Pest insects like aphids and mites can infest your garden plants or your herbs, often eating away at them and ruining your gardens. Numerous chemicals on the market will help get rid of pest insects, but you may not want to use potentially harmful substances, especially if you're growing herbs that you're planning on eventually eating. Luckily, you can use garlic as a safe, natural alternative for killing off and repelling pests on plants.
Garlic oil can be very acidic and will burn the pest insects on the plant, keeping them at bay. The same oil works as a means for repelling such insects. Its strong scent, which is known for burning peoples' nostrils, works the same way with insects, which often have much stronger olfactory glands. They will be more affected by the scent of the bulb, keeping them away from the plant in the future.
To apply a garlic oil-based repellent to your plants, you will need a head of garlic to supply the oil, a cutting knife, a small pot of boiling water, a Mason jar with a tight-fitting lid, a blender, a strainer and a spray bottle. These materials will allow you to create a spray that contains garlic oils that you can use on your plants.
Dice the peeled garlic into little cubes and toss them in a blender along with 2 cups of boiling water. Mince the solution for about three minutes in the blender. Pour it into a Mmason jar and seal it tight, then let it sit for at least 12 hours, overnight if necessary. This will ensure that the water absorbs all of the released garlic oils. After 12 hours, strain the water from the jar into a spray bottle.
Spray the garlic solution onto the infested plants during the warmer hours of the day. This will allow the garlic solution to evaporate before it can stain your plant with a garlic-laced taste, though the oil itself will not hurt your plant; you can be more lenient with spraying on decorative plants. If the infestation is very severe, you may consider spraying the insects off with regular water first before applying the garlic spray. Repeat as necessary to stave off future infestations.
The severity of an infestation can be subjective, and therefore the exact procedure for created a garlic-based spray can be subjective as well. Many other gardeners will have different recipes, with some using more garlic than others and some even using a touch of soap in their mixtures. Experiment with different methods to figure out which works best for you and your situation.