Q. Do you prefer Neem oil or
Horticultural oil when spraying fruit trees?
A. Horticultural oil isused for spraying trees and shrubs when leaves are absent during the winter. Horticultural
oils, sometimes called dormant oil or even dormant spray, have a very specific
viscosity or “thickness” which makes them effective in killing pests. These oils
are petroleum-based and refined so they don’t damage plants if applied
correctly.
When spraying trees, fruit trees and shrubs make sure the
entire plant is covered with horticultural oil from “head to foot”. Neem oil is
used primarily during the growing season when leaves and the offending insects are
present.
entire plant is covered with horticultural oil from “head to foot”. Neem oil is
used primarily during the growing season when leaves and the offending insects are
present.
Neem oil is a bit “trendy” right now. And it is
plant-based rather than petroleum-based which for some is important. One major
difference between neem oil and horticultural oil is the “toxicity” of neem oil
toward some insects. Horticultural oil is not “toxic” on its own. It relies on “suffocating”
insects for control.
plant-based rather than petroleum-based which for some is important. One major
difference between neem oil and horticultural oil is the “toxicity” of neem oil
toward some insects. Horticultural oil is not “toxic” on its own. It relies on “suffocating”
insects for control.
Remember, just like many “organic” pest controlchemicals, neem oil is nondiscriminatory in what it kills. It cannot recognize
a good insect from a bad insect. You direct the spray towards pests you want to
control or food that you want to protect. This is also true of horticultural
oils but, unlike neem oil, is frequently applied when leaves and fruit are not
present.
Neem oil has been promoted for disease control. A little
known fact is that horticultural oils will control nearly all of the same
diseases as neem oil. Similarly, horticultural oils can be applied when leaves
and fruit are present as long as temperatures are below 80° F.
known fact is that horticultural oils will control nearly all of the same
diseases as neem oil. Similarly, horticultural oils can be applied when leaves
and fruit are present as long as temperatures are below 80° F.
Personally, I have never found neem oil particularly effective
in killing pests although I do use it in rotation with soaps and other organic
pest controls. I worry a little bit that there is a wide variation in the
“quality” of neem oils being produced and available on the market.
Horticultural oils are pretty much all the same. Stay with name brands of neem
oil.
in killing pests although I do use it in rotation with soaps and other organic
pest controls. I worry a little bit that there is a wide variation in the
“quality” of neem oils being produced and available on the market.
Horticultural oils are pretty much all the same. Stay with name brands of neem
oil.