterpillars, chiggers, cutworms, fleas,
flies, gnats, mosquitoes, moths, roaches,
snails, slugs, spiders, and ticks. The
terpene called d-limonene is the main
constituent of orange oil. It will not harm
humans, but it will kill insects by dissolv-
ing their exoskeleton, which dehydrates
and suffocates them. Many claim one
application of an orange oil solution is
all it takes to wipe out an entire colony
of pests and prevent reinfestation. Ants
are especially susceptible to orange oil
because the oil destroys their pheromone
trail so that new ants will not take their
place. It is important to be aware this oil
will also harm beneficial insects, so be
careful where you spray.