Horticultural Oil

Pest Control Using Horticultural Oil

Horticultural oil is a great alternative to pesticides and can be just as effective! This oil is either petroleum or vegetable-based and are used to rid insects and other pests from plants. Natural oil is an organic way to kill insects from pests without harming the plants or larger animals which may come into contact with the area. This type of pest control first came into popularity with fruit trees, where the area could be treated for specific pests without damaging the fruit or harming the good insects, such as bees and butterflies which are necessary for pollinating the trees.

Using Horticultural Oil

Horticultural oil basically works by suffocating many varieties of adult insects and penetrating the eggs to prevent young insects from emerging. Some other types of insects, such as aphids, will merely be unable to feed from the plants but will not necessarily die from the oil itself. Because the main trait of this oil is to smother insects, humans and larger animals do not suffer from its presence.

To make up your own batch of horticultural oil, you will need to decide which oil you want to use. This oil has to be diluted using water and sometimes other agents in order for it to make a good spray. A generic recipe includes using one cup of vegetable oil and a tablespoon of dish soap to make the “special solution”. Two tablespoons of the special solution should be added to two cups of water. Double this as needed. Pour the oil mixture into a spray bottle and you’re ready to go.

Before you go to town on your plants, it is important to understand a few things about horticultural oil. Even though it is generally safe for plants, it is always a good idea to do a test run on the plants you intend to treat. You can do this by spraying one leaf on each type of plant. Check on it after three days to see whether any damage has occurred. If the plant appears to be fine, then it’s a safe bet that the oil mixture is okay to use. If the leaf looks like it has been burned or seems to be dying, DO NOT use the oil on that particular plant or try a different oil mixture. If the plant does not have a reaction to the oil, go ahead and spray the insects near the plant. You must spray the insects themselves with the oil because they have to come in contact with it. The oil lands on the insect and clogs its pores, resulting in suffocation. Thus, the more oil that the insect comes into contact with—the better!

When Horticultural Oil Should Not Be Used…

This oil is great when used correctly, but there are certain instances when it could do more harm than good. When the temperature outdoors becomes very hot—around 100 degrees F—the oil could intensify the sun’s heat. This can be especially harmful to plants that are already suffering from the sun’s heat or those which are predisposed to suffer during a drought. You should also avoid using horticultural oil during rainy weather, which can slow down the evaporation process. An area where a pesticide containing sulfur has been previously used should be given at least a month before the oil is applied, as the combination of sulfur and oil can be toxic to many plants. And finally, avoid using this oil mixture when the outdoor temperature is freezing, as this could make it difficult for the spray to spread evenly.